# system

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The compiler depends on the System module to work properly and the System module depends on the compiler. Most of the routines listed here use special compiler magic.

Each module implicitly imports the System module; it must not be listed explicitly. Because of this there cannot be a user-defined module named `system`.

# System module

The System module imports several separate modules, and their documentation is in separate files:

- iterators
- assertions
- dollars
- io
- widestrs

Here is a short overview of the most commonly used functions from the `system` module. Function names in the tables below are clickable and will take you to the full documentation of the function.

The amount of available functions is much larger. Use the table of contents on the left-hand side and/or `Ctrl+F` to navigate through this module.

## Strings and characters

Proc | Usage
--- | ---
len(s) | Return the length of a string
chr(i) | Convert an `int` in the range `0..255` to a character
ord(c) | Return `int` value of a character
a & b | Concatenate two strings
s.add(c) | Add character to the string
$ | Convert various types to string

See also:

- strutils module for common string functions
- strformat module for string interpolation and formatting
- unicode module for Unicode UTF-8 handling
- strscans for `scanf` and `scanp` macros, which offer easier substring extraction than regular expressions
- strtabs module for efficient hash tables (dictionaries, in some programming languages) mapping from strings to strings

## Seqs

Proc | Usage
--- | ---
newSeq | Create a new sequence of a given length
newSeqOfCap | Create a new sequence with zero length and a given capacity
setLen | Set the length of a sequence
len | Return the length of a sequence
@ | Turn an array into a sequence
add | Add an item to the sequence
insert | Insert an item at a specific position
delete | Delete an item while preserving the order of elements (`O(n)` operation)
del | `O(1)` removal, doesn't preserve the order
pop | Remove and return last item of a sequence
x & y | Concatenate two sequences
x[a..b] | Slice of a sequence (both ends included)

See also:

- sequtils module for operations on container types (including strings)
- json module for a structure which allows heterogeneous members
- lists module for linked lists

## Sets

Built-in bit sets.

Proc | Usage
--- | ---
incl | Include element `y` in the set `x`
excl | Exclude element `y` from the set `x`
card | Return the cardinality of the set, i.e. the number of elements
a * b | Intersection
a + b | Union
a - b | Difference
contains | Check if an element is in the set
a < b | Check if `a` is a subset of `b`

See also:

- sets module for hash sets
- intsets module for efficient int sets

## Numbers

Proc | Usage | Also known as (in other languages)
--- | --- | ---
div | Integer division | `//`
mod | Integer modulo (remainder) | `%`
shl | Shift left | `<<`
shr | Shift right | `>>`
ashr | Arithmetic shift right |
and | Bitwise `and` | `&`
or | Bitwise `or` | `|`
xor | Bitwise `xor` | `^`
not | Bitwise `not` (complement) | `~`
toInt | Convert floating-point number into an `int` |
toFloat | Convert an integer into a `float` |

See also:

- math module for mathematical operations like trigonometric functions, logarithms, square and cubic roots, etc.
- complex module for operations on complex numbers
- rationals module for rational numbers

## Ordinals

Ordinal type includes integer, bool, character, and enumeration types, as well as their subtypes.

Proc | Usage
--- | ---
succ | Successor of the value
pred | Predecessor of the value
inc | Increment the ordinal
dec | Decrement the ordinal
high | Return the highest possible value
low | Return the lowest possible value
ord | Return `int` value of an ordinal value

## Misc

Proc | Usage
--- | ---
is | Check if two arguments are of the same type
isnot | Negated version of `is`
!= | Not equals
addr | Take the address of a memory location
T and F | Boolean `and`
T or F | Boolean `or`
T xor F | Boolean `xor` (exclusive or)
not T | Boolean `not`
a .. b | Binary slice that constructs an interval `[a, b]`
a ..< b | Interval `[a, b)` (excluded upper bound)
runnableExamples | Create testable documentation

# Imports

ansi_c, memory, assertions, iterators, dollars, formatfloat, widestrs, io

# Types

    int {...}{.magic: Int.}

  Default integer type; bitwidth depends on architecture, but is always the same as a pointer. Source Edit

    int8 {...}{.magic: Int8.}

  Signed 8 bit integer type. Source Edit

    int16 {...}{.magic: Int16.}

  Signed 16 bit integer type. Source Edit

    int32 {...}{.magic: Int32.}

  Signed 32 bit integer type. Source Edit

    int64 {...}{.magic: Int64.}

  Signed 64 bit integer type. Source Edit

    uint {...}{.magic: UInt.}

  Unsigned default integer type. Source Edit

    uint8 {...}{.magic: UInt8.}

  Unsigned 8 bit integer type. Source Edit

    uint16 {...}{.magic: UInt16.}

  Unsigned 16 bit integer type. Source Edit

    uint32 {...}{.magic: UInt32.}

  Unsigned 32 bit integer type. Source Edit

    uint64 {...}{.magic: UInt64.}

  Unsigned 64 bit integer type. Source Edit

    float {...}{.magic: Float.}

  Default floating point type. Source Edit

    float32 {...}{.magic: Float32.}

  32 bit floating point type. Source Edit

    float64 {...}{.magic: Float.}

  64 bit floating point type. Source Edit

    bool {...}{.magic: Bool.} = enum
      false = 0, true = 1

  Built-in boolean type. Source Edit

    char {...}{.magic: Char.}

  Built-in 8 bit character type (unsigned). Source Edit

    string {...}{.magic: String.}

  Built-in string type. Source Edit

    cstring {...}{.magic: Cstring.}

  Built-in cstring (compatible string) type. Source Edit

    pointer {...}{.magic: Pointer.}

  Built-in pointer type, use the `addr` operator to get a pointer to a variable. Source Edit

    typedesc {...}{.magic: TypeDesc.}

  Meta type to denote a type description. Source Edit

    Ordinal[T] {...}{.magic: Ordinal.}

  Generic ordinal type. Includes integer, bool, character, and enumeration types as well as their subtypes. Note `uint` and `uint64` are not ordinal types for implementation reasons. Source Edit

    ptr[T] {...}{.magic: Pointer.}

  Built-in generic untraced pointer type. Source Edit

    ref[T] {...}{.magic: Pointer.}

  Built-in generic traced pointer type. Source Edit

    void {...}{.magic: "VoidType".}

  Meta type to denote the absence of any type. Source Edit

    auto {...}{.magic: Expr.}

  Meta type for automatic type determination. Source Edit

    any = distinct auto

  Meta type for any supported type. Source Edit

    untyped {...}{.magic: Expr.}

  Meta type to denote an expression that is not resolved (for templates). Source Edit

    typed {...}{.magic: Stmt.}

  Meta type to denote an expression that is resolved (for templates). Source Edit

    SomeSignedInt = int | int8 | int16 | int32 | int64

  Type class matching all signed integer types. Source Edit

    SomeUnsignedInt = uint | uint8 | uint16 | uint32 | uint64

  Type class matching all unsigned integer types. Source Edit

    SomeInteger = SomeSignedInt | SomeUnsignedInt

  Type class matching all integer types. Source Edit

    SomeOrdinal = int | int8 | int16 | int32 | int64 | bool | enum | uint | uint8 | uint16 | uint32 |
        uint64

  Type class matching all ordinal types; however this includes enums with holes. Source Edit

    SomeFloat = float | float32 | float64

  Type class matching all floating point number types. Source Edit

    SomeNumber = SomeInteger | SomeFloat

  Type class matching all number types. Source Edit

    static[T] {...}{.magic: "Static".}

  Meta type representing all values that can be evaluated at compile-time.

  The type coercion `static(x)` can be used to force the compile-time evaluation of the given expression `x`.

  Source Edit

    type[T] {...}{.magic: "Type".}

  Meta type representing the type of all type values.

  The coercion `type(x)` can be used to obtain the type of the given expression `x`.

  Source Edit

    TypeOfMode = enum
      typeOfProc,                 ## Prefer the interpretation that means `x` is a proc call.
      typeOfIter                  ## Prefer the interpretation that means `x` is an iterator call.

  Possible modes of `typeof`. Source Edit

    range[T] {...}{.magic: "Range".}

  Generic type to construct range types. Source Edit

    array[I; T] {...}{.magic: "Array".}

  Generic type to construct fixed-length arrays. Source Edit

    openArray[T] {...}{.magic: "OpenArray".}

  Generic type to construct open arrays. Open arrays are implemented as a pointer to the array data and a length field. Source Edit

    varargs[T] {...}{.magic: "Varargs".}

  Generic type to construct a varargs type. Source Edit

    seq[T] {...}{.magic: "Seq".}

  Generic type to construct sequences. Source Edit

    set[T] {...}{.magic: "Set".}

  Generic type to construct bit sets. Source Edit

    UncheckedArray[T] {...}{.magic: "UncheckedArray".}

  Source Edit

    sink[T] {...}{.magic: "BuiltinType".}

  Source Edit

    lent[T] {...}{.magic: "BuiltinType".}

  Source Edit

    HSlice[T; U] = object
      a*: T                        ## The lower bound (inclusive).
      b*: U                        ## The upper bound (inclusive).

  "Heterogeneous" slice type. Source Edit

    Slice[T] = HSlice[T, T]

  An alias for `HSlice[T, T]`. Source Edit

    byte = uint8

  This is an alias for `uint8`, that is an unsigned integer, 8 bits wide. Source Edit

    Natural = range[0 .. high(int)]

  is an `int` type ranging from zero to the maximum value of an `int`. This type is often useful for documentation and debugging. Source Edit

    Positive = range[1 .. high(int)]

  is an `int` type ranging from one to the maximum value of an `int`. This type is often useful for documentation and debugging. Source Edit

    RootObj {...}{.compilerproc, inheritable.} = object

  The root of Nim's object hierarchy.

  Objects should inherit from `RootObj` or one of its descendants. However, objects that have no ancestor are also allowed.

  Source Edit

    RootRef = ref RootObj

  Reference to `RootObj`. Source Edit

    RootEffect {...}{.compilerproc.} = object of RootObj

  Base effect class.

  Each effect should inherit from `RootEffect` unless you know what you're doing.

  Source Edit

    TimeEffect = object of RootEffect

  Time effect. Source Edit

    IOEffect = object of RootEffect

  IO effect. Source Edit

    ReadIOEffect = object of IOEffect

  Effect describing a read IO operation. Source Edit

    WriteIOEffect = object of IOEffect

  Effect describing a write IO operation. Source Edit

    ExecIOEffect = object of IOEffect

  Effect describing an executing IO operation. Source Edit

    StackTraceEntry = object
      procname*: cstring           ## Name of the proc that is currently executing.
      line*: int                   ## Line number of the proc that is currently executing.
      filename*: cstring           ## Filename of the proc that is currently executing.

  In debug mode exceptions store the stack trace that led to them. A `StackTraceEntry` is a single entry of the stack trace. Source Edit

    Exception {...}{.compilerproc, magic: "Exception".} = object of RootObj
      parent*: ref Exception        ## Parent exception (can be used as a stack).
      name*: cstring               ## The exception's name is its Nim identifier.
                   ## This field is filled automatically in the
                   ## ``raise`` statement.
      msg* {...}{.exportc: "message".}: string ## The exception's message. Not
                                      ## providing an exception message
                                      ## is bad style.
      when defined(js):
          trace: string

      else:
          trace: seq[StackTraceEntry]

      when defined(nimBoostrapCsources0_19_0):
          raise_id: uint

      else:
          raiseId: uint

      up: ref Exception

  Base exception class.

  Each exception has to inherit from `Exception`. See the full exception hierarchy.

  Source Edit

    Defect = object of Exception

  Abstract base class for all exceptions that Nim's runtime raises but that are strictly uncatchable as they can also be mapped to a `quit` / `trap` / `exit` operation. Source Edit

    CatchableError = object of Exception

  Abstract class for all exceptions that are catchable. Source Edit

    IOError = object of CatchableError

  Raised if an IO error occurred. Source Edit

    EOFError = object of IOError

  Raised if an IO "end of file" error occurred. Source Edit

    OSError = object of CatchableError
      errorCode*: int32            ## OS-defined error code describing this error.

  Raised if an operating system service failed. Source Edit

    LibraryError = object of OSError

  Raised if a dynamic library could not be loaded. Source Edit

    ResourceExhaustedError = object of CatchableError

  Raised if a resource request could not be fulfilled. Source Edit

    ArithmeticError = object of Defect

  Raised if any kind of arithmetic error occurred. Source Edit

    DivByZeroError = object of ArithmeticError

  Raised for runtime integer divide-by-zero errors. Source Edit

    OverflowError = object of ArithmeticError

  Raised for runtime integer overflows.

  This happens for calculations whose results are too large to fit in the provided bits.

  Source Edit

    AccessViolationError = object of Defect

  Raised for invalid memory access errors Source Edit

    AssertionError = object of Defect

  Raised when assertion is proved wrong.

  Usually the result of using the assert() template.

  Source Edit

    ValueError = object of CatchableError

  Raised for string and object conversion errors. Source Edit

    KeyError = object of ValueError

  Raised if a key cannot be found in a table.

  Mostly used by the tables module, it can also be raised by other collection modules like sets or strtabs.

  Source Edit

    OutOfMemError = object of Defect

  Raised for unsuccessful attempts to allocate memory. Source Edit

    IndexError = object of Defect

  Raised if an array index is out of bounds. Source Edit

    FieldError = object of Defect

  Raised if a record field is not accessible because its dicriminant's value does not fit. Source Edit

    RangeError = object of Defect

  Raised if a range check error occurred. Source Edit

    StackOverflowError = object of Defect

  Raised if the hardware stack used for subroutine calls overflowed. Source Edit

    ReraiseError = object of Defect

  Raised if there is no exception to reraise. Source Edit

    ObjectAssignmentError = object of Defect

  Raised if an object gets assigned to its parent's object. Source Edit

    ObjectConversionError = object of Defect

  Raised if an object is converted to an incompatible object type. You can use `of` operator to check if conversion will succeed. Source Edit

    FloatingPointError = object of Defect

  Base class for floating point exceptions. Source Edit

    FloatInvalidOpError = object of FloatingPointError

  Raised by invalid operations according to IEEE.

  Raised by `0.0/0.0`, for example.

  Source Edit

    FloatDivByZeroError = object of FloatingPointError

  Raised by division by zero.

  Divisor is zero and dividend is a finite nonzero number.

  Source Edit

    FloatOverflowError = object of FloatingPointError

  Raised for overflows.

  The operation produced a result that exceeds the range of the exponent.

  Source Edit

    FloatUnderflowError = object of FloatingPointError

  Raised for underflows.

  The operation produced a result that is too small to be represented as a normal number.

  Source Edit

    FloatInexactError = object of FloatingPointError

  Raised for inexact results.

  The operation produced a result that cannot be represented with infinite precision -- for example: `2.0 / 3.0, log(1.1)`

  Note: Nim currently does not detect these!

  Source Edit

    DeadThreadError = object of Defect

  Raised if it is attempted to send a message to a dead thread. Source Edit

    NilAccessError = object of Defect

  Raised on dereferences of `nil` pointers.

  This is only raised if the segfaults module was imported!

