The Ring programming language version 1.8 book - Part 82 of 202
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This document provides an overview of command line options available in the Ring programming language. Some key options include: - -tokens, which prints a list of tokens in the source code file. - -rules, which prints grammar rules applied to the tokens. - -ic and -icfinal, which print the intermediate and final bytecode before and after execution. - -cgi, which prints HTTP response headers before error messages. - -norun, which compiles but does not run the program. - -ins, which prints instruction operation codes before execution. - -performance, which prints clock times before and after program execution. - -go, which generates an object file.
![Ring Documentation, Release 1.8
test() { main([:one,:two,:three]) }
myclass func test() {
see "Testing User Types!" + nl
return new myclass
}
package mypackage {
public class myclass {
public static void func main(list args) {
see "welcome" + nl
see args
}
}
}
68.4 Using Types inside Code
Also you can use the types inside the code (not only the function prototype)
Example:
load "typehints.ring"
int sum = sum(3,4)
string msg = sayHello("Mahmoud")
see "Sum = " + sum + nl + msg + nl
int func sum(int x,int y) {
return x+y ;
}
string func sayHello(string name) {
return "Hello " + name ;
}
68.5 Rules
• To use the types in the function prototype you must use ‘(‘ and ‘)’ around parameters
• To use the types in the function code, You must set the variable value (Assignment).
The next types are defined by the library
# Low Level Types
char
unsigned
signed
int
short
long
float
68.4. Using Types inside Code 788](https://image.slidesharecdn.com/811ring-180828103536/85/The-Ring-programming-language-version-1-8-book-Part-82-of-202-8-320.jpg)
The Ring programming language version 1.8 book - Part 82 of 202
- 1. Ring Documentation, Release 1.8 Hello How are you? Welcome to Ring one two three 67.6 Using $ and @ in the start of the variable name You can use any unicode character in the variable name also we can use $ and @ in the name. This feature may help, for example we can start global variables with $ and the object attributes with @. In other languages like Ruby this is the rule, In the Ring language this is just an option without any force from the Compiler. example: $global_variable = 5 new test { hello() } class test @instance_variable = 10 func hello local_variable = 15 see "Global : " + $global_variable + nl + "Instance : " + @instance_variable + nl + "Local : " + local_variable + nl Output: Global : 5 Instance : 10 Local : 15 67.7 Using the ‘elseif’ keyword as ‘but’ in if statement if you don’t like the ‘but’ keyword in if statement Then you can use the ‘elseif’ keyword. Example: give x if x = 1 see "one" elseif x=2 see "two" elseif x=3 see "three" elseif x=4 see "four" else see "other" ok see nl 67.6. Using $ and @ in the start of the variable name 781
- 2. Ring Documentation, Release 1.8 67.8 Using the ‘else’ keyword as ‘other’ in switch statement if you don’t like the ‘other’ keyword in switch statement Then you can use the ‘else’ keyword. Also you can replace ‘else’ with ‘other’ in if statement. i.e. ‘other’ keyword is the same as ‘else’ keyword. Example: x = 1 switch x on 10 see "10" + nl else see "not 10" + nl end Output: not 10 67.9 Using the ‘end’ keyword in different control structures We can use the ‘end’ keyword to close different control structures • If statement • For loop • Switch • While • Try-Catch Example: see "if statement.." + nl x = 1 if x = 1 see "one" + nl elseif x=2 see "two" + nl elseif x=3 see "three" + nl end see "for loop.." + nl for t = 1 to 10 see t end see nl see "switch..." + nl x = 1 switch x on 1 see "one" + nl on 2 see "two" + nl end 67.8. Using the ‘else’ keyword as ‘other’ in switch statement 782
- 3. Ring Documentation, Release 1.8 see "try catch..." + nl try x = 1 / 0 catch see "catching error" + nl end Output: if statement.. one for loop.. 12345678910 switch... one try catch... catching error 67.10 Using braces to start and end different control structures We can use braces { } to start and end different control structures • If statement • For loop • Switch • While • Try-Catch Example: see "if statement.." + nl x = 1 if x = 1 { see "one" + nl elseif x=2 see "two" + nl elseif x=3 see "three" + nl } see "for loop.." + nl for t = 1 to 10 { see t } see nl see "switch..." + nl x = 1 switch x { on 1 see "one" + nl on 2 see "two" + nl } see "try catch..." + nl try { 67.10. Using braces to start and end different control structures 783
