Add erlang support

1 files changed, 219 insertions, 0 deletions

diff --git a/autoload/erlang_complete.vim b/autoload/erlang_complete.vim
new file mode 100644
index 00000000..9d108fbc
--- /dev/null
+++ b/autoload/erlang_complete.vim
@@ -0,0 +1,219 @@
+" Vim omni completion file
+" Language:     Erlang
+" Author:       Oscar Hellström <oscar@oscarh.net>
+" Contributors: kTT (http://github.com/kTT)
+"               Ricardo Catalinas Jiménez <jimenezrick@gmail.com>
+"               Eduardo Lopez (http://github.com/tapichu)
+"               Zhihui Jiao (http://github.com/onlychoice)
+" License:      Vim license
+" Version:      2012/11/26
+
+if !exists('g:erlang_completion_cache')
+	let g:erlang_completion_cache = 1
+endif
+
+" Completion program path
+let s:erlang_complete_file = expand('<sfile>:p:h') . '/erlang_complete.erl'
+
+" Modules cache used to speed up the completion
+let s:modules_cache = {}
+
+" File cache for persistence between Vim sessions
+if filewritable(expand('<sfile>:p:h')) == 2
+	let s:file_cache = expand('<sfile>:p:h') . '/vimerl_cache'
+else
+	let s:file_cache = '/tmp/vimerl_cache'
+endif
+
+" Patterns for completions
+let s:erlang_local_func_beg    = '\(\<[0-9A-Za-z_-]*\|\s*\)$'
+let s:erlang_external_func_beg = '\<[0-9A-Za-z_-]\+:[0-9A-Za-z_-]*$'
+let s:erlang_blank_line        = '^\s*\(%.*\)\?$'
+
+" Main function for completion
+function erlang_complete#Complete(findstart, base)
+	let lnum = line('.')
+	let column = col('.')
+	let line = strpart(getline('.'), 0, column - 1)
+
+	" 1) Check if the char to the left of us are part of a function call
+	"
+	" Nothing interesting is written at the char just before the cursor
+	" This means _anything_ could be started here
+	" In this case, keyword completion should probably be used,
+	" for now we'll only try and complete local functions.
+	"
+	" TODO: Examine if we can stare Identifiers end complete on them
+	" Is this worth it? Is /completion/ of a "blank" wanted? Can we consider
+	" `(' interesting and check if we are in a function call etc.?
+	if line[column - 2] !~ '[0-9A-Za-z:_-]'
+		if a:findstart
+			return column
+		else
+			return s:ErlangFindLocalFunc(a:base)
+		endif
+	endif
+	
+	" 2) Function in external module
+	if line =~ s:erlang_external_func_beg
+		let delimiter = match(line, ':[0-9A-Za-z_-]*$') + 1
+		if a:findstart
+			return delimiter
+		else
+			let module = matchstr(line[:-2], '\<\k*\>$')
+			return s:ErlangFindExternalFunc(module, a:base)
+		endif
+	endif
+
+	" 3) Local function
+	if line =~ s:erlang_local_func_beg
+		let funcstart = match(line, ':\@<![0-9A-Za-z_-]*$')
+		if a:findstart
+			return funcstart
+		else
+			return s:ErlangFindLocalFunc(a:base)
+		endif
+	endif
+
+	" 4) Unhandled situation
+	if a:findstart
+		return -1
+	else
+		return []
+	endif
+endfunction
+
+" Find the next non-blank line
+function s:ErlangFindNextNonBlank(lnum)
+	let lnum = nextnonblank(a:lnum + 1)
+	let line = getline(lnum)
+
+	while line =~ s:erlang_blank_line && 0 != lnum
+		let lnum = nextnonblank(lnum + 1)
+		let line = getline(lnum)
+	endwhile
+
+	return lnum
+endfunction
+
+" Find external function names
+function s:ErlangFindExternalFunc(module, base)
+	" If the module is cached, load its functions
+	if has_key(s:modules_cache, a:module)
+		for field_cache in get(s:modules_cache, a:module)
+			if match(field_cache.word, a:base) == 0
+				call complete_add(field_cache)
+			endif
+		endfor
+
+		return []
+	endif
+
+	let functions = system(s:erlang_complete_file . ' ' . a:module)
+	for function_spec in split(functions, '\n')
+		if match(function_spec, a:base) == 0
+			let function_name = matchstr(function_spec, a:base . '\w*')
+			let field = {'word': function_name . '(', 'abbr': function_spec,
+				  \  'kind': 'f', 'dup': 1}
+			call complete_add(field)
+
+			" Populate the cache only when iterating over all the
+			" module functions (i.e. no prefix for the completion)
+			if g:erlang_completion_cache && a:base == ''
+				if !has_key(s:modules_cache, a:module)
+					let s:modules_cache[a:module] = [field]
+				else
+					let fields_cache = get(s:modules_cache, a:module)
+					let s:modules_cache[a:module] = add(fields_cache, field)
+				endif
+			endif
+
+			" The user entered some text, so stop the completion
+			if complete_check()
+				" The module couldn't be entirely cached
+				if has_key(s:modules_cache, a:module)
+					call remove(s:modules_cache, a:module)
+				endif
+				break
+			endif
+		endif
+	endfor
+
+	call s:ErlangWriteCache(a:module)
+
+	return []
+endfunction
+
+" Find local function names
+function s:ErlangFindLocalFunc(base)
+	" Begin at line 1
+	let lnum = s:ErlangFindNextNonBlank(1)
+
+	if "" == a:base
+		let base = '\w' " Used to match against word symbol
+	else
+		let base = a:base
+	endif
+
+	while 0 != lnum && !complete_check()
+		let line = getline(lnum)
+		let function_name = matchstr(line, '^' . base . '[0-9A-Za-z_-]\+(\@=')
+		if function_name != ""
+			call complete_add({'word': function_name, 'kind': 'f'})
+		endif
+		let lnum = s:ErlangFindNextNonBlank(lnum)
+	endwhile
+
+	return []
+endfunction
+
+function s:ErlangLoadCache()
+	if filereadable(s:file_cache)
+		for line in readfile(s:file_cache)
+			let cache_entry = eval(line)
+			" cache_entry is a dict with just one key with the
+			" module name and the function list we are going to
+			" add to the memory cache as the value of this key
+			for mod_name in keys(cache_entry)
+				let func_list = get(cache_entry, mod_name)
+				let s:modules_cache[mod_name] = func_list
+			endfor
+		endfor
+	endif
+endfunction
+
+function s:ErlangWriteCache(module)
+	" Write all the module functions to the cache file
+	if has_key(s:modules_cache, a:module)
+		let func_list = get(s:modules_cache, a:module)
+		if len(func_list) > 0
+			let cache_entry = {a:module : func_list}
+			execute 'redir >>' . s:file_cache
+			silent echon cache_entry
+			silent echon "\n"
+			redir END
+		endif
+	endif
+endfunction
+
+function s:ErlangPurgeCache(...)
+	for mod_name in a:000
+		if has_key(s:modules_cache, mod_name)
+			call remove(s:modules_cache, mod_name)
+		endif
+	endfor
+
+	" Delete the old cache file
+	call delete(s:file_cache)
+
+	" Write a new one
+	for mod_name in keys(s:modules_cache)
+		call s:ErlangWriteCache(mod_name)
+	endfor
+endfunction
+
+" Load the file cache when this script is autoloaded
+call s:ErlangLoadCache()
+
+" Command for removing modules from the cache
+command -nargs=+ ErlangPurgeCache silent call s:ErlangPurgeCache(<f-args>)