  Source Edit

    JsRoot = ref object of RootObj

  Root type of the JavaScript object hierarchy Source Edit

    owned[T] {...}{.magic: "BuiltinType".}

  type constructor to mark a ref/ptr or a closure as `owned`. Source Edit

    Endianness = enum
      littleEndian, bigEndian

  Type describing the endianness of a processor. Source Edit

    TaintedString = string

  A distinct string type that is tainted, see taint mode for details. It is an alias for `string` if the taint mode is not turned on. Source Edit

    ByteAddress = int

  is the signed integer type that should be used for converting pointers to integer addresses for readability. Source Edit

    BiggestInt = int64

  is an alias for the biggest signed integer type the Nim compiler supports. Currently this is `int64`, but it is platform-dependant in general. Source Edit

    BiggestFloat = float64

  is an alias for the biggest floating point type the Nim compiler supports. Currently this is `float64`, but it is platform-dependant in general. Source Edit

    BiggestUInt = uint64

  is an alias for the biggest unsigned integer type the Nim compiler supports. Currently this is `uint32` for JS and `uint64` for other targets. Source Edit

    clong {...}{.importc: "long", nodecl.} = int32

  This is the same as the type `long` in C. Source Edit

    culong {...}{.importc: "unsigned long", nodecl.} = uint32

  This is the same as the type `unsigned long` in C. Source Edit

    cchar {...}{.importc: "char", nodecl.} = char

  This is the same as the type `char` in C. Source Edit

    cschar {...}{.importc: "signed char", nodecl.} = int8

  This is the same as the type `signed char` in C. Source Edit

    cshort {...}{.importc: "short", nodecl.} = int16

  This is the same as the type `short` in C. Source Edit

    cint {...}{.importc: "int", nodecl.} = int32

  This is the same as the type `int` in C. Source Edit

    csize {...}{.importc: "size_t", nodecl.} = int

  This is the same as the type `size_t` in C. Source Edit

    clonglong {...}{.importc: "long long", nodecl.} = int64

  This is the same as the type `long long` in C. Source Edit

    cfloat {...}{.importc: "float", nodecl.} = float32

  This is the same as the type `float` in C. Source Edit

    cdouble {...}{.importc: "double", nodecl.} = float64

  This is the same as the type `double` in C. Source Edit

    clongdouble {...}{.importc: "long double", nodecl.} = BiggestFloat

  This is the same as the type `long double` in C. This C type is not supported by Nim's code generator. Source Edit

    cuchar {...}{.importc: "unsigned char", nodecl.} = char

  This is the same as the type `unsigned char` in C. Source Edit

    cushort {...}{.importc: "unsigned short", nodecl.} = uint16

  This is the same as the type `unsigned short` in C. Source Edit

    cuint {...}{.importc: "unsigned int", nodecl.} = uint32

  This is the same as the type `unsigned int` in C. Source Edit

    culonglong {...}{.importc: "unsigned long long", nodecl.} = uint64

  This is the same as the type `unsigned long long` in C. Source Edit

    cstringArray {...}{.importc: "char**", nodecl.} = ptr UncheckedArray[cstring]

  This is binary compatible to the type `char**` in C. The array's high value is large enough to disable bounds checking in practice. Use cstringArrayToSeq proc to convert it into a `seq[string]`. Source Edit

    PFloat32 = ptr float32

  An alias for `ptr float32`. Source Edit

    PFloat64 = ptr float64

  An alias for `ptr float64`. Source Edit

    PInt64 = ptr int64

  An alias for `ptr int64`. Source Edit

    PInt32 = ptr int32

  An alias for `ptr int32`. Source Edit

    AtomType = SomeNumber | pointer | ptr | char | bool

  Type Class representing valid types for use with atomic procs Source Edit

    GC_Strategy = enum
      gcThroughput,               ## optimize for throughput
      gcResponsiveness,           ## optimize for responsiveness (default)
      gcOptimizeTime,             ## optimize for speed
      gcOptimizeSpace             ## optimize for memory footprint

  The strategy the GC should use for the application. Source Edit

    PFrame = ptr TFrame

  Represents a runtime frame of the call stack; part of the debugger API. Source Edit

    TFrame {...}{.importc, nodecl, final.} = object
      prev*: PFrame                ## Previous frame; used for chaining the call stack.
      procname*: cstring           ## Name of the proc that is currently executing.
      line*: int                   ## Line number of the proc that is currently executing.
      filename*: cstring           ## Filename of the proc that is currently executing.
      len*: int16                  ## Length of the inspectable slots.
      calldepth*: int16            ## Used for max call depth checking.

  The frame itself. Source Edit

    FileSeekPos = enum
      fspSet,                     ## Seek to absolute value
      fspCur,                     ## Seek relative to current position
      fspEnd                      ## Seek relative to end

  Position relative to which seek should happen. Source Edit

    ForeignCell = object
      data*: pointer
      owner: ptr GcHeap

  Source Edit

    BackwardsIndex = distinct int

  Type that is constructed by `^` for reversed array accesses. (See ^ template) Source Edit

    NimNode {...}{.magic: "PNimrodNode".} = ref NimNodeObj

  Represents a Nim AST node. Macros operate on this type. Source Edit

    ForLoopStmt {...}{.compilerproc.} = object

  A special type that marks a macro as a for-loop macro. See "For Loop Macro". Source Edit

# Vars

    programResult: int

  deprecated, prefer `quit` Source Edit

    globalRaiseHook: proc (e: ref Exception): bool {...}{.nimcall, gcsafe, locks: 0.}

  With this hook you can influence exception handling on a global level. If not nil, every 'raise' statement ends up calling this hook.

  Warning: Ordinary application code should never set this hook! You better know what you do when setting this.

  If `globalRaiseHook` returns false, the exception is caught and does not propagate further through the call stack.

  Source Edit

    localRaiseHook: proc (e: ref Exception): bool {...}{.nimcall, gcsafe, locks: 0.}

  With this hook you can influence exception handling on a thread local level. If not nil, every 'raise' statement ends up calling this hook.

  Warning: Ordinary application code should never set this hook! You better know what you do when setting this.

  If `localRaiseHook` returns false, the exception is caught and does not propagate further through the call stack.

  Source Edit

    outOfMemHook: proc () {...}{.nimcall, tags: [], gcsafe, locks: 0, raises: [].}

  Set this variable to provide a procedure that should be called in case of an out of memory event. The standard handler writes an error message and terminates the program.

  `outOfMemHook` can be used to raise an exception in case of OOM like so:

      var gOutOfMem: ref EOutOfMemory
      new(gOutOfMem) # need to be allocated *before* OOM really happened!
      gOutOfMem.msg = "out of memory"

      proc handleOOM() =
        raise gOutOfMem

      system.outOfMemHook = handleOOM

  If the handler does not raise an exception, ordinary control flow continues and the program is terminated.

  Source Edit

    errorMessageWriter: (proc (msg: string) {...}{.tags: [WriteIOEffect], gcsafe, locks: 0,
                                          nimcall.})

  Function that will be called instead of `stdmsg.write` when printing stacktrace. Unstable API. Source Edit

    onUnhandledException: (proc (errorMsg: string) {...}{.nimcall.})

  Set this error handler to override the existing behaviour on an unhandled exception.

  The default is to write a stacktrace to `stderr` and then call `quit(1)`. Unstable API.

  Source Edit

# Lets

    nimvm: bool = false

  May be used only in `when` expression. It is true in Nim VM context and false otherwise. Source Edit

# Consts

    on = true

  Alias for `true`. Source Edit

    off = false

  Alias for `false`. Source Edit

    appType: string = ""

  A string that describes the application type. Possible values: `"console"`, `"gui"`, `"lib"`. Source Edit

    NoFakeVars = false

  `true` if the backend doesn't support "fake variables" like `var EBADF {.importc.}: cint`. Source Edit

    isMainModule: bool = false

  True only when accessed in the main module. This works thanks to compiler magic. It is useful to embed testing code in a module. Source Edit

    CompileDate: string = "0000-00-00"

  The date (in UTC) of compilation as a string of the form `YYYY-MM-DD`. This works thanks to compiler magic. Source Edit

    CompileTime: string = "00:00:00"

  The time (in UTC) of compilation as a string of the form `HH:MM:SS`. This works thanks to compiler magic. Source Edit

    cpuEndian: Endianness = littleEndian

  The endianness of the target CPU. This is a valuable piece of information for low-level code only. This works thanks to compiler magic. Source Edit

    hostOS: string = ""

  A string that describes the host operating system.

  Possible values: `"windows"`, `"macosx"`, `"linux"`, `"netbsd"`, `"freebsd"`, `"openbsd"`, `"solaris"`, `"aix"`, `"haiku"`, `"standalone"`.

  Source Edit

    hostCPU: string = ""

  A string that describes the host CPU.

  Possible values: `"i386"`, `"alpha"`, `"powerpc"`, `"powerpc64"`, `"powerpc64el"`, `"sparc"`, `"amd64"`, `"mips"`, `"mipsel"`, `"arm"`, `"arm64"`, `"mips64"`, `"mips64el"`, `"riscv64"`.

  Source Edit

    nimEnableCovariance = false

  Source Edit

    QuitSuccess = 0

  is the value that should be passed to quit to indicate success. Source Edit

    QuitFailure = 1

  is the value that should be passed to quit to indicate failure. Source Edit

    Inf = 0x0000000000000000'f64

  Contains the IEEE floating point value of positive infinity. Source Edit

    NegInf = 0x0000000000000000'f64

  Contains the IEEE floating point value of negative infinity. Source Edit

    NaN = 0x0000000000000000'f64

  Contains an IEEE floating point value of Not A Number.

  Note that you cannot compare a floating point value to this value and expect a reasonable result - use the `classify` procedure in the math module for checking for NaN.

  Source Edit

    nimCoroutines = false

  Source Edit

    NimMajor: int = 1

  is the major number of Nim's version. Source Edit

    NimMinor: int = 0

  is the minor number of Nim's version. Source Edit

    NimPatch: int = 2

  is the patch number of Nim's version. Source Edit

    NimVersion: string = "1.0.2"

  is the version of Nim as a string. Source Edit

    nativeStackTraceSupported = false

  Source Edit

# Procs

    proc `or`(a, b: typedesc): typedesc {...}{.magic: "TypeTrait", noSideEffect.}

  Constructs an `or` meta class. Source Edit

    proc `and`(a, b: typedesc): typedesc {...}{.magic: "TypeTrait", noSideEffect.}

  Constructs an `and` meta class. Source Edit

    proc `not`(a: typedesc): typedesc {...}{.magic: "TypeTrait", noSideEffect.}

  Constructs an `not` meta class. Source Edit

    proc defined(x: untyped): bool {...}{.magic: "Defined", noSideEffect, compileTime.}

  Special compile-time procedure that checks whether `x` is defined.

  `x` is an external symbol introduced through the compiler's -d:x switch to enable build time conditionals:

      when not defined(release):
        # Do here programmer friendly expensive sanity checks.
      # Put here the normal code

  Source Edit

    proc runnableExamples(body: untyped) {...}{.magic: "RunnableExamples".}

  A section you should use to mark runnable example code with.
  - In normal debug and release builds code within a `runnableExamples` section is ignored.
  - The documentation generator is aware of these examples and considers them part of the `##` doc comment. As the last step of documentation generation each runnableExample is put in its own file `$file_examples$i.nim`, compiled and tested. The collected examples are put into their own module to ensure the examples do not refer to non-exported symbols.

  Usage:

      proc double*(x: int): int =
        ## This proc doubles a number.
        runnableExamples:
          ## at module scope
          assert double(5) == 10
          block: ## at block scope
            defer: echo "done"

        result = 2 * x

  Source Edit

    proc declared(x: untyped): bool {...}{.magic: "Defined", noSideEffect, compileTime.}

  Special compile-time procedure that checks whether `x` is declared. `x` has to be an identifier or a qualified identifier.

  See also:

  - declaredInScope

  This can be used to check whether a library provides a certain feature or not:

      when not declared(strutils.toUpper):
        # provide our own toUpper proc here, because strutils is
        # missing it.

  Source Edit

    proc declaredInScope(x: untyped): bool {...}{.magic: "DefinedInScope", noSideEffect,
                                         compileTime.}

  Special compile-time procedure that checks whether `x` is declared in the current scope. `x` has to be an identifier. Source Edit

    proc `addr`[T](x: var T): ptr T {...}{.magic: "Addr", noSideEffect.}

  Builtin `addr` operator for taking the address of a memory location. Cannot be overloaded.

  See also:

  - unsafeAddr

      var
        buf: seq[char] = @['a','b','c']
        p = buf[1].addr
      echo p.repr # ref 0x7faa35c40059 --> 'b'
      echo p[]    # b

  Source Edit

    proc unsafeAddr[T](x: T): ptr T {...}{.magic: "Addr", noSideEffect.}

  Builtin `addr` operator for taking the address of a memory location. This works even for `let` variables or parameters for better interop with C and so it is considered even more unsafe than the ordinary addr.

  Note: When you use it to write a wrapper for a C library, you should always check that the original library does never write to data behind the pointer that is returned from this procedure.

  Cannot be overloaded.

  Source Edit

    proc typeof(x: untyped; mode = typeOfIter): typedesc {...}{.magic: "TypeOf", noSideEffect,
        compileTime.}

  Builtin `typeof` operation for accessing the type of an expression. Since version 0.20.0. Source Edit

    proc `not`(x: bool): bool {...}{.magic: "Not", noSideEffect.}

  Boolean not; returns true if `x == false`. Source Edit

    proc `and`(x, y: bool): bool {...}{.magic: "And", noSideEffect.}

  Boolean `and`; returns true if `x == y == true` (if both arguments are true).

  Evaluation is lazy: if `x` is false, `y` will not even be evaluated.

  Source Edit

    proc `or`(x, y: bool): bool {...}{.magic: "Or", noSideEffect.}

  Boolean `or`; returns true if `not (not x and not y)` (if any of the arguments is true).

  Evaluation is lazy: if `x` is true, `y` will not even be evaluated.

  Source Edit

    proc `xor`(x, y: bool): bool {...}{.magic: "Xor", noSideEffect.}

  Boolean `exclusive or`; returns true if `x != y` (if either argument is true while the other is false). Source Edit

    proc internalNew[T](a: var ref T) {...}{.magic: "New", noSideEffect.}

  Leaked implementation detail. Do not use. Source Edit

    proc new[T](a: var ref T; finalizer: proc (x: ref T) {...}{.nimcall.}) {...}{.magic: "NewFinalize",
        noSideEffect.}

  Creates a new object of type `T` and returns a safe (traced) reference to it in `a`.

  When the garbage collector frees the object, `finalizer` is called. The `finalizer` may not keep a reference to the object pointed to by `x`. The `finalizer` cannot prevent the GC from freeing the object.

  Note: The `finalizer` refers to the type `T`, not to the object! This means that for each object of type `T` the finalizer will be called!

  Source Edit

    proc reset[T](obj: var T) {...}{.magic: "Reset", noSideEffect.}

  Old runtime target: Resets an object `obj` to its initial (binary zero) value.

  New runtime target: An alias for `=destroy`.

  Source Edit

    proc wasMoved[T](obj: var T) {...}{.magic: "WasMoved", noSideEffect.}

  Resets an object `obj` to its initial (binary zero) value to signify it was "moved" and to signify its destructor should do nothing and ideally be optimized away. Source Edit

    proc move[T](x: var T): T {...}{.magic: "Move", noSideEffect.}

  Source Edit

    proc high[T: Ordinal | enum | range](x: T): T {...}{.magic: "High", noSideEffect.}

  Returns the highest possible value of an ordinal value `x`.

  As a special semantic rule, `x` may also be a type identifier.

  See also:

  - low(T)

      high(2) # => 9223372036854775807

  Source Edit

    proc high[T: Ordinal | enum | range](x: typedesc[T]): T {...}{.magic: "High", noSideEffect.}

  Returns the highest possible value of an ordinal or enum type.

  `high(int)` is Nim's way of writing INT_MAX or MAX_INT.

  See also:

  - low(typedesc)

      high(int) # => 9223372036854775807

  Source Edit

    proc high[T](x: openArray[T]): int {...}{.magic: "High", noSideEffect.}

  Returns the highest possible index of a sequence `x`.

  See also:

  - low(openArray)

      var s = @[1, 2, 3, 4, 5, 6, 7]
      high(s) # => 6
      for i in low(s)..high(s):
        echo s[i]

  Source Edit

    proc high[I, T](x: array[I, T]): I {...}{.magic: "High", noSideEffect.}

  Returns the highest possible index of an array `x`.

  See also:

  - low(array)

      var arr = [1, 2, 3, 4, 5, 6, 7]
      high(arr) # => 6
      for i in low(arr)..high(arr):
        echo arr[i]

  Source Edit

    proc high[I, T](x: typedesc[array[I, T]]): I {...}{.magic: "High", noSideEffect.}

  Returns the highest possible index of an array type.

  See also:

  - low(typedesc[array])

      high(array[7, int]) # => 6

  Source Edit

    proc high(x: cstring): int {...}{.magic: "High", noSideEffect.}

  Returns the highest possible index of a compatible string `x`. This is sometimes an O(n) operation.

  See also:

  - low(cstring)
  Source Edit

    proc high(x: string): int {...}{.magic: "High", noSideEffect.}

  Returns the highest possible index of a string `x`.

  See also:

  - low(string)

      var str = "Hello world!"
      high(str) # => 11

  Source Edit

    proc low[T: Ordinal | enum | range](x: T): T {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible value of an ordinal value `x`. As a special semantic rule, `x` may also be a type identifier.

  See also:

  - high(T)

      low(2) # => -9223372036854775808

  Source Edit

    proc low[T: Ordinal | enum | range](x: typedesc[T]): T {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible value of an ordinal or enum type.

  `low(int)` is Nim's way of writing INT_MIN or MIN_INT.

  See also:

  - high(typedesc)

      low(int) # => -9223372036854775808

  Source Edit

    proc low[T](x: openArray[T]): int {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible index of a sequence `x`.

  See also:

  - high(openArray)

      var s = @[1, 2, 3, 4, 5, 6, 7]
      low(s) # => 0
      for i in low(s)..high(s):
        echo s[i]

  Source Edit

    proc low[I, T](x: array[I, T]): I {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible index of an array `x`.

  See also:

  - high(array)

      var arr = [1, 2, 3, 4, 5, 6, 7]
      low(arr) # => 0
      for i in low(arr)..high(arr):
        echo arr[i]

  Source Edit

    proc low[I, T](x: typedesc[array[I, T]]): I {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible index of an array type.

  See also:

  - high(typedesc[array])

      low(array[7, int]) # => 0

  Source Edit

    proc low(x: cstring): int {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible index of a compatible string `x`.

  See also:

  - high(cstring)
  Source Edit

    proc low(x: string): int {...}{.magic: "Low", noSideEffect.}

  Returns the lowest possible index of a string `x`.

  See also:

  - high(string)

      var str = "Hello world!"
      low(str) # => 0

  Source Edit

    proc shallowCopy[T](x: var T; y: T) {...}{.noSideEffect, magic: "ShallowCopy".}

  Use this instead of `=` for a shallow copy.

