[#88240] [Ruby trunk Feature#14759] [PATCH] set M_ARENA_MAX for glibc malloc — sam.saffron@...
Issue #14759 has been updated by sam.saffron (Sam Saffron).
3 messages
2018/08/01
[#88251] Re: [ruby-alerts:8236] failure alert on trunk@P895 (NG (r64134)) — Eric Wong <normalperson@...>
[email protected] wrote:
3 messages
2018/08/01
[#88305] [Ruby trunk Bug#14968] [PATCH] io.c: make all pipes nonblocking by default — normalperson@...
Issue #14968 has been reported by normalperson (Eric Wong).
4 messages
2018/08/06
[#88331] [Ruby trunk Feature#13618] [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid — samuel@...
Issue #13618 has been updated by ioquatix (Samuel Williams).
3 messages
2018/08/08
[#88342] [Ruby trunk Feature#14955] [PATCH] gc.c: use MADV_FREE to release most of the heap page body — ko1@...
Issue #14955 has been updated by ko1 (Koichi Sasada).
3 messages
2018/08/08
[#88433] [Ruby trunk Feature#13618] [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid — ko1@...
SXNzdWUgIzEzNjE4IGhhcyBiZWVuIHVwZGF0ZWQgYnkga28xIChLb2ljaGkgU2FzYWRhKS4KCgpX
4 messages
2018/08/10
[#88467] Re: [Ruby trunk Feature#13618] [PATCH] auto fiber schedule for rb_wait_for_single_fd and rb_waitpid
— Eric Wong <normalperson@...>
2018/08/14
a28xQGF0ZG90Lm5ldCB3cm90ZToKPiBJc3N1ZSAjMTM2MTggaGFzIGJlZW4gdXBkYXRlZCBieSBr
[#88475] [Ruby trunk Misc#14937] [PATCH] thread_pthread: lazy-spawn timer-thread only on contention — ko1@...
Issue #14937 has been updated by ko1 (Koichi Sasada).
3 messages
2018/08/14
[#88491] Re: [ruby-cvs:71466] k0kubun:r64374 (trunk): test_function.rb: skip running test — Eric Wong <normalperson@...>
[email protected] wrote:
5 messages
2018/08/15
[#88495] Re: [ruby-cvs:71466] k0kubun:r64374 (trunk): test_function.rb: skip running test
— Takashi Kokubun <takashikkbn@...>
2018/08/15
SSBzZWUuIFBsZWFzZSByZW1vdmUgdGhlIHRlc3QgaWYgdGhlIHRlc3QgaXMgdW5uZWNlc3Nhcnku
[#88496] Re: [ruby-cvs:71466] k0kubun:r64374 (trunk): test_function.rb: skip running test
— Eric Wong <normalperson@...>
2018/08/15
Takashi Kokubun <[email protected]> wrote:
[#88523] [Ruby trunk Bug#14999] ConditionVariable doesn't reacquire the Mutex if Thread#kill-ed — eregontp@...
Issue #14999 has been updated by Eregon (Benoit Daloze).
4 messages
2018/08/17
[#88524] Re: [Ruby trunk Bug#14999] ConditionVariable doesn't reacquire the Mutex if Thread#kill-ed
— Eric Wong <normalperson@...>
2018/08/18
[email protected] wrote:
[#88549] [Ruby trunk Bug#14999] ConditionVariable doesn't reacquire the Mutex if Thread#kill-ed — eregontp@...
Issue #14999 has been updated by Eregon (Benoit Daloze).
3 messages
2018/08/19
[#88676] [Ruby trunk Misc#15014] thread.c: use rb_hrtime_scalar for high-resolution time operations — ko1@...
Issue #15014 has been updated by ko1 (Koichi Sasada).
5 messages
2018/08/27
[#88677] Re: [Ruby trunk Misc#15014] thread.c: use rb_hrtime_scalar for high-resolution time operations
— Eric Wong <normalperson@...>
2018/08/27
[email protected] wrote:
[#88678] Re: [Ruby trunk Misc#15014] thread.c: use rb_hrtime_scalar for high-resolution time operations
— Koichi Sasada <ko1@...>
2018/08/27
On 2018/08/27 16:16, Eric Wong wrote:
[#88716] Re: [ruby-dev:43715] [Ruby 1.9 - Bug #595] Fiber ignores ensure clause — Eric Wong <normalperson@...>
Koichi Sasada wrote:
4 messages
2018/08/29
[#88723] [Ruby trunk Bug#15041] [PATCH] cont.c: set th->root_fiber to current fiber at fork — ko1@...
Issue #15041 has been updated by ko1 (Koichi Sasada).
3 messages
2018/08/29
[#88767] [Ruby trunk Bug#15050] GC after forking with fibers crashes — ko1@...
