Redesign spellchecking

Highlightning of misspelled words is accomplished by changing their style
to win.STYLE_INFO before each draw (this changes also the color of vis:info messages).
To improve the performance only the visible viewport is checked without getting
corrections.

Misspelled words can be ignored till the editor exits.

1 files changed, 113 insertions, 67 deletions

diff --git a/spellcheck.lua b/spellcheck.lua
index 85d6ef9..4bb06e4 100644
--- a/spellcheck.lua
+++ b/spellcheck.lua
@@ -1,93 +1,122 @@
--- Copyright (c) 2017 Florian Fischer. All rights reserved.
+-- Copyright (c) 2017-2019 Florian Fischer. All rights reserved.
 -- Use of this source code is governed by a MIT license found in the LICENSE file.
 
-local module = {}
-module.lang = os.getenv("LANG"):sub(0,5) or "en_US"
--- TODO use more spellcheckers (aspell/hunspell)
+local spellcheck = {}
+spellcheck.lang = os.getenv("LANG"):sub(0,5) or "en_US"
 if os.execute("type enchant &>/dev/null") then
-	module.cmd = "enchant -d %s -a"
+	spellcheck.cmd = "enchant -d %s -a"
+	spellcheck.list_cmd = "enchant -l -d %s -a"
+elseif os.execute("type enchant-2 &>/dev/null") then
+	spellcheck.cmd = "enchant-2 -d %s -a"
+	spellcheck.list_cmd = "enchant-2 -l -d %s -a"
 elseif os.execute("type aspell &>/dev/null") then
-	module.cmd = "aspell -l %s -a"
+	spellcheck.cmd = "aspell -l %s -a"
+	spellcheck.list_cmd = "aspell list -l %s -a"
 elseif os.execute("type hunspell &>/dev/null") then
-	module.cmd = "hunspell -d %s"
+	spellcheck.cmd = "hunspell -d %s"
+	spellcheck.list_cmd = "hunspell -l -d %s"
 else
    return nil
 end
 
-function spellcheck(file, range)
-	local cmd = module.cmd:format(module.lang)
-	local ret, so, se = vis:pipe(file, range, cmd)
+spellcheck.enabled = {}
 
-	if ret ~= 0 then
-		return ret, se
+local ignored = {}
+
+local last_viewport, last_typos = nil, nil
+
+vis.events.subscribe(vis.events.WIN_HIGHLIGHT, function(win)
+	if not spellcheck.enabled[win] or not win:style_define(win.STYLE_INFO, "fore:red") then
+		return false
 	end
+	local viewport = win.viewport
+	local viewport_text = win.file:content(viewport)
 
-	local word_corrections = so:gmatch("(.-)\n")
-	-- skip header line
-	word_corrections()
-
-	local orig = file:content(range)
-	local new = orig:gsub("%S+", function(w)
-		local correction = word_corrections()
-		-- empty correction means a new line in range
-		if correction == "" then
-			correction = word_corrections()
-		end
-		if correction and correction ~= "*" then
-			-- get corrections
-			local orig, pos, sug = correction:match("& (%S+) %d+ (%d+): (.*)")
-			if not orig then
-				orig = correction:match("# (%S+).*")
-				vis:info("No correction availlable for " .. orig .. ".")
-			end
-			if orig ~= w then
-				orig = orig or "nil"
-				vis:message("Bad things happend!! Correction: " .. orig  .. " is not for " .. w)
-				return w
-			end
-			-- select a correction
-			local cmd = 'printf "' .. sug:gsub(", ", "\\n") .. '\\n" | vis-menu'
-			local f = io.popen(cmd)
-			correction = f:read("*all")
-			-- trim correction
-			correction = correction:match("%S+")
-			f:close()
-			if correction then
-				return correction
-			end
-		end
-	end)
+	local typos = ""
 