  The shallow copy only changes the semantics for sequences and strings (and types which contain those).

  Be careful with the changed semantics though! There is a reason why the default assignment does a deep copy of sequences and strings.

  Source Edit

    proc `[]`[I: Ordinal; T](a: T; i: I): T {...}{.noSideEffect, magic: "ArrGet".}

  Source Edit

    proc `[]=`[I: Ordinal; T, S](a: T; i: I; x: S) {...}{.noSideEffect, magic: "ArrPut".}

  Source Edit

    proc `=`[T](dest: var T; src: T) {...}{.noSideEffect, magic: "Asgn".}

  Source Edit

    proc `=destroy`[T](x: var T) {...}{.inline, magic: "Destroy".}

  Generic destructor implementation that can be overridden. Source Edit

    proc `=sink`[T](x: var T; y: T) {...}{.inline, magic: "Asgn".}

  Generic sink implementation that can be overridden. Source Edit

    proc `..`[T, U](a: T; b: U): HSlice[T, U] {...}{.noSideEffect, inline, magic: "DotDot".}

  Binary slice operator that constructs an interval `[a, b]`, both `a` and `b` are inclusive.

  Slices can also be used in the set constructor and in ordinal case statements, but then they are special-cased by the compiler.

      let a = [10, 20, 30, 40, 50]
      echo a[2 .. 3] # @[30, 40]

  Source Edit

    proc `..`[T](b: T): HSlice[int, T] {...}{.noSideEffect, inline, magic: "DotDot".}

  Unary slice operator that constructs an interval `[default(int), b]`.

      let a = [10, 20, 30, 40, 50]
      echo a[.. 2] # @[10, 20, 30]

  Source Edit

    proc `==`[Enum: enum](x, y: Enum): bool {...}{.magic: "EqEnum", noSideEffect.}

  Checks whether values within the same enum have the same underlying value.

      type
        Enum1 = enum
          Field1 = 3, Field2
        Enum2 = enum
          Place1, Place2 = 3
      var
        e1 = Field1
        e2 = Enum1(Place2)
      echo (e1 == e2) # true
      echo (e1 == Place2) # raises error

  Source Edit

    proc `==`(x, y: pointer): bool {...}{.magic: "EqRef", noSideEffect.}

      var # this is a wildly dangerous example
        a = cast[pointer](0)
        b = cast[pointer](nil)
      echo (a == b) # true due to the special meaning of `nil`/0 as a pointer

  Source Edit

    proc `==`(x, y: string): bool {...}{.magic: "EqStr", noSideEffect.}

  Checks for equality between two `string` variables. Source Edit

    proc `==`(x, y: char): bool {...}{.magic: "EqCh", noSideEffect.}

  Checks for equality between two `char` variables. Source Edit

    proc `==`(x, y: bool): bool {...}{.magic: "EqB", noSideEffect.}

  Checks for equality between two `bool` variables. Source Edit

    proc `==`[T](x, y: set[T]): bool {...}{.magic: "EqSet", noSideEffect.}

  Checks for equality between two variables of type `set`.

      var a = {1, 2, 2, 3} # duplication in sets is ignored
      var b = {1, 2, 3}
      echo (a == b) # true

  Source Edit

    proc `==`[T](x, y: ref T): bool {...}{.magic: "EqRef", noSideEffect.}

  Checks that two `ref` variables refer to the same item. Source Edit

    proc `==`[T](x, y: ptr T): bool {...}{.magic: "EqRef", noSideEffect.}

  Checks that two `ptr` variables refer to the same item. Source Edit

    proc `==`[T: proc](x, y: T): bool {...}{.magic: "EqProc", noSideEffect.}

  Checks that two `proc` variables refer to the same procedure. Source Edit

    proc `<=`[Enum: enum](x, y: Enum): bool {...}{.magic: "LeEnum", noSideEffect.}

  Source Edit

    proc `<=`(x, y: string): bool {...}{.magic: "LeStr", noSideEffect.}

  Compares two strings and returns true if `x` is lexicographically before `y` (uppercase letters come before lowercase letters).

      let
        a = "abc"
        b = "abd"
        c = "ZZZ"
      assert a <= b
      assert a <= a
      assert (a <= c) == false

  Source Edit

    proc `<=`(x, y: char): bool {...}{.magic: "LeCh", noSideEffect.}

  Compares two chars and returns true if `x` is lexicographically before `y` (uppercase letters come before lowercase letters).

      let
        a = 'a'
        b = 'b'
        c = 'Z'
      assert a <= b
      assert a <= a
      assert (a <= c) == false

  Source Edit

    proc `<=`[T](x, y: set[T]): bool {...}{.magic: "LeSet", noSideEffect.}

  Returns true if `x` is a subset of `y`.

  A subset `x` has all of its members in `y` and `y` doesn't necessarily have more members than `x`. That is, `x` can be equal to `y`.

      let
        a = {3, 5}
        b = {1, 3, 5, 7}
        c = {2}
      assert a <= b
      assert a <= a
      assert (a <= c) == false

  Source Edit

    proc `<=`(x, y: bool): bool {...}{.magic: "LeB", noSideEffect.}

  Source Edit

    proc `<=`[T](x, y: ref T): bool {...}{.magic: "LePtr", noSideEffect.}

  Source Edit

    proc `<=`(x, y: pointer): bool {...}{.magic: "LePtr", noSideEffect.}

  Source Edit

    proc `<`[Enum: enum](x, y: Enum): bool {...}{.magic: "LtEnum", noSideEffect.}

  Source Edit

    proc `<`(x, y: string): bool {...}{.magic: "LtStr", noSideEffect.}

  Compares two strings and returns true if `x` is lexicographically before `y` (uppercase letters come before lowercase letters).

      let
        a = "abc"
        b = "abd"
        c = "ZZZ"
      assert a < b
      assert (a < a) == false
      assert (a < c) == false

  Source Edit

    proc `<`(x, y: char): bool {...}{.magic: "LtCh", noSideEffect.}

  Compares two chars and returns true if `x` is lexicographically before `y` (uppercase letters come before lowercase letters).

      let
        a = 'a'
        b = 'b'
        c = 'Z'
      assert a < b
      assert (a < a) == false
      assert (a < c) == false

  Source Edit

    proc `<`[T](x, y: set[T]): bool {...}{.magic: "LtSet", noSideEffect.}

  Returns true if `x` is a strict or proper subset of `y`.

  A strict or proper subset `x` has all of its members in `y` but `y` has more elements than `y`.

      let
        a = {3, 5}
        b = {1, 3, 5, 7}
        c = {2}
      assert a < b
      assert (a < a) == false
      assert (a < c) == false

  Source Edit

    proc `<`(x, y: bool): bool {...}{.magic: "LtB", noSideEffect.}

  Source Edit

    proc `<`[T](x, y: ref T): bool {...}{.magic: "LtPtr", noSideEffect.}

  Source Edit

    proc `<`[T](x, y: ptr T): bool {...}{.magic: "LtPtr", noSideEffect.}

  Source Edit

    proc `<`(x, y: pointer): bool {...}{.magic: "LtPtr", noSideEffect.}

  Source Edit

    proc unsafeNew[T](a: var ref T; size: Natural) {...}{.magic: "New", noSideEffect.}

  Creates a new object of type `T` and returns a safe (traced) reference to it in `a`.

  This is unsafe as it allocates an object of the passed `size`. This should only be used for optimization purposes when you know what you're doing!

  See also:

  - new
  Source Edit

    proc sizeof[T](x: T): int {...}{.magic: "SizeOf", noSideEffect.}

  Returns the size of `x` in bytes.

  Since this is a low-level proc, its usage is discouraged - using new for the most cases suffices that one never needs to know `x`'s size.

  As a special semantic rule, `x` may also be a type identifier (`sizeof(int)` is valid).

  Limitations: If used for types that are imported from C or C++, sizeof should fallback to the `sizeof` in the C compiler. The result isn't available for the Nim compiler and therefore can't be used inside of macros.

      sizeof('A') # => 1
      sizeof(2) # => 8

  Source Edit

    proc alignof[T](x: T): int {...}{.magic: "AlignOf", noSideEffect.}

  Source Edit

    proc alignof(x: typedesc): int {...}{.magic: "AlignOf", noSideEffect.}

  Source Edit

    proc sizeof(x: typedesc): int {...}{.magic: "SizeOf", noSideEffect.}

  Source Edit

    proc `<`[T](x: Ordinal[T]): T {...}{.magic: "UnaryLt", noSideEffect, deprecated.}

  Deprecated

  Deprecated since version 0.18.0. For the common excluding range write `0 ..< 10` instead of `0 .. < 10` (look at the spacing). For `<x` write `pred(x)`.

  Unary `<` that can be used for excluding ranges. Semantically this is the same as pred.

      for i in 0 .. <10: echo i # => 0 1 2 3 4 5 6 7 8 9

  Source Edit

    proc succ[T: Ordinal](x: T; y = 1): T {...}{.magic: "Succ", noSideEffect.}

  Returns the `y`-th successor (default: 1) of the value `x`. `T` has to be an ordinal type.

  If such a value does not exist, `OverflowError` is raised or a compile time error occurs.

      let x = 5
      echo succ(5)    # => 6
      echo succ(5, 3) # => 8

  Source Edit

    proc pred[T: Ordinal](x: T; y = 1): T {...}{.magic: "Pred", noSideEffect.}

  Returns the `y`-th predecessor (default: 1) of the value `x`. `T` has to be an ordinal type.

  If such a value does not exist, `OverflowError` is raised or a compile time error occurs.

      let x = 5
      echo pred(5)    # => 4
      echo pred(5, 3) # => 2

  Source Edit

    proc inc[T: Ordinal | uint | uint64](x: var T; y = 1) {...}{.magic: "Inc", noSideEffect.}

  Increments the ordinal `x` by `y`.

  If such a value does not exist, `OverflowError` is raised or a compile time error occurs. This is a short notation for: `x = succ(x, y)`.

      var i = 2
      inc(i)    # i <- 3
      inc(i, 3) # i <- 6

  Source Edit

    proc dec[T: Ordinal | uint | uint64](x: var T; y = 1) {...}{.magic: "Dec", noSideEffect.}

  Decrements the ordinal `x` by `y`.

  If such a value does not exist, `OverflowError` is raised or a compile time error occurs. This is a short notation for: `x = pred(x, y)`.

      var i = 2
      dec(i)    # i <- 1
      dec(i, 3) # i <- -2

  Source Edit

    proc newSeq[T](s: var seq[T]; len: Natural) {...}{.magic: "NewSeq", noSideEffect.}

  Creates a new sequence of type `seq[T]` with length `len`.

  This is equivalent to `s = @[]; setlen(s, len)`, but more efficient since no reallocation is needed.

  Note that the sequence will be filled with zeroed entries. After the creation of the sequence you should assign entries to the sequence instead of adding them. Example:

      var inputStrings : seq[string]
      newSeq(inputStrings, 3)
      assert len(inputStrings) == 3
      inputStrings[0] = "The fourth"
      inputStrings[1] = "assignment"
      inputStrings[2] = "would crash"
      #inputStrings[3] = "out of bounds"

  Source Edit

    proc newSeq[T](len = 0.Natural): seq[T]

  Creates a new sequence of type `seq[T]` with length `len`.

  Note that the sequence will be filled with zeroed entries. After the creation of the sequence you should assign entries to the sequence instead of adding them.

  See also:

  - newSeqOfCap
  - newSeqUninitialized

      var inputStrings = newSeq[string](3)
      assert len(inputStrings) == 3
      inputStrings[0] = "The fourth"
      inputStrings[1] = "assignment"
      inputStrings[2] = "would crash"
      #inputStrings[3] = "out of bounds"

  Source Edit

    proc newSeqOfCap[T](cap: Natural): seq[T] {...}{.magic: "NewSeqOfCap", noSideEffect.}

  Creates a new sequence of type `seq[T]` with length zero and capacity `cap`.

      var x = newSeqOfCap[int](5)
      assert len(x) == 0
      x.add(10)
      assert len(x) == 1

  Source Edit

    proc newSeqUninitialized[T: SomeNumber](len: Natural): seq[T]

  Creates a new sequence of type `seq[T]` with length `len`.

  Only available for numbers types. Note that the sequence will be uninitialized. After the creation of the sequence you should assign entries to the sequence instead of adding them.

      var x = newSeqUninitialized[int](3)
      assert len(x) == 3
      x[0] = 10

  Source Edit

    proc len[TOpenArray: openArray | varargs](x: TOpenArray): int {...}{.
        magic: "LengthOpenArray", noSideEffect.}

  Returns the length of an openArray.

      var s = [1, 1, 1, 1, 1]
      echo len(s) # => 5

  Source Edit

    proc len(x: string): int {...}{.magic: "LengthStr", noSideEffect.}

  Returns the length of a string.

      var str = "Hello world!"
      echo len(str) # => 12

  Source Edit

    proc len(x: cstring): int {...}{.magic: "LengthStr", noSideEffect.}

  Returns the length of a compatible string. This is sometimes an O(n) operation.

      var str: cstring = "Hello world!"
      len(str) # => 12

  Source Edit

    proc len(x: (type array) | array): int {...}{.magic: "LengthArray", noSideEffect.}

  Returns the length of an array or an array type. This is roughly the same as `high(T)-low(T)+1`.

      var arr = [1, 1, 1, 1, 1]
      echo len(arr) # => 5
      echo len(array[3..8, int]) # => 6

  Source Edit

    proc len[T](x: seq[T]): int {...}{.magic: "LengthSeq", noSideEffect.}

  Returns the length of a sequence.

      var s = @[1, 1, 1, 1, 1]
      echo len(s) # => 5

  Source Edit

    proc incl[T](x: var set[T]; y: T) {...}{.magic: "Incl", noSideEffect.}

  Includes element `y` in the set `x`.

  This is the same as `x = x + {y}`, but it might be more efficient.

      var a = {1, 3, 5}
      a.incl(2) # a <- {1, 2, 3, 5}
      a.incl(4) # a <- {1, 2, 3, 4, 5}

  Source Edit

    proc excl[T](x: var set[T]; y: T) {...}{.magic: "Excl", noSideEffect.}

  Excludes element `y` from the set `x`.

  This is the same as `x = x - {y}`, but it might be more efficient.

      var b = {2, 3, 5, 6, 12, 545}
      b.excl(5)  # b <- {2, 3, 6, 12, 545}

  Source Edit

    proc card[T](x: set[T]): int {...}{.magic: "Card", noSideEffect.}

  Returns the cardinality of the set `x`, i.e. the number of elements in the set.

      var a = {1, 3, 5, 7}
      echo card(a) # => 4

  Source Edit

    proc len[T](x: set[T]): int {...}{.magic: "Card", noSideEffect.}

  An alias for `card(x)`. Source Edit

    proc ord[T: Ordinal | enum](x: T): int {...}{.magic: "Ord", noSideEffect.}

  Returns the internal `int` value of an ordinal value `x`.

      echo ord('A') # => 65
      echo ord('a') # => 97

  Source Edit

    proc chr(u: range[0 .. 255]): char {...}{.magic: "Chr", noSideEffect.}

  Converts an `int` in the range `0..255` to a character.

      echo chr(65) # => A
      echo chr(97) # => a

  Source Edit

    proc ze(x: int8): int {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int`. This treats `x` as unsigned. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc ze(x: int16): int {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int`. This treats `x` as unsigned. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc ze64(x: int8): int64 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int64`. This treats `x` as unsigned. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc ze64(x: int16): int64 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int64`. This treats `x` as unsigned. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc ze64(x: int32): int64 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int64`. This treats `x` as unsigned. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc ze64(x: int): int64 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  zero extends a smaller integer type to `int64`. This treats `x` as unsigned. Does nothing if the size of an `int` is the same as `int64`. (This is the case on 64 bit processors.) Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc toU8(x: int): int8 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  treats `x` as unsigned and converts it to a byte by taking the last 8 bits from `x`. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc toU16(x: int): int16 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  treats `x` as unsigned and converts it to an `int16` by taking the last 16 bits from `x`. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc toU32(x: int64): int32 {...}{.deprecated, raises: [], tags: [].}

  Deprecated
  treats `x` as unsigned and converts it to an `int32` by taking the last 32 bits from `x`. Deprecated since version 0.19.9: Use unsigned integers instead. Source Edit

    proc `+`(x: int): int {...}{.magic: "UnaryPlusI", noSideEffect.}

  Unary `+` operator for an integer. Has no effect. Source Edit

    proc `+`(x: int8): int8 {...}{.magic: "UnaryPlusI", noSideEffect.}

  Source Edit

    proc `+`(x: int16): int16 {...}{.magic: "UnaryPlusI", noSideEffect.}

  Source Edit

    proc `+`(x: int32): int32 {...}{.magic: "UnaryPlusI", noSideEffect.}

  Source Edit

    proc `+`(x: int64): int64 {...}{.magic: "UnaryPlusI", noSideEffect.}

  Source Edit

    proc `-`(x: int): int {...}{.magic: "UnaryMinusI", noSideEffect.}

  Unary `-` operator for an integer. Negates `x`. Source Edit

    proc `-`(x: int8): int8 {...}{.magic: "UnaryMinusI", noSideEffect.}

  Source Edit

    proc `-`(x: int16): int16 {...}{.magic: "UnaryMinusI", noSideEffect.}

  Source Edit

    proc `-`(x: int32): int32 {...}{.magic: "UnaryMinusI", noSideEffect.}

  Source Edit

    proc `-`(x: int64): int64 {...}{.magic: "UnaryMinusI64", noSideEffect.}

  Source Edit

    proc `not`(x: int): int {...}{.magic: "BitnotI", noSideEffect.}

  Computes the `bitwise complement` of the integer `x`.

