Elixir - What is syntax for function definitions?

1
votes

Using Elixir V1.1.1 on OS X I am having problems getting my head around the Elixir function definition syntax.

Given a function definition:

def foobar(arg1, arg2), do: <<something>> end

It seems that in some cases the comma after the parenthesis is required, other times it is not. Likewise the colon after the 'do' and likewise the closing 'end'. I am sure I am vastly over-complicating the situation, but this seems like a weird setup for a programming language.

Under what circumstances are these elements required/optional?

1
elixir

1 Answers

7
votes

You've combined two forms of method definition there - the shorter one-line syntax and the longer do/end syntax.

If you have a one-line method, you can write like the following:

def foobar(foo, bar), do: baz

Note the comma, and no end.

If you have a multi-line method, the syntax is slightly different:

def foobar(foo, bar) do
  foo
  bar
end

Note no comma and the placement of the end.

Both types are described here: http://elixir-lang.org/getting-started/modules.html#named-functions (note the long form for Math.zero?/1, and the shorter form under the 'Function capturing' heading)