It is definitely a compiler bug, as that error message is not clear what is happening.
I will fix it on master. Thank you. *José Valim* www.plataformatec.com.br Skype: jv.ptec Founder and Director of R&D On Thu, Feb 23, 2017 at 5:11 AM, Paul Schoenfelder < [email protected]> wrote: > Isn't the pin operator unnecessary/invalid here? Two bindings in a match > with the same name asserts that the two values are the same. > > Paul > > On Wed, Feb 22, 2017 at 9:44 PM Allen Madsen <[email protected]> > wrote: > >> Your non-method example isn't the same as the method example. The >> equivalent would be: >> >> [n, %{^n => result}] = [10, %{ 0 => 0, 10 => 55 }] >> >> In both cases I get `unbound variable ^n` on elixir 1.4.1. >> >> The behavior is surprising since this works: >> >> [n, ^n] = [10, 10] >> >> >> Allen Madsen >> http://www.allenmadsen.com >> >> On Wed, Feb 22, 2017 at 8:57 PM, pragdave <[email protected]> wrote: >> >> iex(16)> defmodule A do def _fib(n, %{ ^n => result }), do: result end** >> (MatchError) no match of right hand side value: :error >> >> Notice this is a compilation error. >> >> Some background. This is part of a Fibonacci function that uses a cache >> (the second parameter). If I get a cache hit, I want to return the >> corresponding value. >> >> The concept works outside the context of a function parameter list: >> >> iex(16)> cache = %{ 0 => 0, 10 => 55 }%{0 => 0, 10 => 55} >> iex(17)> n = 10; %{ ^n => result } = cache; result55 >> >> Elixir 1.5.0-dev (3094471) >> >> If it's a bug, I'll submit it. >> >> Cheers >> >> Dave >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "elixir-lang-core" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit https://groups.google.com/d/ >> msgid/elixir-lang-core/6c948795-eafd-4a05-af81- >> 857cf470daa5%40googlegroups.com >> <https://groups.google.com/d/msgid/elixir-lang-core/6c948795-eafd-4a05-af81-857cf470daa5%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "elixir-lang-core" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit https://groups.google.com/d/ >> msgid/elixir-lang-core/CAK-y3Cs_N%3DG1TEhAk6LC5uAeeiy9o_ >> gYix8%3DgzSK1icLEPjnFQ%40mail.gmail.com >> <https://groups.google.com/d/msgid/elixir-lang-core/CAK-y3Cs_N%3DG1TEhAk6LC5uAeeiy9o_gYix8%3DgzSK1icLEPjnFQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/elixir-lang-core/CAK%3D%2B-Ttp5MuRotrkP8LhhVx9nHRMbXbSZ4% > 3DFRnTBxV08tu1UNg%40mail.gmail.com > <https://groups.google.com/d/msgid/elixir-lang-core/CAK%3D%2B-Ttp5MuRotrkP8LhhVx9nHRMbXbSZ4%3DFRnTBxV08tu1UNg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4K1Ytq6iegKTSmbpUHAHKvFq5uEN_0nS1daMU4744pd0g%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
