indent symbols based on whitespace

indent/elixir.vim

@@ -18,6 +18,7 @@ set cpo&vim
 let s:no_colon_before = ':\@<!'
 let s:no_colon_after  = ':\@!'
 let s:symbols_end     = '\]\|}'
+let s:symbols_start   = '\[\|{'
 let s:arrow           = '^.*->$'
 let s:pipeline        = '^\s*|>.*$'
 let s:skip_syntax     = '\%(Comment\|String\)$'
@@ -54,12 +55,19 @@ function! GetElixirIndent()
     let current_line = getline(v:lnum)
     let last_line = getline(lnum)
 
-    let splited_line = split(last_line, '\zs')
+    let split_line = split(last_line, '\zs')
     let opened_symbol = 0
-    let opened_symbol += count(splited_line, '[') - count(splited_line, ']')
-    let opened_symbol += count(splited_line, '{') - count(splited_line, '}')
-
-    let ind += (opened_symbol * &sw)
+    let opened_symbol += count(split_line, '[') - count(split_line, ']')
+    let opened_symbol += count(split_line, '{') - count(split_line, '}')
+
+    " if start symbol is followed by a character, indent based on the
+    " whitespace after the symbol, otherwise use the default shiftwidth
+    if last_line =~ '\('.s:symbols_start.'\).'
+      let opened_prefix = matchlist(last_line, '\('.s:symbols_start.'\)\s*')[0]
+      let ind += (opened_symbol * strlen(opened_prefix))
+    else
+      let ind += (opened_symbol * &sw)
+    endif
 
     if last_line =~ '^\s*\('.s:symbols_end.'\)' || last_line =~ s:indent_keywords
       let ind += &sw

spec/indent/lists_spec.rb

@@ -81,10 +81,20 @@ def test do
     .should be_elixir_indentation
   end
 
+  specify "lists without whitespace" do
+    <<-EOF
+    def project do
+      [{:bar, path: "deps/umbrella/apps/bar"},
+       {:umbrella, path: "deps/umbrella"}]
+    end
+    EOF
+    .should be_elixir_indentation
+  end
+
   specify "lists with line break after square brackets" do
     <<-EOF
     def project do
-      deps: [
+      [
         { :bar, path: "deps/umbrella/apps/bar" },
         { :umbrella, path: "deps/umbrella" }
       ]