      var
        a = 0'u8
        b = 0'i8
        c = 1000'u16
        d = 1000'i16

      echo not a # => 255
      echo not b # => -1
      echo not c # => 64535
      echo not d # => -1001

  Source Edit

    proc `not`(x: int8): int8 {...}{.magic: "BitnotI", noSideEffect.}

  Source Edit

    proc `not`(x: int16): int16 {...}{.magic: "BitnotI", noSideEffect.}

  Source Edit

    proc `not`(x: int32): int32 {...}{.magic: "BitnotI", noSideEffect.}

  Source Edit

    proc `not`(x: int64): int64 {...}{.magic: "BitnotI", noSideEffect.}

  Source Edit

    proc `+`(x, y: int): int {...}{.magic: "AddI", noSideEffect.}

  Binary `+` operator for an integer. Source Edit

    proc `+`(x, y: int8): int8 {...}{.magic: "AddI", noSideEffect.}

  Source Edit

    proc `+`(x, y: int16): int16 {...}{.magic: "AddI", noSideEffect.}

  Source Edit

    proc `+`(x, y: int32): int32 {...}{.magic: "AddI", noSideEffect.}

  Source Edit

    proc `+`(x, y: int64): int64 {...}{.magic: "AddI", noSideEffect.}

  Source Edit

    proc `-`(x, y: int): int {...}{.magic: "SubI", noSideEffect.}

  Binary `-` operator for an integer. Source Edit

    proc `-`(x, y: int8): int8 {...}{.magic: "SubI", noSideEffect.}

  Source Edit

    proc `-`(x, y: int16): int16 {...}{.magic: "SubI", noSideEffect.}

  Source Edit

    proc `-`(x, y: int32): int32 {...}{.magic: "SubI", noSideEffect.}

  Source Edit

    proc `-`(x, y: int64): int64 {...}{.magic: "SubI", noSideEffect.}

  Source Edit

    proc `*`(x, y: int): int {...}{.magic: "MulI", noSideEffect.}

  Binary `*` operator for an integer. Source Edit

    proc `*`(x, y: int8): int8 {...}{.magic: "MulI", noSideEffect.}

  Source Edit

    proc `*`(x, y: int16): int16 {...}{.magic: "MulI", noSideEffect.}

  Source Edit

    proc `*`(x, y: int32): int32 {...}{.magic: "MulI", noSideEffect.}

  Source Edit

    proc `*`(x, y: int64): int64 {...}{.magic: "MulI", noSideEffect.}

  Source Edit

    proc `div`(x, y: int): int {...}{.magic: "DivI", noSideEffect.}

  Computes the integer division.

  This is roughly the same as `trunc(x/y)`.

      ( 1 div  2) ==  0
      ( 2 div  2) ==  1
      ( 3 div  2) ==  1
      ( 7 div  3) ==  2
      (-7 div  3) == -2
      ( 7 div -3) == -2
      (-7 div -3) ==  2

  Source Edit

    proc `div`(x, y: int8): int8 {...}{.magic: "DivI", noSideEffect.}

  Source Edit

    proc `div`(x, y: int16): int16 {...}{.magic: "DivI", noSideEffect.}

  Source Edit

    proc `div`(x, y: int32): int32 {...}{.magic: "DivI", noSideEffect.}

  Source Edit

    proc `div`(x, y: int64): int64 {...}{.magic: "DivI", noSideEffect.}

  Source Edit

    proc `mod`(x, y: int): int {...}{.magic: "ModI", noSideEffect.}

  Computes the integer modulo operation (remainder).

  This is the same as `x - (x div y) * y`.

      ( 7 mod  5) ==  2
      (-7 mod  5) == -2
      ( 7 mod -5) ==  2
      (-7 mod -5) == -2

  Source Edit

    proc `mod`(x, y: int8): int8 {...}{.magic: "ModI", noSideEffect.}

  Source Edit

    proc `mod`(x, y: int16): int16 {...}{.magic: "ModI", noSideEffect.}

  Source Edit

    proc `mod`(x, y: int32): int32 {...}{.magic: "ModI", noSideEffect.}

  Source Edit

    proc `mod`(x, y: int64): int64 {...}{.magic: "ModI", noSideEffect.}

  Source Edit

    proc `shr`(x: int; y: SomeInteger): int {...}{.magic: "AshrI", noSideEffect.}

  Computes the `shift right` operation of `x` and `y`, filling vacant bit positions with the sign bit.

  Note: Operator precedence is different than in C.

  See also:

  - ashr proc for arithmetic shift right

      0b0001_0000'i8 shr 2 == 0b0000_0100'i8
      0b0000_0001'i8 shr 1 == 0b0000_0000'i8
      0b1000_0000'i8 shr 4 == 0b1111_1000'i8
      -1 shr 5 == -1
      1 shr 5 == 0
      16 shr 2 == 4
      -16 shr 2 == -4

  Source Edit

    proc `shr`(x: int8; y: SomeInteger): int8 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc `shr`(x: int16; y: SomeInteger): int16 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc `shr`(x: int32; y: SomeInteger): int32 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc `shr`(x: int64; y: SomeInteger): int64 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc `shl`(x: int; y: SomeInteger): int {...}{.magic: "ShlI", noSideEffect.}

  Computes the `shift left` operation of `x` and `y`.

  Note: Operator precedence is different than in C.

      1'i32 shl 4 == 0x0000_0010
      1'i64 shl 4 == 0x0000_0000_0000_0010

  Source Edit

    proc `shl`(x: int8; y: SomeInteger): int8 {...}{.magic: "ShlI", noSideEffect.}

  Source Edit

    proc `shl`(x: int16; y: SomeInteger): int16 {...}{.magic: "ShlI", noSideEffect.}

  Source Edit

    proc `shl`(x: int32; y: SomeInteger): int32 {...}{.magic: "ShlI", noSideEffect.}

  Source Edit

    proc `shl`(x: int64; y: SomeInteger): int64 {...}{.magic: "ShlI", noSideEffect.}

  Source Edit

    proc ashr(x: int; y: SomeInteger): int {...}{.magic: "AshrI", noSideEffect.}

  Shifts right by pushing copies of the leftmost bit in from the left, and let the rightmost bits fall off.

  Note that `ashr` is not an operator so use the normal function call syntax for it.

  See also:

  - shr proc

      ashr(0b0001_0000'i8, 2) == 0b0000_0100'i8
      ashr(0b1000_0000'i8, 8) == 0b1111_1111'i8
      ashr(0b1000_0000'i8, 1) == 0b1100_0000'i8

  Source Edit

    proc ashr(x: int8; y: SomeInteger): int8 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc ashr(x: int16; y: SomeInteger): int16 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc ashr(x: int32; y: SomeInteger): int32 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc ashr(x: int64; y: SomeInteger): int64 {...}{.magic: "AshrI", noSideEffect.}

  Source Edit

    proc `and`(x, y: int): int {...}{.magic: "BitandI", noSideEffect.}

  Computes the `bitwise and` of numbers `x` and `y`.

      (0b0011 and 0b0101) == 0b0001
      (0b0111 and 0b1100) == 0b0100

  Source Edit

    proc `and`(x, y: int8): int8 {...}{.magic: "BitandI", noSideEffect.}

  Source Edit

    proc `and`(x, y: int16): int16 {...}{.magic: "BitandI", noSideEffect.}

  Source Edit

    proc `and`(x, y: int32): int32 {...}{.magic: "BitandI", noSideEffect.}

  Source Edit

    proc `and`(x, y: int64): int64 {...}{.magic: "BitandI", noSideEffect.}

  Source Edit

    proc `or`(x, y: int): int {...}{.magic: "BitorI", noSideEffect.}

  Computes the `bitwise or` of numbers `x` and `y`.

      (0b0011 or 0b0101) == 0b0111
      (0b0111 or 0b1100) == 0b1111

  Source Edit

    proc `or`(x, y: int8): int8 {...}{.magic: "BitorI", noSideEffect.}

  Source Edit

    proc `or`(x, y: int16): int16 {...}{.magic: "BitorI", noSideEffect.}

  Source Edit

    proc `or`(x, y: int32): int32 {...}{.magic: "BitorI", noSideEffect.}

  Source Edit

    proc `or`(x, y: int64): int64 {...}{.magic: "BitorI", noSideEffect.}

  Source Edit

    proc `xor`(x, y: int): int {...}{.magic: "BitxorI", noSideEffect.}

  Computes the `bitwise xor` of numbers `x` and `y`.

      (0b0011 xor 0b0101) == 0b0110
      (0b0111 xor 0b1100) == 0b1011

  Source Edit

    proc `xor`(x, y: int8): int8 {...}{.magic: "BitxorI", noSideEffect.}

  Source Edit

    proc `xor`(x, y: int16): int16 {...}{.magic: "BitxorI", noSideEffect.}

  Source Edit

    proc `xor`(x, y: int32): int32 {...}{.magic: "BitxorI", noSideEffect.}

  Source Edit

    proc `xor`(x, y: int64): int64 {...}{.magic: "BitxorI", noSideEffect.}

  Source Edit

    proc `==`(x, y: int): bool {...}{.magic: "EqI", noSideEffect.}

  Compares two integers for equality. Source Edit

    proc `==`(x, y: int8): bool {...}{.magic: "EqI", noSideEffect.}

  Source Edit

    proc `==`(x, y: int16): bool {...}{.magic: "EqI", noSideEffect.}

  Source Edit

    proc `==`(x, y: int32): bool {...}{.magic: "EqI", noSideEffect.}

  Source Edit

    proc `==`(x, y: int64): bool {...}{.magic: "EqI", noSideEffect.}

  Source Edit

    proc `<=`(x, y: int): bool {...}{.magic: "LeI", noSideEffect.}

  Returns true if `x` is less than or equal to `y`. Source Edit

    proc `<=`(x, y: int8): bool {...}{.magic: "LeI", noSideEffect.}

  Source Edit

    proc `<=`(x, y: int16): bool {...}{.magic: "LeI", noSideEffect.}

  Source Edit

    proc `<=`(x, y: int32): bool {...}{.magic: "LeI", noSideEffect.}

  Source Edit

    proc `<=`(x, y: int64): bool {...}{.magic: "LeI", noSideEffect.}

  Source Edit

    proc `<`(x, y: int): bool {...}{.magic: "LtI", noSideEffect.}

  Returns true if `x` is less than `y`. Source Edit

    proc `<`(x, y: int8): bool {...}{.magic: "LtI", noSideEffect.}

  Source Edit

    proc `<`(x, y: int16): bool {...}{.magic: "LtI", noSideEffect.}

  Source Edit

    proc `<`(x, y: int32): bool {...}{.magic: "LtI", noSideEffect.}

  Source Edit

    proc `<`(x, y: int64): bool {...}{.magic: "LtI", noSideEffect.}

  Source Edit

    proc `+%`(x, y: IntMax32): IntMax32 {...}{.magic: "AddU", noSideEffect.}

  Source Edit

    proc `+%`(x, y: int64): int64 {...}{.magic: "AddU", noSideEffect.}

  Treats `x` and `y` as unsigned and adds them.

  The result is truncated to fit into the result. This implements modulo arithmetic. No overflow errors are possible.

  Source Edit

    proc `-%`(x, y: IntMax32): IntMax32 {...}{.magic: "SubU", noSideEffect.}

  Source Edit

    proc `-%`(x, y: int64): int64 {...}{.magic: "SubU", noSideEffect.}

  Treats `x` and `y` as unsigned and subtracts them.

  The result is truncated to fit into the result. This implements modulo arithmetic. No overflow errors are possible.

  Source Edit

    proc `*%`(x, y: IntMax32): IntMax32 {...}{.magic: "MulU", noSideEffect.}

  Source Edit

    proc `*%`(x, y: int64): int64 {...}{.magic: "MulU", noSideEffect.}

  Treats `x` and `y` as unsigned and multiplies them.

  The result is truncated to fit into the result. This implements modulo arithmetic. No overflow errors are possible.

  Source Edit

    proc `/%`(x, y: IntMax32): IntMax32 {...}{.magic: "DivU", noSideEffect.}

  Source Edit

    proc `/%`(x, y: int64): int64 {...}{.magic: "DivU", noSideEffect.}

  Treats `x` and `y` as unsigned and divides them.

  The result is truncated to fit into the result. This implements modulo arithmetic. No overflow errors are possible.

  Source Edit

    proc `%%`(x, y: IntMax32): IntMax32 {...}{.magic: "ModU", noSideEffect.}

  Source Edit

    proc `%%`(x, y: int64): int64 {...}{.magic: "ModU", noSideEffect.}

  Treats `x` and `y` as unsigned and compute the modulo of `x` and `y`.

  The result is truncated to fit into the result. This implements modulo arithmetic. No overflow errors are possible.

  Source Edit

    proc `<=%`(x, y: IntMax32): bool {...}{.magic: "LeU", noSideEffect.}

  Source Edit

    proc `<=%`(x, y: int64): bool {...}{.magic: "LeU64", noSideEffect.}

  Treats `x` and `y` as unsigned and compares them. Returns true if `unsigned(x) <= unsigned(y)`. Source Edit

    proc `<%`(x, y: IntMax32): bool {...}{.magic: "LtU", noSideEffect.}

  Source Edit

    proc `<%`(x, y: int64): bool {...}{.magic: "LtU64", noSideEffect.}

  Treats `x` and `y` as unsigned and compares them. Returns true if `unsigned(x) < unsigned(y)`. Source Edit

    proc `not`[T: SomeUnsignedInt](x: T): T {...}{.magic: "BitnotI", noSideEffect.}

  Computes the `bitwise complement` of the integer `x`. Source Edit

    proc `shr`[T: SomeUnsignedInt](x: T; y: SomeInteger): T {...}{.magic: "ShrI", noSideEffect.}

  Computes the `shift right` operation of `x` and `y`. Source Edit

    proc `shl`[T: SomeUnsignedInt](x: T; y: SomeInteger): T {...}{.magic: "ShlI", noSideEffect.}

  Computes the `shift left` operation of `x` and `y`. Source Edit

    proc `and`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "BitandI", noSideEffect.}

  Computes the `bitwise and` of numbers `x` and `y`. Source Edit

    proc `or`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "BitorI", noSideEffect.}

  Computes the `bitwise or` of numbers `x` and `y`. Source Edit

    proc `xor`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "BitxorI", noSideEffect.}

  Computes the `bitwise xor` of numbers `x` and `y`. Source Edit

    proc `==`[T: SomeUnsignedInt](x, y: T): bool {...}{.magic: "EqI", noSideEffect.}

  Compares two unsigned integers for equality. Source Edit

    proc `+`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "AddU", noSideEffect.}

  Binary `+` operator for unsigned integers. Source Edit

    proc `-`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "SubU", noSideEffect.}

  Binary `-` operator for unsigned integers. Source Edit

    proc `*`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "MulU", noSideEffect.}

  Binary `*` operator for unsigned integers. Source Edit

    proc `div`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "DivU", noSideEffect.}

  Computes the integer division for unsigned integers. This is roughly the same as `trunc(x/y)`. Source Edit

    proc `mod`[T: SomeUnsignedInt](x, y: T): T {...}{.magic: "ModU", noSideEffect.}

  Computes the integer modulo operation (remainder) for unsigned integers. This is the same as `x - (x div y) * y`. Source Edit

    proc `<=`[T: SomeUnsignedInt](x, y: T): bool {...}{.magic: "LeU", noSideEffect.}

  Returns true if `x <= y`. Source Edit

    proc `<`[T: SomeUnsignedInt](x, y: T): bool {...}{.magic: "LtU", noSideEffect.}

  Returns true if `unsigned(x) < unsigned(y)`. Source Edit

    proc `+`(x: float32): float32 {...}{.magic: "UnaryPlusF64", noSideEffect.}

  Source Edit

    proc `-`(x: float32): float32 {...}{.magic: "UnaryMinusF64", noSideEffect.}

  Source Edit

    proc `+`(x, y: float32): float32 {...}{.magic: "AddF64", noSideEffect.}

  Source Edit

    proc `-`(x, y: float32): float32 {...}{.magic: "SubF64", noSideEffect.}

  Source Edit

    proc `*`(x, y: float32): float32 {...}{.magic: "MulF64", noSideEffect.}

  Source Edit

    proc `/`(x, y: float32): float32 {...}{.magic: "DivF64", noSideEffect.}

  Source Edit

    proc `+`(x: float): float {...}{.magic: "UnaryPlusF64", noSideEffect.}

  Source Edit

    proc `-`(x: float): float {...}{.magic: "UnaryMinusF64", noSideEffect.}

  Source Edit

    proc `+`(x, y: float): float {...}{.magic: "AddF64", noSideEffect.}

  Source Edit

    proc `-`(x, y: float): float {...}{.magic: "SubF64", noSideEffect.}

  Source Edit

    proc `*`(x, y: float): float {...}{.magic: "MulF64", noSideEffect.}

  Source Edit

    proc `/`(x, y: float): float {...}{.magic: "DivF64", noSideEffect.}

  Source Edit

    proc `==`(x, y: float32): bool {...}{.magic: "EqF64", noSideEffect.}

  Source Edit

    proc `<=`(x, y: float32): bool {...}{.magic: "LeF64", noSideEffect.}

  Source Edit

    proc `<`(x, y: float32): bool {...}{.magic: "LtF64", noSideEffect.}

  Source Edit

    proc `==`(x, y: float): bool {...}{.magic: "EqF64", noSideEffect.}

  Source Edit

    proc `<=`(x, y: float): bool {...}{.magic: "LeF64", noSideEffect.}

  Source Edit

    proc `<`(x, y: float): bool {...}{.magic: "LtF64", noSideEffect.}

  Source Edit

    proc `*`[T](x, y: set[T]): set[T] {...}{.magic: "MulSet", noSideEffect.}

  This operator computes the intersection of two sets.

      let
        a = {1, 2, 3}
        b = {2, 3, 4}
      echo a * b # => {2, 3}

  Source Edit

    proc `+`[T](x, y: set[T]): set[T] {...}{.magic: "PlusSet", noSideEffect.}

  This operator computes the union of two sets.

      let
        a = {1, 2, 3}
        b = {2, 3, 4}
      echo a + b # => {1, 2, 3, 4}

  Source Edit

    proc `-`[T](x, y: set[T]): set[T] {...}{.magic: "MinusSet", noSideEffect.}

  This operator computes the diference of two sets.

      let
        a = {1, 2, 3}
        b = {2, 3, 4}
      echo a - b # => {1}

  Source Edit

    proc contains[T](x: set[T]; y: T): bool {...}{.magic: "InSet", noSideEffect.}

  One should overload this proc if one wants to overload the `in` operator.

