Ruby proc shorthands

autoload/sj/ruby.vim

@@ -297,6 +297,24 @@ function! sj#ruby#JoinWhenThen()
   return 0
 endfunction
 
+function! sj#ruby#SplitProcShorthand()
+  let pattern = '(&:\k\+)'
+
+  if sj#SearchUnderCursor(pattern) <= 0
+    return 0
+  endif
+
+  if search('(&:\zs\k\+)', '', line('.')) <= 0
+    return 0
+  endif
+
+  let method_name = expand('<cword>')
+  let body = " do |i|\ni.".method_name."\nend"
+
+  call sj#ReplaceMotion('Va(', body)
+  return 1
+endfunction
+
 function! sj#ruby#SplitBlock()
   let pattern = '\v\{(\s*\|.{-}\|)?\s*(.{-})\s*\}'
 
@@ -360,6 +378,9 @@ function! sj#ruby#JoinBlock()
 
   let replacement = do_line.' '.body.' '.end_line
 
+  " shorthand to_proc if possible
+  let replacement = substitute(replacement, '\s*{ |\(\k\+\)| \1\.\(\k\+\) }$', '(\&:\2)', '')
+
   call sj#ReplaceLines(do_line_no, end_line_no, replacement)
 
   return 1

doc/splitjoin.txt

@@ -258,6 +258,14 @@ Blocks ~
       puts b.to_s
     end
 <
+Block &-shorthand ~
+>
+    [1, 2, 3].map(&:to_s)
+
+    [1, 2, 3].map do |i|
+      i.to_s
+    end
+<
 Heredocs ~
 >
     string = 'something'

ftplugin/ruby/splitjoin.vim

@@ -2,6 +2,7 @@ if !exists('b:splitjoin_split_callbacks')
   let b:splitjoin_split_callbacks = [
         \ 'sj#ruby#SplitArrayLiteral',
         \ 'sj#ruby#SplitIfClause',
+        \ 'sj#ruby#SplitProcShorthand',
         \ 'sj#ruby#SplitBlock',
         \ 'sj#ruby#SplitOptions',
         \ 'sj#ruby#SplitCachingConstruct',

spec/plugin/perl_spec.rb

@@ -8,6 +8,11 @@
     vim.set(:shiftwidth, 2)
   end
 
+  after :all do
+    # The perl filetype messes with iskeyword...
+    vim.command('set iskeyword-=:')
+  end
+
   specify "suffix if-clauses" do
     set_file_contents 'print "a = $a\n" if $debug;'
 

spec/plugin/ruby_spec.rb

@@ -611,6 +611,34 @@
       EOF
     end
 
+    it "optimizes particular cases to &-shorthands" do
+      set_file_contents <<-EOF
+        [1, 2, 3, 4].map(&:to_s)
+      EOF
+
+      vim.search 'to_s'
+      split
+
+      assert_file_contents <<-EOF
+        [1, 2, 3, 4].map do |i|
+          i.to_s
+        end
+      EOF
+
+      set_file_contents <<-EOF
+        [1, 2, 3, 4].map do |whatever|
+          whatever.to_s
+        end
+      EOF
+
+      vim.search 'whatever|'
+      join
+
+      assert_file_contents <<-EOF
+        [1, 2, 3, 4].map(&:to_s)
+      EOF
+    end
+
     it "handles trailing code" do
       set_file_contents <<-EOF
         Bar.new { |one| two }.map(&:name)