Re: [PATCH v3] userdiff: add Elixir to supported userdiff languages

[Johannes Sixt <j6t@kdbg.org>]

Please keep the Cc list when you send new patch versions. Also, it is
customary to send them as replies to the earlier iterations, so that
they all end up in the same thread.

Am 07.11.19 um 00:49 schrieb Łukasz Niemier:
> Adds support for xfuncref in Elixir[1] language which is Ruby-like
> language that runs on Erlang[3] Virtual Machine (BEAM).
> 
> [1]: https://elixir-lang.org
> [2]: https://www.erlang.org

Thanks! Much appreciated.

> 
> Signed-off-by: Łukasz Niemier <lukasz@niemier.pl>
> ---

> diff --git a/t/t4018/elixir-do-not-pick-end b/t/t4018/elixir-do-not-pick-end
> new file mode 100644
> index 0000000000..fae08ba7e8
> --- /dev/null
> +++ b/t/t4018/elixir-do-not-pick-end
> @@ -0,0 +1,5 @@
> +defmodule RIGHT do
> +end
> +#
> +#
> +# ChangeMe; do not pick up 'end' line

OK.

> diff --git a/t/t4018/elixir-ex-unit-test b/t/t4018/elixir-ex-unit-test
> new file mode 100644
> index 0000000000..0560a2b697
> --- /dev/null
> +++ b/t/t4018/elixir-ex-unit-test
> @@ -0,0 +1,6 @@
> +defmodule Test do
> +  test "RIGHT" do
> +    assert true == true
> +    assert ChangeMe
> +  end
> +end

A test, and also indented. Good.

> diff --git a/t/t4018/elixir-module-func b/t/t4018/elixir-module-func
> new file mode 100644
> index 0000000000..c9910d0675
> --- /dev/null
> +++ b/t/t4018/elixir-module-func
> @@ -0,0 +1,8 @@
> +defmodule Foo do
> +  def fun(RIGHT) do
> +     # Code
> +     # Code
> +     # Code
> +     ChangeMe
> +  end
> +end

An indented function. Good.

These other tests (which I stripped away) ensure that the hunk header
pattern does not become too restrictive. They all look good.

> diff --git a/userdiff.c b/userdiff.c
> index e187d356f6..577053c10a 100644
> --- a/userdiff.c
> +++ b/userdiff.c
> @@ -32,6 +32,18 @@ PATTERNS("dts",
>  	 /* Property names and math operators */
>  	 "[a-zA-Z0-9,._+?#-]+"
>  	 "|[-+*/%&^|!~]|>>|<<|&&|\\|\\|"),
> +PATTERNS("elixir",
> +	 "^[ \t]*((def(macro|module|impl|protocol|p)?|test)[ \t].*)$",
> +	 /* Atoms, names, and module attributes */
> +	 "|[@:]?[a-zA-Z0-9@_?!]+"

There are no single- and double-quote anymore. An oversight? Or an error
in the earlier iteration?

> +	 /* Numbers with specific base */
> +	 "|[-+]?0[xob][0-9a-fA-F]+"
> +	 /* Numbers */
> +	 "|[-+]?[0-9][0-9_.]*([eE][-+]?[0-9_]+)?"

The leading optional sign may be problematic. When a patch changes "i+1"
to "i+2", it would be highlighted as "i{-+1-}{++2+}" instead of as
"i+{-1-}{+2+}". You could remove the leading optional sign and let it be
processed as an operator. But we also have an optional sign in the cpp
pattern as well, and haven't noticed it until now, so...

> +	 /* Operators and atoms that represent them */
> +	 "|:?(\\+\\+|--|\\.\\.|~~~|<>|\\^\\^\\^|<?\\|>|<<<?|>?>>|<<?~|~>?>|<~>|<=|>=|===?|!==?|=~|&&&?|\\|\\|\\|?|=>|<-|\\\\\\\\|->)"
> +	 /* Not real operators, but should be grouped */
> +	 "|:?%[A-Za-z0-9_.]\\{\\}?"),
>  IPATTERN("fortran",
>  	 "!^([C*]|[ \t]*!)\n"
>  	 "!^[ \t]*MODULE[ \t]+PROCEDURE[ \t]\n"
> 

In summary, this version looks good!

Acked-by: Johannes Sixt <j6t@kdbg.org>

-- Hannes