  The parameters are in reverse order! `a in b` is a template for `contains(b, a)`. This is because the unification algorithm that Nim uses for overload resolution works from left to right. But for the `in` operator that would be the wrong direction for this piece of code:

      var s: set[range['a'..'z']] = {'a'..'c'}
      assert s.contains('c')
      assert 'b' in s

  If `in` had been declared as `[T](elem: T, s: set[T])` then `T` would have been bound to `char`. But `s` is not compatible to type `set[char]`! The solution is to bind `T` to `range['a'..'z']`. This is achieved by reversing the parameters for `contains`; `in` then passes its arguments in reverse order.

  Source Edit

    proc contains[U, V, W](s: HSlice[U, V]; value: W): bool {...}{.noSideEffect, inline.}

  Checks if `value` is within the range of `s`; returns true if `value >= s.a and value <= s.b`

      assert((1..3).contains(1) == true)
      assert((1..3).contains(2) == true)
      assert((1..3).contains(4) == false)

  Source Edit

    proc `is`[T, S](x: T; y: S): bool {...}{.magic: "Is", noSideEffect.}

  Checks if `T` is of the same type as `S`.

  For a negated version, use isnot.

      assert 42 is int
      assert @[1, 2] is seq

      proc test[T](a: T): int =
        when (T is int):
          return a
        else:
          return 0

      assert(test[int](3) == 3)
      assert(test[string]("xyz") == 0)

  Source Edit

    proc new[T](a: var ref T) {...}{.magic: "New", noSideEffect.}

  Creates a new object of type `T` and returns a safe (traced) reference to it in `a`. Source Edit

    proc new(t: typedesc): auto

  Creates a new object of type `T` and returns a safe (traced) reference to it as result value.

  When `T` is a ref type then the resulting type will be `T`, otherwise it will be `ref T`.

  Source Edit

    proc `of`[T, S](x: typedesc[T]; y: typedesc[S]): bool {...}{.magic: "Of", noSideEffect.}

  Source Edit

    proc `of`[T, S](x: T; y: typedesc[S]): bool {...}{.magic: "Of", noSideEffect.}

  Source Edit

    proc `of`[T, S](x: T; y: S): bool {...}{.magic: "Of", noSideEffect.}

  Checks if `x` has a type of `y`.

      assert(FloatingPointError of Exception)
      assert(DivByZeroError of Exception)

  Source Edit

    proc cmp[T](x, y: T): int {...}{.procvar.}

  Generic compare proc.

  Returns:

  - a value less than zero, if `x < y`
  - a value greater than zero, if `x > y`
  - zero, if `x == y`

  This is useful for writing generic algorithms without performance loss. This generic implementation uses the `==` and `<` operators.

      import algorithm
      echo sorted(@[4, 2, 6, 5, 8, 7], cmp[int])

  Source Edit

    proc `@`[IDX, T](a: sink array[IDX, T]): seq[T] {...}{.magic: "ArrToSeq", noSideEffect.}

  Turns an array into a sequence.

  This most often useful for constructing sequences with the array constructor: `@[1, 2, 3]` has the type `seq[int]`, while `[1, 2, 3]` has the type `array[0..2, int]`.

      let
        a = [1, 3, 5]
        b = "foo"

      echo @a # => @[1, 3, 5]
      echo @b # => @['f', 'o', 'o']

  Source Edit

    proc default(T: typedesc): T:type {...}{.magic: "Default", noSideEffect.}

  returns the default value of the type `T`. Source Edit

    proc setLen[T](s: var seq[T]; newlen: Natural) {...}{.magic: "SetLengthSeq", noSideEffect.}

  Sets the length of seq `s` to `newlen`. `T` may be any sequence type.

  If the current length is greater than the new length, `s` will be truncated.

      var x = @[10, 20]
      x.setLen(5)
      x[4] = 50
      assert x == @[10, 20, 0, 0, 50]
      x.setLen(1)
      assert x == @[10]

  Source Edit

    proc setLen(s: var string; newlen: Natural) {...}{.magic: "SetLengthStr", noSideEffect.}

  Sets the length of string `s` to `newlen`.

  If the current length is greater than the new length, `s` will be truncated.

      var myS = "Nim is great!!"
      myS.setLen(3) # myS <- "Nim"
      echo myS, " is fantastic!!"

  Source Edit

    proc newString(len: Natural): string {...}{.magic: "NewString", importc: "mnewString",
                                       noSideEffect.}

  Returns a new string of length `len` but with uninitialized content. One needs to fill the string character after character with the index operator `s[i]`.

  This procedure exists only for optimization purposes; the same effect can be achieved with the `&` operator or with `add`.

  Source Edit

    proc newStringOfCap(cap: Natural): string {...}{.magic: "NewStringOfCap",
                                            importc: "rawNewString", noSideEffect.}

  Returns a new string of length `0` but with capacity `cap`.

  This procedure exists only for optimization purposes; the same effect can be achieved with the `&` operator or with `add`.

  Source Edit

    proc `&`(x: string; y: char): string {...}{.magic: "ConStrStr", noSideEffect, merge.}

  Concatenates `x` with `y`.

      assert("ab" & 'c' == "abc")

  Source Edit

    proc `&`(x, y: char): string {...}{.magic: "ConStrStr", noSideEffect, merge.}

  Concatenates characters `x` and `y` into a string.

      assert('a' & 'b' == "ab")

  Source Edit

    proc `&`(x, y: string): string {...}{.magic: "ConStrStr", noSideEffect, merge.}

  Concatenates strings `x` and `y`.

      assert("ab" & "cd" == "abcd")

  Source Edit

    proc `&`(x: char; y: string): string {...}{.magic: "ConStrStr", noSideEffect, merge.}

  Concatenates `x` with `y`.

      assert('a' & "bc" == "abc")

  Source Edit

    proc add(x: var string; y: char) {...}{.magic: "AppendStrCh", noSideEffect.}

  Appends `y` to `x` in place.

      var tmp = ""
      tmp.add('a')
      tmp.add('b')
      assert(tmp == "ab")

  Source Edit

    proc add(x: var string; y: string) {...}{.magic: "AppendStrStr", noSideEffect.}

  Concatenates `x` and `y` in place.

      var tmp = ""
      tmp.add("ab")
      tmp.add("cd")
      assert(tmp == "abcd")

  Source Edit

    proc compileOption(option: string): bool {...}{.magic: "CompileOption", noSideEffect.}

  Can be used to determine an `on|off` compile-time option. Example:

      when compileOption("floatchecks"):
        echo "compiled with floating point NaN and Inf checks"

  Source Edit

    proc compileOption(option, arg: string): bool {...}{.magic: "CompileOptionArg", noSideEffect.}

  Can be used to determine an enum compile-time option. Example:

      when compileOption("opt", "size") and compileOption("gc", "boehm"):
        echo "compiled with optimization for size and uses Boehm's GC"

  Source Edit

    proc quit(errorcode: int = QuitSuccess) {...}{.magic: "Exit", noreturn.}

  Stops the program immediately with an exit code.

  Before stopping the program the "quit procedures" are called in the opposite order they were added with addQuitProc. `quit` never returns and ignores any exception that may have been raised by the quit procedures. It does not call the garbage collector to free all the memory, unless a quit procedure calls GC_fullCollect.

  The proc `quit(QuitSuccess)` is called implicitly when your nim program finishes without incident for platforms where this is the expected behavior. A raised unhandled exception is equivalent to calling `quit(QuitFailure)`.

  Note that this is a runtime call and using `quit` inside a macro won't have any compile time effect. If you need to stop the compiler inside a macro, use the error or fatal pragmas.

  Source Edit

    proc add[T](x: var seq[T]; y: T) {...}{.magic: "AppendSeqElem", noSideEffect.}

  Generic proc for adding a data item `y` to a container `x`.

  For containers that have an order, `add` means append. New generic containers should also call their adding proc `add` for consistency. Generic code becomes much easier to write if the Nim naming scheme is respected.

  Source Edit

    proc add[T](x: var seq[T]; y: openArray[T]) {...}{.noSideEffect.}

  Generic proc for adding a container `y` to a container `x`.

  For containers that have an order, `add` means append. New generic containers should also call their adding proc `add` for consistency. Generic code becomes much easier to write if the Nim naming scheme is respected.

  See also:

  - & proc

      var s: seq[string] = @["test2","test2"]
      s.add("test") # s <- @[test2, test2, test]

  Source Edit

    proc del[T](x: var seq[T]; i: Natural) {...}{.noSideEffect.}

  Deletes the item at index `i` by putting `x[high(x)]` into position `i`.

  This is an `O(1)` operation.

  See also:

  - delete for preserving the order

      var i = @[1, 2, 3, 4, 5]
      i.del(2) # => @[1, 2, 5, 4]

  Source Edit

    proc delete[T](x: var seq[T]; i: Natural) {...}{.noSideEffect.}

  Deletes the item at index `i` by moving all `x[i+1..]` items by one position.

  This is an `O(n)` operation.

  See also:

  - del for O(1) operation

      var i = @[1, 2, 3, 4, 5]
      i.delete(2) # => @[1, 2, 4, 5]

  Source Edit

    proc insert[T](x: var seq[T]; item: T; i = 0.Natural) {...}{.noSideEffect.}

  Inserts `item` into `x` at position `i`.

      var i = @[1, 3, 5]
      i.insert(99, 0) # i <- @[99, 1, 3, 5]

  Source Edit

    proc repr[T](x: T): string {...}{.magic: "Repr", noSideEffect.}

  Takes any Nim variable and returns its string representation.

  It works even for complex data graphs with cycles. This is a great debugging tool.

      var s: seq[string] = @["test2", "test2"]
      var i = @[1, 2, 3, 4, 5]
      echo repr(s) # => 0x1055eb050[0x1055ec050"test2", 0x1055ec078"test2"]
      echo repr(i) # => 0x1055ed050[1, 2, 3, 4, 5]

  Source Edit

    proc toFloat(i: int): float {...}{.noSideEffect, inline, raises: [], tags: [].}

  Converts an integer `i` into a `float`.

  If the conversion fails, `ValueError` is raised. However, on most platforms the conversion cannot fail.

      let
        a = 2
        b = 3.7

      echo a.toFloat + b # => 5.7

  Source Edit

    proc toBiggestFloat(i: BiggestInt): BiggestFloat {...}{.noSideEffect, inline, raises: [],
        tags: [].}

  Same as toFloat but for `BiggestInt` to `BiggestFloat`. Source Edit

    proc toInt(f: float): int {...}{.noSideEffect, raises: [], tags: [].}

  Converts a floating point number `f` into an `int`.

  Conversion rounds `f` half away from 0, see Round half away from zero.

  Note that some floating point numbers (e.g. infinity or even 1e19) cannot be accurately converted.

      doAssert toInt(0.49) == 0
      doAssert toInt(0.5) == 1
      doAssert toInt(-0.5) == -1 # rounding is symmetrical

  Source Edit

    proc toBiggestInt(f: BiggestFloat): BiggestInt {...}{.noSideEffect, raises: [], tags: [].}

  Same as toInt but for `BiggestFloat` to `BiggestInt`. Source Edit

    proc addQuitProc(quitProc: proc () {...}{.noconv.}) {...}{.importc: "atexit",
        header: "<stdlib.h>".}

  Adds/registers a quit procedure.

  Each call to `addQuitProc` registers another quit procedure. Up to 30 procedures can be registered. They are executed on a last-in, first-out basis (that is, the last function registered is the first to be executed). `addQuitProc` raises an EOutOfIndex exception if `quitProc` cannot be registered.

  Source Edit

    proc createU(T: typedesc; size = 1.Positive): ptr T:type {...}{.inline, gcsafe, locks: 0,
        raises: [].}

  Allocates a new memory block with at least `T.sizeof * size` bytes.

  The block has to be freed with resize(block, 0) or dealloc(block). The block is not initialized, so reading from it before writing to it is undefined behaviour!

  The allocated memory belongs to its allocating thread! Use createSharedU to allocate from a shared heap.

  See also:

  - create
  Source Edit

    proc create(T: typedesc; size = 1.Positive): ptr T:type {...}{.inline, gcsafe, locks: 0,
        raises: [].}

  Allocates a new memory block with at least `T.sizeof * size` bytes.

  The block has to be freed with resize(block, 0) or dealloc(block). The block is initialized with all bytes containing zero, so it is somewhat safer than createU.

  The allocated memory belongs to its allocating thread! Use createShared to allocate from a shared heap.

  Source Edit

    proc resize[T](p: ptr T; newSize: Natural): ptr T {...}{.inline, gcsafe, locks: 0, raises: [].}

  Grows or shrinks a given memory block.

  If `p` is nil then a new memory block is returned. In either way the block has at least `T.sizeof * newSize` bytes. If `newSize == 0` and `p` is not nil `resize` calls `dealloc(p)`. In other cases the block has to be freed with `free`.

  The allocated memory belongs to its allocating thread! Use resizeShared to reallocate from a shared heap.

  Source Edit

    proc createSharedU(T: typedesc; size = 1.Positive): ptr T:type {...}{.inline, gcsafe, locks: 0,
        raises: [].}

  Allocates a new memory block on the shared heap with at least `T.sizeof * size` bytes.

  The block has to be freed with resizeShared(block, 0) or freeShared(block).

  The block is not initialized, so reading from it before writing to it is undefined behaviour!

  See also:

  - createShared
  Source Edit

    proc createShared(T: typedesc; size = 1.Positive): ptr T:type {...}{.inline.}

  Allocates a new memory block on the shared heap with at least `T.sizeof * size` bytes.

  The block has to be freed with resizeShared(block, 0) or freeShared(block).

  The block is initialized with all bytes containing zero, so it is somewhat safer than createSharedU.

  Source Edit

    proc resizeShared[T](p: ptr T; newSize: Natural): ptr T {...}{.inline, raises: [].}

  Grows or shrinks a given memory block on the heap.

  If `p` is nil then a new memory block is returned. In either way the block has at least `T.sizeof * newSize` bytes. If `newSize == 0` and `p` is not nil `resizeShared` calls `freeShared(p)`. In other cases the block has to be freed with freeShared.

  Source Edit

    proc freeShared[T](p: ptr T) {...}{.inline, gcsafe, locks: 0, raises: [].}

  Frees the memory allocated with `createShared`, `createSharedU` or `resizeShared`.

  This procedure is dangerous! If one forgets to free the memory a leak occurs; if one tries to access freed memory (or just freeing it twice!) a core dump may happen or other memory may be corrupted.

  Source Edit

    proc swap[T](a, b: var T) {...}{.magic: "Swap", noSideEffect.}

  Swaps the values `a` and `b`.

