Questions like this should be asked on the Elixir Forum. The problem with the expression `[x: 1, y: 2 | [z: 3]]` is that it is parsed as `[x: 1, y: (2 | [z: 3])]`. As you may guess, the subexpression `2 | [z: 3]` does not make sense.
There's actually a working way to build the keyword list you want: [x: 1, y: 2] ++ [z: 3]. On Wed, Sep 13, 2017 at 3:56 PM, Allen Madsen <[email protected]> wrote: > Yesterday I wrote code like the following: > > [x: 1, y: 2 | [z: 3]] > > I was really surprised when it didn't compile: > > ** (CompileError) iex:1: undefined function |/2 > (stdlib) lists.erl:1354: :lists.mapfoldl/3 > (stdlib) lists.erl:1355: :lists.mapfoldl/3 > > The non-shorthand version works fine. > > [{:x, 1}, {:y, 2} | [z: 3]] > #=> [x: 1, y: 2, z: 3] > > -- > 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/6e89a635-6642-4f42-ace8- > 4a36119fa4e5%40googlegroups.com > <https://groups.google.com/d/msgid/elixir-lang-core/6e89a635-6642-4f42-ace8-4a36119fa4e5%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/CAAPY6ePPtOKu%3D1%2BrxN0yXQF1Qm%3D%2BL0Q1ZtHmmmfjoLMWtn5Waw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