Issue #15050 has been updated by ko1 (Koichi Sasada).
7 messages
2018/08/31
[#88769] Re: [Ruby trunk Bug#15050] GC after forking with fibers crashes
— Eric Wong <normalperson@...>
2018/08/31
Koichi Sasada <[email protected]> wrote:
[#88770] Re: [Ruby trunk Bug#15050] GC after forking with fibers crashes
— Koichi Sasada <ko1@...>
2018/08/31
[#88773] Re: [Ruby trunk Bug#15050] GC after forking with fibers crashes
— Eric Wong <normalperson@...>
2018/08/31
Koichi Sasada <[email protected]> wrote:
[#88774] Re: [ruby-alerts:8955] failure alert on trunk@P895 (NG (r64594)) — Eric Wong <normalperson@...>
[email protected] wrote:
3 messages
2018/08/31
[ruby-core:88463] [Ruby trunk Feature#14912] Introduce pattern matching syntax
From:
zverok.offline@...
Date:
2018-08-13 12:07:11 UTC
List:
ruby-core #88463
Issue #14912 has been updated by zverok (Victor Shepelev).
> Btw, won't it better to introduce a new expression named `match` than to extend `case`?
I have exactly the opposite question: do we really need `in`, why not reuse `when`?.. For all reasonable explanations, case+when IS Ruby's "pattern-matching" (however limited it seems), and I believe introducing new keywords with "similar yet more powerful" behavior will lead to a deep confusion.
----------------------------------------
Feature #14912: Introduce pattern matching syntax
https://bugs.ruby-lang.org/issues/14912#change-73529
* Author: ktsj (Kazuki Tsujimoto)
* Status: Open
* Priority: Normal
* Assignee:
* Target version:
----------------------------------------
I propose new pattern matching syntax.
# Pattern syntax
Here's a summary of pattern syntax.
```
# case version
case expr
in pat [if|unless cond]
...
in pat [if|unless cond]
...
else
...
end
pat: var # Variable pattern. It matches any value, and binds the variable name to that value.
| literal # Value pattern. The pattern matches an object such that pattern === object.
| Constant # Ditto.
| var_ # Ditto. It is equivalent to pin operator in Elixir.
| (pat, ..., *var, pat, ..., id:, id: pat, ..., **var) # Deconstructing pattern. See below for more details.
| pat(pat, ...) # Ditto. Syntactic sugar of (pat, pat, ...).
| pat, ... # Ditto. You can omit the parenthesis (top-level only).
| pat | pat | ... # Alternative pattern. The pattern matches if any of pats match.
| pat => var # As pattern. Bind the variable to the value if pat match.
# one-liner version
$(pat, ...) = expr # Deconstructing pattern.
```
The patterns are run in sequence until the first one that matches.
If no pattern matches and no else clause, NoMatchingPatternError exception is raised.
## Deconstructing pattern
This is similar to Extractor in Scala.
The patten matches if:
* An object have #deconstruct method
* Return value of #deconstruct method must be Array or Hash, and it matches sub patterns of this
```
class Array
alias deconstruct itself
end
case [1, 2, 3, d: 4, e: 5, f: 6]
in a, *b, c, d:, e: Integer | Float => i, **f
p a #=> 1
p b #=> [2]
p c #=> 3
p d #=> 4
p i #=> 5
p f #=> {f: 6}
e #=> NameError
end
```
This pattern can be used as one-liner version like destructuring assignment.
```
class Hash
alias deconstruct itself
end
$(x:, y: (_, z)) = {x: 0, y: [1, 2]}
p x #=> 0
p z #=> 2
```
# Sample code
```
class Struct
def deconstruct; [self] + values; end
end
A = Struct.new(:a, :b)
case A[0, 1]
in (A, 1, 1)
:not_match
in A(x, 1) # Syntactic sugar of above
p x #=> 0
end
```
```
require 'json'
$(x:, y: (_, z)) = JSON.parse('{"x": 0, "y": [1, 2]}', symbolize_names: true)
p x #=> 0
p z #=> 2
```
# Implementation
* https://github.com/k-tsj/ruby/tree/pm2.7-prototype
* Test code: https://github.com/k-tsj/ruby/blob/pm2.7-prototype/test_syntax.rb
# Design policy
* Keep compatibility
* Don't define new reserved words
* 0 conflict in parse.y. It passes test/test-all
* Be Ruby-ish
* Powerful Array, Hash support
* Encourage duck typing style
* etc
* Optimize syntax for major use case
* You can see several real use cases of pattern matching at following links :)
* https://github.com/k-tsj/power_assert/blob/8e9e0399a032936e3e3f3c1f06e0d038565f8044/lib/power_assert.rb#L106
* https://github.com/k-tsj/pattern-match/network/dependents
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