  This is often more efficient than `tmp = a; a = b; b = tmp`. Particularly useful for sorting algorithms.

      var
        a = 5
        b = 9

      swap(a, b)

      assert a == 9
      assert b == 5

  Source Edit

    proc getRefcount[T](x: ref T): int {...}{.importc: "getRefcount", noSideEffect, deprecated: "the refcount was never reliable, the GC does not use traditional refcounting".}

  Deprecated: the refcount was never reliable, the GC does not use traditional refcounting
  Source Edit

    proc getRefcount(x: string): int {...}{.importc: "getRefcount", noSideEffect, deprecated: "the refcount was never reliable, the GC does not use traditional refcounting".}

  Deprecated: the refcount was never reliable, the GC does not use traditional refcounting
  Source Edit

    proc getRefcount[T](x: seq[T]): int {...}{.importc: "getRefcount", noSideEffect, deprecated: "the refcount was never reliable, the GC does not use traditional refcounting".}

  Deprecated: the refcount was never reliable, the GC does not use traditional refcounting

  > Retrieves the reference count of an heap-allocated object. The value is implementation-dependent.

  Source Edit

    proc `|`(a, b: typedesc): typedesc

  Source Edit

    proc min(x, y: int): int {...}{.magic: "MinI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc min(x, y: int8): int8 {...}{.magic: "MinI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc min(x, y: int16): int16 {...}{.magic: "MinI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc min(x, y: int32): int32 {...}{.magic: "MinI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc min(x, y: int64): int64 {...}{.magic: "MinI", noSideEffect, raises: [], tags: [].}

  The minimum value of two integers. Source Edit

    proc min[T](x: openArray[T]): T

  The minimum value of `x`. `T` needs to have a `<` operator. Source Edit

    proc max(x, y: int): int {...}{.magic: "MaxI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc max(x, y: int8): int8 {...}{.magic: "MaxI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc max(x, y: int16): int16 {...}{.magic: "MaxI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc max(x, y: int32): int32 {...}{.magic: "MaxI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc max(x, y: int64): int64 {...}{.magic: "MaxI", noSideEffect, raises: [], tags: [].}

  The maximum value of two integers. Source Edit

    proc max[T](x: openArray[T]): T

  The maximum value of `x`. `T` needs to have a `<` operator. Source Edit

    proc abs(x: float64): float64 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc abs(x: float32): float32 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc min(x, y: float32): float32 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc min(x, y: float64): float64 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc max(x, y: float32): float32 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc max(x, y: float64): float64 {...}{.noSideEffect, inline, raises: [], tags: [].}

  Source Edit

    proc min[T: not SomeFloat](x, y: T): T {...}{.inline.}

  Source Edit

    proc max[T: not SomeFloat](x, y: T): T {...}{.inline.}

  Source Edit

    proc high(T: typedesc[SomeFloat]): T:type

  Source Edit

    proc low(T: typedesc[SomeFloat]): T:type

  Source Edit

    proc clamp[T](x, a, b: T): T

  Limits the value `x` within the interval [a, b].

      assert((1.4).clamp(0.0, 1.0) == 1.0)
      assert((0.5).clamp(0.0, 1.0) == 0.5)

  Source Edit

    proc len[U: Ordinal; V: Ordinal](x: HSlice[U, V]): int {...}{.noSideEffect, inline.}

  Length of ordinal slice. When x.b < x.a returns zero length.

      assert((0..5).len == 6)
      assert((5..2).len == 0)

  Source Edit

    proc isNil[T](x: seq[T]): bool {...}{.noSideEffect, magic: "IsNil", error.}

  Source Edit

    proc isNil[T](x: ref T): bool {...}{.noSideEffect, magic: "IsNil".}

  Source Edit

    proc isNil(x: string): bool {...}{.noSideEffect, magic: "IsNil", error.}

  Source Edit

    proc isNil[T](x: ptr T): bool {...}{.noSideEffect, magic: "IsNil".}

  Source Edit

    proc isNil(x: pointer): bool {...}{.noSideEffect, magic: "IsNil".}

  Source Edit

    proc isNil(x: cstring): bool {...}{.noSideEffect, magic: "IsNil".}

  Source Edit

    proc isNil[T: proc](x: T): bool {...}{.noSideEffect, magic: "IsNil".}

  Fast check whether `x` is nil. This is sometimes more efficient than `== nil`. Source Edit

    proc `==`[I, T](x, y: array[I, T]): bool

  Source Edit

    proc `==`[T](x, y: openArray[T]): bool

  Source Edit

    proc `@`[T](a: openArray[T]): seq[T]

  Turns an openArray into a sequence.

  This is not as efficient as turning a fixed length array into a sequence as it always copies every element of `a`.

  Source Edit

    proc `&`[T](x, y: seq[T]): seq[T] {...}{.noSideEffect.}

  Concatenates two sequences.

  Requires copying of the sequences.

  See also:

  - add(var seq[T], openArray[T])

      assert(@[1, 2, 3, 4] & @[5, 6] == @[1, 2, 3, 4, 5, 6])

  Source Edit

    proc `&`[T](x: seq[T]; y: T): seq[T] {...}{.noSideEffect.}

  Appends element y to the end of the sequence.

  Requires copying of the sequence.

  See also:

  - add(var seq[T], T)

      assert(@[1, 2, 3] & 4 == @[1, 2, 3, 4])

  Source Edit

    proc `&`[T](x: T; y: seq[T]): seq[T] {...}{.noSideEffect.}

  Prepends the element x to the beginning of the sequence.

  Requires copying of the sequence.

      assert(1 & @[2, 3, 4] == @[1, 2, 3, 4])

  Source Edit

    proc `==`[T](x, y: seq[T]): bool {...}{.noSideEffect.}

  Generic equals operator for sequences: relies on a equals operator for the element type `T`. Source Edit

    proc astToStr[T](x: T): string {...}{.magic: "AstToStr", noSideEffect.}

  Converts the AST of `x` into a string representation. This is very useful for debugging. Source Edit

    proc instantiationInfo(index = -1; fullPaths = false): tuple[filename: string, line: int,
        column: int] {...}{.magic: "InstantiationInfo", noSideEffect.}

  Provides access to the compiler's instantiation stack line information of a template.

  While similar to the caller info of other languages, it is determined at compile time.

  This proc is mostly useful for meta programming (eg. `assert` template) to retrieve information about the current filename and line number. Example:

      import strutils

      template testException(exception, code: untyped): typed =
        try:
          let pos = instantiationInfo()
          discard(code)
          echo "Test failure at $1:$2 with '$3'" % [pos.filename,
            $pos.line, astToStr(code)]
          assert false, "A test expecting failure succeeded?"
        except exception:
          discard

      proc tester(pos: int): int =
        let
          a = @[1, 2, 3]
        result = a[pos]

      when isMainModule:
        testException(IndexError, tester(30))
        testException(IndexError, tester(1))
        # --> Test failure at example.nim:20 with 'tester(1)'

  Source Edit

    proc compiles(x: untyped): bool {...}{.magic: "Compiles", noSideEffect, compileTime,
                                  raises: [], tags: [].}

  Special compile-time procedure that checks whether `x` can be compiled without any semantic error. This can be used to check whether a type supports some operation:

      when compiles(3 + 4):
        echo "'+' for integers is available"

  Source Edit

    proc atomicInc(memLoc: var int; x: int = 1): int {...}{.inline, discardable, gcsafe, locks: 0,
        raises: [], tags: [].}

  Atomic increment of `memLoc`. Returns the value after the operation. Source Edit

    proc atomicDec(memLoc: var int; x: int = 1): int {...}{.inline, discardable, gcsafe, locks: 0,
        raises: [], tags: [].}

  Atomic decrement of `memLoc`. Returns the value after the operation. Source Edit

    proc addAndFetch(p: ptr int; val: int): int {...}{.inline, raises: [], tags: [].}

  Source Edit

    proc cas[T: bool | int | ptr](p: ptr T; oldValue, newValue: T): bool {...}{.
        importc: "__sync_bool_compare_and_swap", nodecl.}

  Source Edit

    proc cpuRelax() {...}{.inline, raises: [], tags: [].}

  Source Edit

    proc find[T, S](a: T; item: S): int {...}{.inline.}

  Returns the first index of `item` in `a` or -1 if not found. This requires appropriate `items` and `==` operations to work. Source Edit

    proc contains[T](a: openArray[T]; item: T): bool {...}{.inline.}

  Returns true if `item` is in `a` or false if not found. This is a shortcut for `find(a, item) >= 0`.

  This allows the `in` operator: `a.contains(item)` is the same as `item in a`.

      var a = @[1, 3, 5]
      assert a.contains(5)
      assert 3 in a
      assert 99 notin a

  Source Edit

    proc pop[T](s: var seq[T]): T {...}{.inline, noSideEffect.}

  Returns the last item of `s` and decreases `s.len` by one. This treats `s` as a stack and implements the common pop operation.

  Examples:

      var a = @[1, 3, 5, 7]
      let b = pop(a)
      assert b == 7
      assert a == @[1, 3, 5]

  Source Edit

    proc `==`[T: tuple |
        object](x, y: T): bool

  Generic `==` operator for tuples that is lifted from the components. of `x` and `y`. Source Edit

    proc `<=`[T: tuple](x, y: T): bool

  Generic lexicographic `<=` operator for tuples that is lifted from the components of `x` and `y`. This implementation uses `cmp`. Source Edit

    proc `<`[T: tuple](x, y: T): bool

  Generic lexicographic `<` operator for tuples that is lifted from the components of `x` and `y`. This implementation uses `cmp`. Source Edit

    proc GC_ref[T](x: ref T) {...}{.magic: "GCref", gcsafe, locks: 0.}

  Source Edit

    proc GC_ref[T](x: seq[T]) {...}{.magic: "GCref", gcsafe, locks: 0.}

  Source Edit

    proc GC_ref(x: string) {...}{.magic: "GCref", gcsafe, locks: 0.}

  Marks the object `x` as referenced, so that it will not be freed until it is unmarked via `GC_unref`. If called n-times for the same object `x`, n calls to `GC_unref` are needed to unmark `x`. Source Edit

    proc GC_unref[T](x: ref T) {...}{.magic: "GCunref", gcsafe, locks: 0.}

  Source Edit

    proc GC_unref[T](x: seq[T]) {...}{.magic: "GCunref", gcsafe, locks: 0.}

  Source Edit

    proc GC_unref(x: string) {...}{.magic: "GCunref", gcsafe, locks: 0.}

  See the documentation of GC_ref. Source Edit

    proc add(x: var string; y: cstring) {...}{.raises: [], tags: [].}

  Source Edit

    proc echo(x: varargs[typed, `$`]) {...}{.magic: "Echo", tags: [WriteIOEffect], gcsafe,
                                    locks: 0, sideEffect.}

  Writes and flushes the parameters to the standard output.

  Special built-in that takes a variable number of arguments. Each argument is converted to a string via `$`, so it works for user-defined types that have an overloaded `$` operator. It is roughly equivalent to `writeLine(stdout, x); flushFile(stdout)`, but available for the JavaScript target too.

  Unlike other IO operations this is guaranteed to be thread-safe as `echo` is very often used for debugging convenience. If you want to use `echo` inside a proc without side effects you can use debugEcho instead.

  Source Edit

    proc debugEcho(x: varargs[typed, `$`]) {...}{.magic: "Echo", noSideEffect, tags: [],
                                         raises: [].}

  Same as echo, but as a special semantic rule, `debugEcho` pretends to be free of side effects, so that it can be used for debugging routines marked as noSideEffect. Source Edit

    proc getTypeInfo[T](x: T): pointer {...}{.magic: "GetTypeInfo", gcsafe, locks: 0.}

  Get type information for `x`.

  Ordinary code should not use this, but the typeinfo module instead.

  Source Edit

    proc abs(x: int): int {...}{.magic: "AbsI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc abs(x: int8): int8 {...}{.magic: "AbsI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc abs(x: int16): int16 {...}{.magic: "AbsI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc abs(x: int32): int32 {...}{.magic: "AbsI", noSideEffect, raises: [], tags: [].}

  Source Edit

    proc abs(x: int64): int64 {...}{.magic: "AbsI", noSideEffect, raises: [], tags: [].}

  Returns the absolute value of `x`.

  If `x` is `low(x)` (that is -MININT for its type), an overflow exception is thrown (if overflow checking is turned on).

  Source Edit

    proc zeroMem(p: pointer; size: Natural) {...}{.inline, noSideEffect, tags: [], locks: 0,
                                         raises: [].}

  Overwrites the contents of the memory at `p` with the value 0.

  Exactly `size` bytes will be overwritten. Like any procedure dealing with raw memory this is unsafe.

  Source Edit

    proc copyMem(dest, source: pointer; size: Natural) {...}{.inline, gcsafe, locks: 0, tags: [],
        locks: 0, raises: [].}

  Copies the contents from the memory at `source` to the memory at `dest`. Exactly `size` bytes will be copied. The memory regions may not overlap. Like any procedure dealing with raw memory this is unsafe. Source Edit

    proc moveMem(dest, source: pointer; size: Natural) {...}{.inline, gcsafe, locks: 0, tags: [],
        locks: 0, raises: [].}

  Copies the contents from the memory at `source` to the memory at `dest`.

  Exactly `size` bytes will be copied. The memory regions may overlap, `moveMem` handles this case appropriately and is thus somewhat more safe than `copyMem`. Like any procedure dealing with raw memory this is still unsafe, though.

  Source Edit

    proc equalMem(a, b: pointer; size: Natural): bool {...}{.inline, noSideEffect, tags: [],
        locks: 0, raises: [].}

  Compares the memory blocks `a` and `b`. `size` bytes will be compared.

  If the blocks are equal, `true` is returned, `false` otherwise. Like any procedure dealing with raw memory this is unsafe.

  Source Edit

    proc cmp(x, y: string): int {...}{.noSideEffect, procvar, raises: [], tags: [].}

  Compare proc for strings. More efficient than the generic version.

  Note: The precise result values depend on the used C runtime library and can differ between operating systems!

  Source Edit

    proc cstringArrayToSeq(a: cstringArray; len: Natural): seq[string] {...}{.raises: [],
        tags: [].}

  Converts a `cstringArray` to a `seq[string]`. `a` is supposed to be of length `len`. Source Edit

    proc cstringArrayToSeq(a: cstringArray): seq[string] {...}{.raises: [], tags: [].}

  Converts a `cstringArray` to a `seq[string]`. `a` is supposed to be terminated by `nil`. Source Edit

    proc allocCStringArray(a: openArray[string]): cstringArray {...}{.raises: [], tags: [].}

  Creates a NULL terminated cstringArray from `a`. The result has to be freed with `deallocCStringArray` after it's not needed anymore. Source Edit

    proc deallocCStringArray(a: cstringArray) {...}{.raises: [], tags: [].}

  Frees a NULL terminated cstringArray. Source Edit

    proc setControlCHook(hook: proc () {...}{.noconv.}) {...}{.raises: [Exception],
        tags: [RootEffect].}

  Allows you to override the behaviour of your application when CTRL+C is pressed. Only one such hook is supported. Source Edit

    proc unsetControlCHook() {...}{.raises: [Exception], tags: [RootEffect, WriteIOEffect].}

  Reverts a call to setControlCHook. Source Edit

    proc writeStackTrace() {...}{.tags: [], gcsafe, raises: [Exception].}

  Writes the current stack trace to `stderr`. This is only works for debug builds. Since it's usually used for debugging, this is proclaimed to have no IO effect! Source Edit

    proc getStackTrace(): string {...}{.gcsafe, raises: [], tags: [].}

  Gets the current stack trace. This only works for debug builds. Source Edit

    proc getStackTrace(e: ref Exception): string {...}{.gcsafe, raises: [], tags: [].}

  Gets the stack trace associated with `e`, which is the stack that lead to the `raise` statement. This only works for debug builds. Source Edit

    proc getFrameState(): FrameState {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc setFrameState(state: FrameState) {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc getFrame(): PFrame {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc setFrame(s: PFrame) {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc getGcFrame(): GcFrame {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc popGcFrame() {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc setGcFrame(s: GcFrame) {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc pushGcFrame(s: GcFrame) {...}{.compilerproc, inline, raises: [], tags: [].}

  Source Edit

    proc stackTraceAvailable(): bool {...}{.raises: [], tags: [].}

  Source Edit

    proc getStackTraceEntries(e: ref Exception): seq[StackTraceEntry] {...}{.raises: [],
        tags: [].}

  Returns the attached stack trace to the exception `e` as a `seq`. This is not yet available for the JS backend. Source Edit

    proc getStackTraceEntries(): seq[StackTraceEntry] {...}{.raises: [], tags: [].}

  Returns the stack trace entries for the current stack trace. This is not yet available for the JS backend. Source Edit

    proc iterToProc(iter: typed; envType: typedesc; procName: untyped) {...}{.magic: "Plugin",
        compileTime.}

  Source Edit

    proc alloc(size: Natural): pointer {...}{.noconv, gcsafe, tags: [], gcsafe, locks: 0, raises: [].}

  Allocates a new memory block with at least `size` bytes.

  The block has to be freed with realloc(block, 0) or dealloc(block). The block is not initialized, so reading from it before writing to it is undefined behaviour!

  The allocated memory belongs to its allocating thread! Use allocShared to allocate from a shared heap.

  See also:

  - alloc0
  Source Edit

    proc alloc0(size: Natural): pointer {...}{.noconv, gcsafe, tags: [], gcsafe, locks: 0,
                                      raises: [].}

  Allocates a new memory block with at least `size` bytes.

