syntax: improve highlighting, thanks to @ififi, closes #19

syntax/go.vim

@@ -32,19 +32,39 @@ endif
 if !exists("go_highlight_array_whitespace_error")
   let go_highlight_array_whitespace_error = 1
 endif
+
 if !exists("go_highlight_chan_whitespace_error")
   let go_highlight_chan_whitespace_error = 1
 endif
+
 if !exists("go_highlight_extra_types")
   let go_highlight_extra_types = 1
 endif
+
 if !exists("go_highlight_space_tab_error")
   let go_highlight_space_tab_error = 1
 endif
+
 if !exists("go_highlight_trailing_whitespace_error")
   let go_highlight_trailing_whitespace_error = 1
 endif
 
+if !exists("go_highlight_operators")
+	let go_highlight_operators = 1
+endif
+
+if !exists("go_highlight_functions")
+	let go_highlight_functions = 1
+endif
+
+if !exists("go_highlight_methods")
+	let go_highlight_methods = 1
+endif
+
+if !exists("go_highlight_structs")
+	let go_highlight_structs = 1
+endif
+
 syn case match
 
 syn keyword     goDirective         package import
@@ -83,8 +103,6 @@ hi def link     goComplexes         Type
 " elsewhere. Order matters here.
 syn match       goDeclaration       /\<func\>/
 
-syn match   	goFunction 	    "\%(\%(func\s\)\s*\)\@<=\h\%(\w\|\.\)*" 
-hi def link     goFunction          Function
 
 " Predefined functions and values
 syn keyword     goBuiltins          append cap close complex copy delete imag len
@@ -199,6 +217,52 @@ endif
 hi def link     goExtraType         Type
 hi def link     goSpaceError        Error
 
+
+
+" included from: https://github.com/athom/more-colorful.vim/blob/master/after/syntax/go.vim
+"
+" Comments; their contents
+syn keyword     goTodo              contained NOTE
+hi def link     goTodo              Todo
+
+
+" Operators; 
+if go_highlight_operators != 0
+	syn match goOperator /:=/
+	syn match goOperator />=/
+	syn match goOperator /<=/
+	syn match goOperator /==/
+	syn match goOperator /\s>\s/
+	syn match goOperator /\s<\s/
+	syn match goOperator /\s+\s/
+	syn match goOperator /\s-\s/
+	syn match goOperator /\s\*\s/
+	syn match goOperator /\s\/\s/
+	syn match goOperator /\s%\s/
+endif
+hi def link     goOperator					Operator
+
+" Functions; 
+if go_highlight_functions != 0
+	syn match goFunction							/\(func\s\+\)\@<=\w\+\((\)\@=/
+	syn match goFunction							/\()\s\+\)\@<=\w\+\((\)\@=/
+endif
+hi def link     goFunction					Function
+
+" Methods; 
+if go_highlight_methods != 0
+	syn match goMethod								/\(\.\)\@<=\w\+\((\)\@=/
+endif
+hi def link     goMethod						Type
+
+" Structs; 
+if go_highlight_structs != 0
+	syn match goStruct								/\(.\)\@<=\w\+\({\)\@=/
+	syn match goStructDef							/\(type\s\+\)\@<=\w\+\(\s\+struct\s\+{\)\@=/
+endif
+hi def link     goStruct						Function
+hi def link     goStructDef         Function
+
 " Search backwards for a global declaration to start processing the syntax.
 "syn sync match goSync grouphere NONE /^\(const\|var\|type\|func\)\>/