Support for highlighting

[rodrigues]

Given I am viewing an Elixir file,
And the cursor is at a certain position in the screen (line, column),
I want to get the all ranges where the symbol at position appears.

Example:

defmodule Foo do
  @foo "foo"

  def foo(foo_arg), do: :foo
  defp foo_fn(arg_foo), do: :foobar
  defp foom, do: Bar.foo()

  def bar do
    foo = 1
    foo + 2
  end

  def foobar do
    foo = "foo"
    "#{foo}#{Bar.foo()}"
  end
end

If the cursor is on Bar.foo(), it should only highlight the two Bar.foo() calls, not the other occurrences of foo in the code, i.e. only the reocurrences of the same symbol.

defmodule Mod do
  def a do
    {:ok, 1}
  end
  
  def b do
    a()
  end

  def c do
    Other.a()
  end
end

Being at either a(), the definition or the call in b(), both should be highlighted, but not the one in c().

Local variables with same name but in different scopes shouldn't be considered the same symbol.

Not sure this is a very feasible problem to solve, but it seems that this library would be the right place for it. 🙂

That would allow elixir-ls to provide the documentHighlight feature: https://microsoft.github.io/language-server-protocol/specification#textDocument_documentHighlight

JakeBecker/elixir-ls#20

[msaraiva]

@rodrigues I've started changing the Parser and MetadataBuilder in order to provide column information. This is necessary for precise highlighting and other features like refactoring. After a couple of months with no time for any open source project, I might have a couple of days this week to finish this and some other pending issues.