  The block has to be freed with realloc(block, 0) or dealloc(block). The block is initialized with all bytes containing zero, so it is somewhat safer than alloc.

  The allocated memory belongs to its allocating thread! Use allocShared0 to allocate from a shared heap.

  Source Edit

    proc dealloc(p: pointer) {...}{.noconv, gcsafe, tags: [], gcsafe, locks: 0, raises: [].}

  Frees the memory allocated with `alloc`, `alloc0` or `realloc`.

  This procedure is dangerous! If one forgets to free the memory a leak occurs; if one tries to access freed memory (or just freeing it twice!) a core dump may happen or other memory may be corrupted.

  The freed memory must belong to its allocating thread! Use deallocShared to deallocate from a shared heap.

  Source Edit

    proc realloc(p: pointer; newSize: Natural): pointer {...}{.noconv, gcsafe, tags: [], gcsafe,
        locks: 0, raises: [].}

  Grows or shrinks a given memory block.

  If `p` is nil then a new memory block is returned. In either way the block has at least `newSize` bytes. If `newSize == 0` and `p` is not nil `realloc` calls `dealloc(p)`. In other cases the block has to be freed with dealloc(block).

  The allocated memory belongs to its allocating thread! Use reallocShared to reallocate from a shared heap.

  Source Edit

    proc getFreeMem(): int {...}{.gcsafe, raises: [], tags: [].}

  Returns the number of bytes that are owned by the process, but do not hold any meaningful data. Source Edit

    proc getTotalMem(): int {...}{.gcsafe, raises: [], tags: [].}

  Returns the number of bytes that are owned by the process. Source Edit

    proc getOccupiedMem(): int {...}{.gcsafe, raises: [], tags: [].}

  Returns the number of bytes that are owned by the process and hold data. Source Edit

    proc getMaxMem(): int {...}{.raises: [], tags: [].}

  Source Edit

    proc allocShared(size: Natural): pointer {...}{.noconv, gcsafe, gcsafe, locks: 0, raises: [],
                                           tags: [].}

  Allocates a new memory block on the shared heap with at least `size` bytes.

  The block has to be freed with reallocShared(block, 0) or deallocShared(block).

  The block is not initialized, so reading from it before writing to it is undefined behaviour!

  See also: allocShared0.

  Source Edit

    proc allocShared0(size: Natural): pointer {...}{.noconv, gcsafe, gcsafe, locks: 0, raises: [],
                                            tags: [].}

  Allocates a new memory block on the shared heap with at least `size` bytes.

  The block has to be freed with reallocShared(block, 0) or deallocShared(block).

  The block is initialized with all bytes containing zero, so it is somewhat safer than allocShared.

  Source Edit

    proc deallocShared(p: pointer) {...}{.noconv, gcsafe, gcsafe, locks: 0, raises: [], tags: [].}

  Frees the memory allocated with `allocShared`, `allocShared0` or `reallocShared`.

  This procedure is dangerous! If one forgets to free the memory a leak occurs; if one tries to access freed memory (or just freeing it twice!) a core dump may happen or other memory may be corrupted.

  Source Edit

    proc reallocShared(p: pointer; newSize: Natural): pointer {...}{.noconv, gcsafe, gcsafe,
        locks: 0, raises: [], tags: [].}

  Grows or shrinks a given memory block on the heap.

  If `p` is nil then a new memory block is returned. In either way the block has at least `newSize` bytes. If `newSize == 0` and `p` is not nil `reallocShared` calls `deallocShared(p)`. In other cases the block has to be freed with deallocShared.

  Source Edit

    proc protect(x: pointer): ForeignCell {...}{.raises: [], tags: [].}

  Source Edit

    proc dispose(x: ForeignCell) {...}{.raises: [], tags: [].}

  Source Edit

    proc isNotForeign(x: ForeignCell): bool {...}{.raises: [], tags: [].}

  returns true if 'x' belongs to the calling thread. No deep copy has to be performed then. Source Edit

    proc setupForeignThreadGc() {...}{.gcsafe, raises: [], tags: [].}

  Call this if you registered a callback that will be run from a thread not under your control. This has a cheap thread-local guard, so the GC for this thread will only be initialized once per thread, no matter how often it is called.

  This function is available only when `--threads:on` and `--tlsEmulation:off` switches are used

  Source Edit

    proc tearDownForeignThreadGc() {...}{.gcsafe, raises: [], tags: [].}

  Call this to tear down the GC, previously initialized by `setupForeignThreadGc`. If GC has not been previously initialized, or has already been torn down, the call does nothing.

  This function is available only when `--threads:on` and `--tlsEmulation:off` switches are used

  Source Edit

    proc nimGC_setStackBottom(theStackBottom: pointer) {...}{.compilerproc, noinline, gcsafe,
        locks: 0, raises: [], tags: [].}

  Expands operating GC stack range to `theStackBottom`. Does nothing if current stack bottom is already lower than `theStackBottom`. Source Edit

    proc deallocHeap(runFinalizers = true; allowGcAfterwards = true) {...}{.raises: [Exception],
        tags: [RootEffect].}

  Frees the thread local heap. Runs every finalizer if `runFinalizers` is true. If `allowGcAfterwards` is true, a minimal amount of allocation happens to ensure the GC can continue to work after the call to `deallocHeap`. Source Edit

    proc gcInvariant() {...}{.raises: [], tags: [].}

  Source Edit

    proc GC_disable() {...}{.gcsafe, inline, gcsafe, locks: 0, raises: [], tags: [].}

  Disables the GC. If called `n` times, `n` calls to `GC_enable` are needed to reactivate the GC.

  Note that in most circumstances one should only disable the mark and sweep phase with GC_disableMarkAndSweep.

  Source Edit

    proc GC_enable() {...}{.gcsafe, inline, gcsafe, locks: 0, raises: [AssertionError], tags: [].}

  Enables the GC again. Source Edit

    proc GC_enableMarkAndSweep() {...}{.gcsafe, gcsafe, locks: 0, raises: [], tags: [].}

  Source Edit

    proc GC_disableMarkAndSweep() {...}{.gcsafe, gcsafe, locks: 0, raises: [], tags: [].}

  The current implementation uses a reference counting garbage collector with a seldomly run mark and sweep phase to free cycles. The mark and sweep phase may take a long time and is not needed if the application does not create cycles. Thus the mark and sweep phase can be deactivated and activated separately from the rest of the GC. Source Edit

    proc GC_fullCollect() {...}{.gcsafe, gcsafe, locks: 0, raises: [Exception],
                          tags: [RootEffect].}

  Forces a full garbage collection pass. Ordinary code does not need to call this (and should not). Source Edit

    proc GC_getStatistics(): string {...}{.gcsafe, gcsafe, locks: 0, raises: [], tags: [].}

  Returns an informative string about the GC's activity. This may be useful for tweaking. Source Edit

    proc addInt(result: var string; x: int64) {...}{.raises: [], tags: [].}

  Converts integer to its string representation and appends it to `result`.

      var
        a = "123"
        b = 45
      a.addInt(b) # a <- "12345"

  Source Edit

    proc add(result: var string; x: int64) {...}{.deprecated: "Deprecated since v0.20, use \'addInt\'",
                                       raises: [], tags: [].}

  Deprecated: Deprecated since v0.20, use 'addInt'
  Source Edit

    proc addFloat(result: var string; x: float) {...}{.raises: [], tags: [].}

  Converts float to its string representation and appends it to `result`.

      var
        a = "123"
        b = 45.67
      a.addFloat(b) # a <- "12345.67"

  Source Edit

    proc add(result: var string; x: float) {...}{.deprecated: "Deprecated since v0.20, use \'addFloat\'",
                                       raises: [], tags: [].}

  Deprecated: Deprecated since v0.20, use 'addFloat'
  Source Edit

    proc `$`(x: uint64): string {...}{.noSideEffect, raises: [], tags: [].}

  The stringify operator for an unsigned integer argument. Returns `x` converted to a decimal string. Source Edit

    proc getCurrentException(): ref Exception {...}{.compilerproc, inline, gcsafe, locks: 0,
                                            raises: [], tags: [].}

  Retrieves the current exception; if there is none, `nil` is returned. Source Edit

    proc getCurrentExceptionMsg(): string {...}{.inline, gcsafe, locks: 0, raises: [], tags: [].}

  Retrieves the error message that was attached to the current exception; if there is none, `""` is returned. Source Edit

    proc onRaise(action: proc (e: ref Exception): bool {...}{.closure.}) {...}{.deprecated, raises: [],
        tags: [].}

  Deprecated

  Deprecated since version 0.18.1: No good usages of this feature are known.

  Can be used in a `try` statement to setup a Lisp-like condition system: This prevents the 'raise' statement to raise an exception but instead calls `action`. If `action` returns false, the exception has been handled and does not propagate further through the call stack.

  Source Edit

    proc setCurrentException(exc: ref Exception) {...}{.inline, gcsafe, locks: 0, raises: [],
        tags: [].}

  Sets the current exception.

  Warning: Only use this if you know what you are doing.

  Source Edit

    proc rawProc[T: proc](x: T): pointer {...}{.noSideEffect, inline.}

  Retrieves the raw proc pointer of the closure `x`. This is useful for interfacing closures with C. Source Edit

    proc rawEnv[T: proc](x: T): pointer {...}{.noSideEffect, inline.}

  Retrieves the raw environment pointer of the closure `x`. This is useful for interfacing closures with C. Source Edit

    proc finished[T: proc](x: T): bool {...}{.noSideEffect, inline.}

  can be used to determine if a first class iterator has finished. Source Edit

    proc quit(errormsg: string; errorcode = QuitFailure) {...}{.noreturn, raises: [], tags: [].}

  A shorthand for `echo(errormsg); quit(errorcode)`. Source Edit

    proc `/`(x, y: int): float {...}{.inline, noSideEffect, raises: [], tags: [].}

  Division of integers that results in a float.

  See also:

  - div
  - mod

      echo 7 / 5 # => 1.4

  Source Edit

    proc `[]`[T, U](s: string; x: HSlice[T, U]): string {...}{.inline.}

  Slice operation for strings. Returns the inclusive range `[s[x.a], s[x.b]]`:

      var s = "abcdef"
      assert s[1..3] == "bcd"

  Source Edit

    proc `[]=`[T, U](s: var string; x: HSlice[T, U]; b: string)

  Slice assignment for strings.

  If `b.len` is not exactly the number of elements that are referred to by `x`, a splice is performed:

  Examples:

      var s = "abcdefgh"
      s[1 .. ^2] = "xyz"
      assert s == "axyzh"

  Source Edit

    proc `[]`[Idx, T, U, V](a: array[Idx, T]; x: HSlice[U, V]): seq[T]

  Slice operation for arrays. Returns the inclusive range `[a[x.a], a[x.b]]`:

      var a = [1, 2, 3, 4]
      assert a[0..2] == @[1, 2, 3]

  Source Edit

    proc `[]=`[Idx, T, U, V](a: var array[Idx, T]; x: HSlice[U, V]; b: openArray[T])

  Slice assignment for arrays.

      var a = [10, 20, 30, 40, 50]
      a[1..2] = @[99, 88]
      assert a == [10, 99, 88, 40, 50]

  Source Edit

    proc `[]`[T, U, V](s: openArray[T]; x: HSlice[U, V]): seq[T]

  Slice operation for sequences. Returns the inclusive range `[s[x.a], s[x.b]]`:

      var s = @[1, 2, 3, 4]
      assert s[0..2] == @[1, 2, 3]

  Source Edit

    proc `[]=`[T, U, V](s: var seq[T]; x: HSlice[U, V]; b: openArray[T])

  Slice assignment for sequences.

  If `b.len` is not exactly the number of elements that are referred to by `x`, a splice is performed.

  Examples:

      var s = @"abcdefgh"
      s[1 .. ^2] = @"xyz"
      assert s == @"axyzh"

  Source Edit

    proc `[]`[T](s: openArray[T]; i: BackwardsIndex): T {...}{.inline.}

  Source Edit

    proc `[]`[Idx, T](a: array[Idx, T]; i: BackwardsIndex): T {...}{.inline.}

  Source Edit

    proc `[]`(s: string; i: BackwardsIndex): char {...}{.inline, raises: [], tags: [].}

  Source Edit

    proc `[]`[T](s: var openArray[T]; i: BackwardsIndex): var T {...}{.inline.}

  Source Edit

    proc `[]`[Idx, T](a: var array[Idx, T]; i: BackwardsIndex): var T {...}{.inline.}

  Source Edit

    proc `[]=`[T](s: var openArray[T]; i: BackwardsIndex; x: T) {...}{.inline.}

  Source Edit

    proc `[]=`[Idx, T](a: var array[Idx, T]; i: BackwardsIndex; x: T) {...}{.inline.}

  Source Edit

    proc `[]=`(s: var string; i: BackwardsIndex; x: char) {...}{.inline, raises: [], tags: [].}

  Source Edit

    proc slurp(filename: string): string {...}{.magic: "Slurp".}

  This is an alias for staticRead. Source Edit

    proc staticRead(filename: string): string {...}{.magic: "Slurp".}

  Compile-time readFile proc for easy resource embedding:

      const myResource = staticRead"mydatafile.bin"

  slurp is an alias for `staticRead`.

  Source Edit

    proc gorge(command: string; input = ""; cache = ""): string {...}{.magic: "StaticExec",
        raises: [], tags: [].}

  This is an alias for staticExec. Source Edit

    proc staticExec(command: string; input = ""; cache = ""): string {...}{.magic: "StaticExec",
        raises: [], tags: [].}

  Executes an external process at compile-time and returns its text output (stdout + stderr).

  If `input` is not an empty string, it will be passed as a standard input to the executed program.

      const buildInfo = "Revision " & staticExec("git rev-parse HEAD") &
                        "\nCompiled on " & staticExec("uname -v")

  gorge is an alias for `staticExec`.

  Note that you can use this proc inside a pragma like passc or passl.

  If `cache` is not empty, the results of `staticExec` are cached within the `nimcache` directory. Use `--forceBuild` to get rid of this caching behaviour then. `command & input & cache` (the concatenated string) is used to determine whether the entry in the cache is still valid. You can use versioning information for `cache`:

      const stateMachine = staticExec("dfaoptimizer", "input", "0.8.0")

  Source Edit

    proc gorgeEx(command: string; input = ""; cache = ""): tuple[output: string, exitCode: int] {...}{.
        raises: [], tags: [].}

  Similar to gorge but also returns the precious exit code. Source Edit

    proc `+=`[T: SomeInteger](x: var T; y: T) {...}{.magic: "Inc", noSideEffect.}

  Increments an integer. Source Edit

    proc `+=`[T: enum | bool](x: var T; y: T) {...}{.magic: "Inc", noSideEffect,
                                       deprecated: "use `inc` instead".}

  Deprecated: use `inc` instead
  Deprecated since v0.20: use `inc` instead. Source Edit

    proc `-=`[T: SomeInteger](x: var T; y: T) {...}{.magic: "Dec", noSideEffect.}

  Decrements an integer. Source Edit

    proc `-=`[T: enum | bool](x: var T; y: T) {...}{.magic: "Dec", noSideEffect,
                                       deprecated: "0.20.0, use `dec` instead".}

  Deprecated: 0.20.0, use `dec` instead
  Deprecated since v0.20: use `dec` instead. Source Edit

    proc `*=`[T: SomeInteger](x: var T; y: T) {...}{.inline, noSideEffect.}

  Binary `*=` operator for integers. Source Edit

    proc `+=`[T: float | float32 | float64](x: var T; y: T) {...}{.inline, noSideEffect.}

  Increments in place a floating point number. Source Edit

    proc `-=`[T: float | float32 | float64](x: var T; y: T) {...}{.inline, noSideEffect.}

  Decrements in place a floating point number. Source Edit

    proc `*=`[T: float | float32 | float64](x: var T; y: T) {...}{.inline, noSideEffect.}

  Multiplies in place a floating point number. Source Edit

    proc `/=`(x: var float64; y: float64) {...}{.inline, noSideEffect, raises: [], tags: [].}

  Divides in place a floating point number. Source Edit

    proc `/=`[T: float | float32](x: var T; y: T) {...}{.inline, noSideEffect.}

  Divides in place a floating point number. Source Edit

    proc `&=`(x: var string; y: string) {...}{.magic: "AppendStrStr", noSideEffect.}

  Appends in place to a string.

      var a = "abc"
      a &= "de" # a <- "abcde"

  Source Edit

    proc shallow[T](s: var seq[T]) {...}{.noSideEffect, inline.}

  Marks a sequence `s` as shallow. Subsequent assignments will not perform deep copies of `s`.

  This is only useful for optimization purposes.

  Source Edit

    proc shallow(s: var string) {...}{.noSideEffect, inline, raises: [], tags: [].}

  Marks a string `s` as shallow. Subsequent assignments will not perform deep copies of `s`.

  This is only useful for optimization purposes.

