[erlang-questions] Strange matching behavior

[Lukas Larsson]

On Thu, Sep 5, 2019 at 10:06 AM block.rxckin.beats@REDACTED <
block.rxckin.beats@REDACTED> wrote:

> Hi Lukas
>
> Updating 10.4.4 works fine for me thanks.
>

10.4.4 is the run-time version, not the compiler version. Though I get why
you are confused as that is what is printed when you start an erlang shell.


> Can I see the bug ticket for this behavior ?
>

I'm not sure which compiler fix it was that fixed this problem, but you can
see what was fixed in each patch here:
http://blog.erlang.org/cd/docs/maint-22/lib/compiler-7.4.4/doc/html/notes.html.
My guess would be that it is OTP-15838 that fixed the problem that you had.


>
> Jxck
>
>
> 2019年9月5日(木) 16:59 Lukas Larsson <lukas@REDACTED>:
>
>> Hello,
>>
>> On Thu, Sep 5, 2019 at 9:39 AM block.rxckin.beats@REDACTED <
>> block.rxckin.beats@REDACTED> wrote:
>>
>>> I found strange behavior, see code below.
>>>
>>> why last match doesn't works ?
>>>
>>
>> It is a bug in the compiler in OTP-22 that has been fixed. If you upgrade
>> to the latest OTP-22 patched version it works as it should.
>>
>> Lukas
>>
>>
>>>
>>>
>>> ```main.erl
>>> #!/usr/bin/env escript
>>> -module(main).
>>>
>>> -mode(compile).
>>> -compile(export_all).
>>>
>>> xy() ->
>>>     #{ 160506610  => x, 3960650446 => y }.
>>>
>>> x() ->
>>>     #{ 160506610  => x }.
>>>
>>> y() ->
>>>     #{ 3960650446 => y }.
>>>
>>> xy2() ->
>>>     #{ 888888888  => x, 9999999999 => y }.
>>>
>>> main(_) ->
>>>     #{ 160506610  := x } = xy(), % ok
>>>     #{ 3960650446 := y } = xy(), % ok
>>>
>>>     #{ 160506610  := x } = x(), % ok
>>>     #{ 3960650446 := y } = y(), % ok
>>>
>>>
>>>     #{ 888888888  := x,
>>>        9999999999 := y
>>>      } = xy2(), % ok
>>>
>>>
>>>     #{ 160506610  := x,
>>>        3960650446 := y
>>>      } = xy(), % no match of right hand side value, WHY ??
>>>
>>>     ok.
>>> ```
>>>
>>> Erlang: Erlang/OTP 22 [erts-10.4] [source] [64-bit] [smp:8:8]
>>> [ds:8:8:10] [async-threads:1] [hipe]
>>> OS: Ubuntu 19.04 disco
>>> _______________________________________________
>>> erlang-questions mailing list
>>> erlang-questions@REDACTED
>>> http://erlang.org/mailman/listinfo/erlang-questions
>>>
>> _______________________________________________
> erlang-questions mailing list
> erlang-questions@REDACTED
> http://erlang.org/mailman/listinfo/erlang-questions
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20190905/0ef1d452/attachment.htm>