- 4. Ring Documentation, Release 1.8 x = 1 / 0 catch see "catching error" + nl } Output: if statement.. one for loop.. 12345678910 switch... one try catch... catching error 67.11 Using ‘put’ and ‘get’ as ‘see’ and ‘give’ We can replace the ‘see’ keyword with the ‘put’ keyword. Also we can replacew the ‘give’ keyword with the ‘get’ keyword. Example: put "Hello World" + nl put "Enter Your Name ? " Get Name Put "Hello " + Name 67.12 Using ‘case’ as ‘on’ in switch statements We can replace the ‘on’ keyword with ‘case’ keyword in the switch statement. Example (1) : for x=1 to 10 switch x case 1 put "one" + nl case 2 put "two" + nl case 3 put "thre" + nl else put "else" + nl end end Example (2) : for x=1 to 10 { switch x { case 1 put "one" + nl case 2 put "two" + nl case 3 put "thre" + nl else put "else" + nl } } 67.11. Using ‘put’ and ‘get’ as ‘see’ and ‘give’ 784
- 5. Ring Documentation, Release 1.8 67.13 Using ‘def’ as ‘func’ in functions/methods definition We can use the ‘def’ keyword as the ‘func’ keyword to define functions and methods. Example: one() two() def one put "one" + nl def two put "two" + nl 67.14 Using braces { } in Packages/Classes/Functions Example: load "stdlib.ring" import mypackage new myclass { myfunc() } package mypackage { class myclass { func myfunc { print("Hello, World!n") } } } 67.15 Using ‘end’ keyword after Packages/Classes/Functions Example: import mypackage new myclass { myfunc() } package mypackage class myclass def myfunc put "Hello, World!" end end end 67.13. Using ‘def’ as ‘func’ in functions/methods definition 785
- 6. Ring Documentation, Release 1.8 67.16 Using ‘endpackage’/’endclass’/’endfunc’ keywords after Pack- ages/Classes/Functions Example: import mypackage new myclass { myfunc() } package mypackage class myclass func myfunc see "welcome" + nl endfunc endclass endpackage 67.17 Ignore new lines after keywords Starting from Ring 1.8 the compiler will ignore new lines after keywords that expect tokens after it Example: see " Hello, World! " test() func #======================# Test #======================# ? " Hello from the Test function " Output: Hello, World! Hello from the Test function 67.16. Using ‘endpackage’/’endclass’/’endfunc’ keywords after Packages/Classes/Functions 786
- 7. CHAPTER SIXTYEIGHT INTRODUCTION TO THE TYPE HINTS LIBRARY In this chapter we will learn about the Type Hints Library 68.1 Why Type Hints? Using this library we can add the type information to the source code which will be very useful for tools like • Code Editors • Static-Analysis Note: Ring is a dynamic language, No type checking will be done by the compiler. 68.2 Example The next example will use the Type Hints library load "typehints.ring" see sum(3,4) + nl ; see sayHello("Mahmoud"); int func sum(int x,int y) { return x+y ; } string func sayHello(string name) { return "Hello " + name ; } 68.3 User Types The Type Hints library is very powerful and will support user types (Classes) automatically Example: load "typehints.ring" import mypackage 787
- 8. Ring Documentation, Release 1.8 test() { main([:one,:two,:three]) } myclass func test() { see "Testing User Types!" + nl return new myclass } package mypackage { public class myclass { public static void func main(list args) { see "welcome" + nl see args } } } 68.4 Using Types inside Code Also you can use the types inside the code (not only the function prototype) Example: load "typehints.ring" int sum = sum(3,4) string msg = sayHello("Mahmoud") see "Sum = " + sum + nl + msg + nl int func sum(int x,int y) { return x+y ; } string func sayHello(string name) { return "Hello " + name ; } 68.5 Rules • To use the types in the function prototype you must use ‘(‘ and ‘)’ around parameters • To use the types in the function code, You must set the variable value (Assignment). The next types are defined by the library # Low Level Types char unsigned signed int short long float 68.4. Using Types inside Code 788
- 9. Ring Documentation, Release 1.8 double void # High Level Types string list number object # Other public static abstract protected override 68.5. Rules 789
- 10. CHAPTER SIXTYNINE COMMAND LINE OPTIONS The ring language takes source code file (.ring) or the object file (.ringo) as input to execute, also the language provide other options like Option Description -tokens Print a list of tokens in the source code file -rules Print grammar rules applied on the tokens -ic Print the intermediate byte code (before execution) -icfinal Print the final byte code (after execution) -cgi Print http response header before error messages -norun Don’t run the program after compiling -ins Print instruction operation code before execution -performance Print clock before and after program execution -go Generate Object File -w Display Warnings 69.1 Printing Tokens Example: Func Main See "Hello World" + nl for x = 1 to 10 see x + nl next test() func test see "welcome" + nl o1 = new point { x=10 y=20 z=30 } see o1 class point x y z Command: ring test.ring -tokens -norun Output: =================================================== Tokens - Generated by the Scanner =================================================== 790