  Source Edit

    proc insert(x: var string; item: string; i = 0.Natural) {...}{.noSideEffect, raises: [], tags: [].}

  Inserts `item` into `x` at position `i`.

      var a = "abc"
      a.insert("zz", 0) # a <- "zzabc"

  Source Edit

    proc addEscapedChar(s: var string; c: char) {...}{.noSideEffect, inline, raises: [], tags: [].}

  Adds a char to string `s` and applies the following escaping:
  - replaces any `\` by `\\`
  - replaces any `'` by `\'`
  - replaces any `"` by `\"`
  - replaces any `\a` by `\\a`
  - replaces any `\b` by `\\b`
  - replaces any `\t` by `\\t`
  - replaces any `\n` by `\\n`
  - replaces any `\v` by `\\v`
  - replaces any `\f` by `\\f`
  - replaces any `\c` by `\\c`
  - replaces any `\e` by `\\e`
  - replaces any other character not in the set `{'\21..'\126'} by ``\xHH` where `HH` is its hexadecimal value.

  The procedure has been designed so that its output is usable for many different common syntaxes.

  Note: This is not correct for producing Ansi C code!

  Source Edit

    proc addQuoted[T](s: var string; x: T)

  Appends `x` to string `s` in place, applying quoting and escaping if `x` is a string or char.

  See addEscapedChar for the escaping scheme. When `x` is a string, characters in the range `{\128..\255}` are never escaped so that multibyte UTF-8 characters are untouched (note that this behavior is different from `addEscapedChar`).

  The Nim standard library uses this function on the elements of collections when producing a string representation of a collection. It is recommended to use this function as well for user-side collections. Users may overload `addQuoted` for custom (string-like) types if they want to implement a customized element representation.

      var tmp = ""
      tmp.addQuoted(1)
      tmp.add(", ")
      tmp.addQuoted("string")
      tmp.add(", ")
      tmp.addQuoted('c')
      assert(tmp == """1, "string", 'c'""")

  Source Edit

    proc safeAdd[T](x: var seq[T]; y: T) {...}{.noSideEffect, deprecated.}

  Deprecated
  Adds `y` to `x` unless `x` is not yet initialized; in that case, `x` becomes `@[y]`. Source Edit

    proc safeAdd(x: var string; y: char) {...}{.noSideEffect, deprecated, raises: [], tags: [].}

  Deprecated
  Adds `y` to `x`. If `x` is `nil` it is initialized to `""`. Source Edit

    proc safeAdd(x: var string; y: string) {...}{.noSideEffect, deprecated, raises: [], tags: [].}

  Deprecated
  Adds `y` to `x` unless `x` is not yet initialized; in that case, `x` becomes `y`. Source Edit

    proc locals(): RootObj {...}{.magic: "Plugin", noSideEffect, raises: [], tags: [].}

  Generates a tuple constructor expression listing all the local variables in the current scope.

  This is quite fast as it does not rely on any debug or runtime information. Note that in contrast to what the official signature says, the return type is not `RootObj` but a tuple of a structure that depends on the current scope. Example:

      proc testLocals() =
        var
          a = "something"
          b = 4
          c = locals()
          d = "super!"

        b = 1
        for name, value in fieldPairs(c):
          echo "name ", name, " with value ", value
        echo "B is ", b
      # -> name a with value something
      # -> name b with value 4
      # -> B is 1

  Source Edit

    proc deepCopy[T](x: var T; y: T) {...}{.noSideEffect, magic: "DeepCopy".}

  Performs a deep copy of `y` and copies it into `x`.

  This is also used by the code generator for the implementation of `spawn`.

  Source Edit

    proc deepCopy[T](y: T): T

  Convenience wrapper around `deepCopy` overload. Source Edit

    proc procCall(x: untyped) {...}{.magic: "ProcCall", compileTime, raises: [], tags: [].}

  Special magic to prohibit dynamic binding for method calls. This is similar to super in ordinary OO languages.

      # 'someMethod' will be resolved fully statically:
      procCall someMethod(a, b)

  Source Edit

    proc xlen(x: string): int {...}{.magic: "XLenStr", noSideEffect,
                            deprecated: "use len() instead", raises: [], tags: [].}

  Deprecated: use len() instead
  Deprecated since version 0.18.1. Use `len()` instead. Source Edit

    proc xlen[T](x: seq[T]): int {...}{.magic: "XLenSeq", noSideEffect,
                               deprecated: "use len() instead".}

  Deprecated: use len() instead

  Deprecated since version 0.18.1. Use `len()` instead.

  Returns the length of a sequence or a string without testing for 'nil'. This is an optimization that rarely makes sense.

  Source Edit

    proc `==`(x, y: cstring): bool {...}{.magic: "EqCString", noSideEffect, inline, raises: [],
                                tags: [].}

  Checks for equality between two `cstring` variables. Source Edit

    proc `==`(x: string; y: type(nil) | type(nil)): bool {...}{.error: "\'nil\' is now invalid for \'string\'; compile with --nilseqs:on for a migration period".}

  Source Edit

    proc `==`(x: type(nil) | type(nil); y: string): bool {...}{.error: "\'nil\' is now invalid for \'string\'; compile with --nilseqs:on for a migration period".}

  Source Edit

    proc substr(s: string; first, last: int): string {...}{.raises: [], tags: [].}

  Copies a slice of `s` into a new string and returns this new string.

  The bounds `first` and `last` denote the indices of the first and last characters that shall be copied. If `last` is omitted, it is treated as `high(s)`. If `last >= s.len`, `s.len` is used instead: This means `substr` can also be used to cut or limit a string's length.

  Examples:

      let a = "abcdefgh"
      assert a.substr(2, 5) == "cdef"
      assert a.substr(2) == "cdefgh"
      assert a.substr(5, 99) == "fgh"

  Source Edit

    proc substr(s: string; first = 0): string {...}{.raises: [], tags: [].}

  Source Edit

    proc toOpenArray[T](x: ptr UncheckedArray[T]; first, last: int): openArray[T] {...}{.
        magic: "Slice".}

  Source Edit

    proc toOpenArray(x: cstring; first, last: int): openArray[char] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArrayByte(x: cstring; first, last: int): openArray[byte] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArray[T](x: seq[T]; first, last: int): openArray[T] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArray[T](x: openArray[T]; first, last: int): openArray[T] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArray[I, T](x: array[I, T]; first, last: I): openArray[T] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArray(x: string; first, last: int): openArray[char] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArrayByte(x: string; first, last: int): openArray[byte] {...}{.magic: "Slice".}

  Source Edit

    proc toOpenArrayByte(x: openArray[char]; first, last: int): openArray[byte] {...}{.
        magic: "Slice".}

  Source Edit

    proc toOpenArrayByte(x: seq[char]; first, last: int): openArray[byte] {...}{.magic: "Slice".}

  Source Edit

# Iterators

    iterator countdown[T](a, b: T; step: Positive = 1): T {...}{.inline.}

  Counts from ordinal value `a` down to `b` (inclusive) with the given step count.

  `T` may be any ordinal type, `step` may only be positive.

  Note: This fails to count to `low(int)` if T = int for efficiency reasons.

      for i in countdown(7, 3):
        echo i # => 7; 6; 5; 4; 3

      for i in countdown(9, 2, 3):
        echo i # => 9; 6; 3

  Source Edit

    iterator countup[T](a, b: T; step: Positive = 1): T {...}{.inline.}

  Counts from ordinal value `a` to `b` (inclusive) with the given step count.

  `T` may be any ordinal type, `step` may only be positive.

  Note: This fails to count to `high(int)` if T = int for efficiency reasons.

      for i in countup(3, 7):
        echo i # => 3; 4; 5; 6; 7

      for i in countup(2, 9, 3):
        echo i # => 2; 5; 8

  Source Edit

    iterator `..`[T](a, b: T): T {...}{.inline.}

  An alias for `countup(a, b, 1)`.

  See also:

  - ..<

      for i in 3 .. 7:
        echo i # => 3; 4; 5; 6; 7

  Source Edit

    iterator `..`(a, b: int64): int64 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..` for convenience so that mixing integer types works better.

  See also:

  - ..<
  Source Edit

    iterator `..`(a, b: int32): int32 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..` for convenience so that mixing integer types works better.

  See also:

  - ..<
  Source Edit

    iterator `..`(a, b: uint64): uint64 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..` for convenience so that mixing integer types works better.

  See also:

  - ..<
  Source Edit

    iterator `..`(a, b: uint32): uint32 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..` for convenience so that mixing integer types works better.

  See also:

  - ..<
  Source Edit

    iterator `..<`[T](a, b: T): T {...}{.inline.}

  Source Edit

    iterator `..<`(a, b: int64): int64 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..<` for convenience so that mixing integer types works better. Source Edit

    iterator `..<`(a, b: int32): int32 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..<` for convenience so that mixing integer types works better. Source Edit

    iterator `..<`(a, b: uint64): uint64 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..<` for convenience so that mixing integer types works better. Source Edit

    iterator `..<`(a, b: uint32): uint32 {...}{.inline, raises: [], tags: [].}

  A type specialized version of `..<` for convenience so that mixing integer types works better. Source Edit

    iterator `||`[S, T](a: S; b: T; annotation: static string = "parallel for"): T {...}{.inline,
        magic: "OmpParFor", sideEffect.}

  OpenMP parallel loop iterator. Same as `..` but the loop may run in parallel.

  `annotation` is an additional annotation for the code generator to use. The default annotation is `parallel for`. Please refer to the OpenMP Syntax Reference for further information.

  Note that the compiler maps that to the `#pragma omp parallel for` construct of OpenMP and as such isn't aware of the parallelism in your code! Be careful! Later versions of `||` will get proper support by Nim's code generator and GC.

  Source Edit

    iterator `||`[S, T](a: S; b: T; step: Positive;
                      annotation: static string = "parallel for"): T {...}{.inline,
        magic: "OmpParFor", sideEffect.}

  OpenMP parallel loop iterator with stepping. Same as `countup` but the loop may run in parallel.

  `annotation` is an additional annotation for the code generator to use. The default annotation is `parallel for`. Please refer to the OpenMP Syntax Reference for further information.

  Note that the compiler maps that to the `#pragma omp parallel for` construct of OpenMP and as such isn't aware of the parallelism in your code! Be careful! Later versions of `||` will get proper support by Nim's code generator and GC.

  Source Edit

# Templates

    template `!=`(x, y: untyped): untyped

  Unequals operator. This is a shorthand for `not (x == y)`. Source Edit

    template `>=`(x, y: untyped): untyped

  "is greater or equals" operator. This is the same as `y <= x`. Source Edit

    template `>`(x, y: untyped): untyped

  "is greater" operator. This is the same as `y < x`. Source Edit

    template offsetOf[T; ](t: typedesc[T]; member: untyped): int

  Source Edit

    template offsetOf[T](value: T; member: untyped): int

  Source Edit

    template incl[T](x: var set[T]; y: set[T])

  Includes the set `y` in the set `x`.

      var a = {1, 3, 5, 7}
      var b = {4, 5, 6}
      a.incl(b)  # a <- {1, 3, 4, 5, 6, 7}

  Source Edit

    template excl[T](x: var set[T]; y: set[T])

  Excludes the set `y` from the set `x`.

      var a = {1, 3, 5, 7}
      var b = {3, 4, 5}
      a.excl(b)  # a <- {1, 7}

  Source Edit

    template `>=%`(x, y: untyped): untyped

  Treats `x` and `y` as unsigned and compares them. Returns true if `unsigned(x) >= unsigned(y)`. Source Edit

    template `>%`(x, y: untyped): untyped

  Treats `x` and `y` as unsigned and compares them. Returns true if `unsigned(x) > unsigned(y)`. Source Edit

    template `in`(x, y: untyped): untyped {...}{.dirty.}

  Sugar for `contains`.

      assert(1 in (1..3) == true)
      assert(5 in (1..3) == false)

  Source Edit

    template `notin`(x, y: untyped): untyped {...}{.dirty.}

  Sugar for `not contains`.

      assert(1 notin (1..3) == false)
      assert(5 notin (1..3) == true)

  Source Edit

    template `isnot`(x, y: untyped): untyped

  Negated version of is. Equivalent to `not(x is y)`.

      assert 42 isnot float
      assert @[1, 2] isnot enum

  Source Edit

    template unown(x: typed): untyped

  Source Edit

    template `<//>`(t: untyped): untyped

  Source Edit

    template disarm(x: typed)

  Useful for `disarming` dangling pointers explicitly for the

  --newruntime. Regardless of whether --newruntime is used or not |

  this sets the pointer or callback `x` to `nil`. This is an experimental API!

  Source Edit

    template accumulateResult(iter: untyped) {...}{.deprecated: "use `sequtils.toSeq` instead (more hygienic, sometimes more efficient)".}

  Deprecated: use `sequtils.toSeq` instead (more hygienic, sometimes more efficient)

  Deprecated since v0.19.2: use sequtils.toSeq instead.

  Helps to convert an iterator to a proc. sequtils.toSeq is more hygienic and efficient.

  Source Edit

    template newException(exceptn: typedesc; message: string;
                         parentException: ref Exception = nil): untyped

  Creates an exception object of type `exceptn` and sets its `msg` field to `message`. Returns the new exception object. Source Edit

    template likely(val: bool): bool

  Hints the optimizer that `val` is likely going to be true.

  You can use this template to decorate a branch condition. On certain platforms this can help the processor predict better which branch is going to be run. Example:

      for value in inputValues:
        if likely(value <= 100):
          process(value)
        else:
          echo "Value too big!"

  On backends without branch prediction (JS and the nimscript VM), this template will not affect code execution.

  Source Edit

    template unlikely(val: bool): bool

  Hints the optimizer that `val` is likely going to be false.

  You can use this proc to decorate a branch condition. On certain platforms this can help the processor predict better which branch is going to be run. Example:

      for value in inputValues:
        if unlikely(value > 100):
          echo "Value too big!"
        else:
          process(value)

  On backends without branch prediction (JS and the nimscript VM), this template will not affect code execution.

  Source Edit

    template formatErrorIndexBound[T](i, a, b: T): string

  Source Edit

    template formatErrorIndexBound[T](i, n: T): string

  Source Edit

    template `^`(x: int): BackwardsIndex

  Builtin roof operator that can be used for convenient array access. `a[^x]` is a shortcut for `a[a.len-x]`.

      let
        a = [1, 3, 5, 7, 9]
        b = "abcdefgh"

      echo a[^1] # => 9
      echo b[^2] # => g

  Source Edit

    template `..^`(a, b: untyped): untyped

  A shortcut for `.. ^` to avoid the common gotcha that a space between '..' and '^' is required. Source Edit

    template `..<`(a, b: untyped): untyped

  A shortcut for `a .. pred(b)`.

      for i in 5 ..< 9:
        echo i # => 5; 6; 7; 8

  Source Edit

    template `[]`(s: string; i: int): char

  Source Edit

    template `[]=`(s: string; i: int; val: char)

  Source Edit

    template `&=`(x, y: typed)

  Generic 'sink' operator for Nim.

  For files an alias for `write`. If not specialized further, an alias for `add`.

  Source Edit

    template currentSourcePath(): string

  returns the full file-system path of the current source Source Edit

    template rangeCheck(cond)

  Helper for performing user-defined range checks. Such checks will be performed only when the `rangechecks` compile-time option is enabled. Source Edit

    template closureScope(body: untyped): untyped

  Useful when creating a closure in a loop to capture local loop variables by their current iteration values. Example:

      var myClosure : proc()
      # without closureScope:
      for i in 0 .. 5:
        let j = i
        if j == 3:
          myClosure = proc() = echo j
      myClosure() # outputs 5. `j` is changed after closure creation
      # with closureScope:
      for i in 0 .. 5:
        closureScope: # Everything in this scope is locked after closure creation
          let j = i
          if j == 3:
            myClosure = proc() = echo j
      myClosure() # outputs 3

  Source Edit

    template once(body: untyped): untyped

  Executes a block of code only once (the first time the block is reached).

      proc draw(t: Triangle) =
        once:
          graphicsInit()
        line(t.p1, t.p2)
        line(t.p2, t.p3)
        line(t.p3, t.p1)

  Source Edit

# Exports

onFailedAssert, assert, doAssert, raiseAssert, failedAssertImpl, doAssertRaises, assertions, mitems, pairs, mpairs, mitems, mitems, items, mpairs, pairs, mpairs, mpairs, pairs, mitems, pairs, mitems, items, fields, iterators, items, items, items, items, pairs, fieldPairs, mpairs, fields, items, fieldPairs, items, $, $, $, $, $, dollars, $, $, $, $, $, $, $, $, $, $, len, widestrs, $, Utf16Char, newWideCString, WideCStringObj, $, newWideCString, newWideCString, WideCString, stderr, File, writeChars, readBytes, write, FileMode, write, stdout, writeFile, write, write, stdmsg, open, readFile, getFileHandle, writeLine, writeBuffer, readLine, reopen, write, readChar, getFileSize, endOfFile, write, getOsFileHandle, fmRead, writeBytes, readLines, io, write, getFilePos, stdin, setStdIoUnbuffered, fmReadWrite, readChars, open, fmAppend, fmReadWriteExisting, readBuffer, lines, readLine, write, close, flushFile, readAll, FileHandle, fmWrite, open, lines, write, setFilePos