-	if orig ~= new then
-		file:delete(range)
-		file:insert(range.start, new)
+	if last_viewport == viewport_text then
+		typos = last_typos
+	else
+		local cmd = spellcheck.list_cmd:format(spellcheck.lang)
+		local ret, so, se = vis:pipe(win.file, viewport, cmd)
+		if ret ~= 0 then
+			vis:message("calling " .. cmd .. " failed ("..se..")")
+			return false
+		end
+		typos = so
 	end
-end
 
-vis:map(vis.modes.NORMAL, "<C-w>a", function(keys)
-	local win = vis.win
-	local file = win.file
-	ret, err = spellcheck(file, { start=0, finish=file.size })
-	if ret then
-		vis:info(err)
+	local corrections_iter = typos:gmatch("(.-)\n")
+	-- skip header line
+	corrections_iter()
+	local index = 0
+	for typo in corrections_iter do
+		if not ignored[typo] then
+			local start, finish = viewport_text:find(typo, index, true)
+			win:style(win.STYLE_INFO, viewport.start + start - 1, viewport.start + finish)
+			index = finish
+		end
 	end
-	win:draw()
+
+	last_viewport = viewport_text
+	last_typos = typos
+	return true
+end)
+
+vis:map(vis.modes.NORMAL, "<C-w>e", function(keys)
+	spellcheck.enabled[vis.win] = true
+	return 0
+end, "Enable spellchecking in the current window")
+
+vis:map(vis.modes.NORMAL, "<C-w>d", function(keys)
+	spellcheck.enabled[vis.win] = nil
+	-- force new highlight
+	vis.win:draw()
 	return 0
-end, "Spellcheck the whole file")
+end, "Disable spellchecking in the current window")
 
 vis:map(vis.modes.NORMAL, "<C-w>w", function(keys)
 	local win = vis.win
 	local file = win.file
-
 	local pos = win.selection.pos
 	if not pos then return end
-	local range = file:text_object_word(pos > 0 and pos-1 or pos);
+	local range = file:text_object_word(pos);
 	if not range then return end
 	if range.start == range.finish then return end
 
-	ret, err = spellcheck(file, range)
-	if ret then
-		vis:info(err)
+	local cmd = spellcheck.cmd:format(spellcheck.lang)
+	local ret, so, se = vis:pipe(win.file, range, cmd)
+	if ret ~= 0 then
+		vis:message("calling " .. cmd .. " failed ("..se..")")
+		return false
+	end
+
+	local suggestions = nil
+	local answer_line = so:match(".-\n(.-)\n.*")
+	local first_char = answer_line:sub(0,1)
+	if first_char == "*" then
+		vis:info(file:content(range).." is correctly spelled")
+		return true
+	elseif first_char == "#" then
+		vis:info("No corrections available for "..file:content(range))
+		return false
+	elseif first_char == "&" then
+		suggestions = answer_line:match("& %S+ %d+ %d+: (.*)")
+	else
+		vis:info("Unknown answer: "..answer_line)
+		return false
+	end
+
+	-- select a correction
+	local cmd = 'printf "' .. suggestions:gsub(", ", "\\n") .. '\\n" | vis-menu'
+	local f = io.popen(cmd)
+	local correction = f:read("*all")
+	f:close()
+	-- trim correction
+	correction = correction:match("%S+")
+	if correction then
+		win.file:delete(range)
+		win.file:insert(range.start, correction)
 	end
 
 	win.selection.pos = pos
@@ -95,12 +124,29 @@ vis:map(vis.modes.NORMAL, "<C-w>w", function(keys)
 	win:draw()
 
 	return 0
-end, "Spellcheck word")
+end, "Correct missspelled word")
+
+vis:map(vis.modes.NORMAL, "<C-w>i", function(keys)
+	local win = vis.win
+	local file = win.file
+	local pos = win.selection.pos
+	if not pos then return end
+	local range = file:text_object_word(pos);
+	if not range then return end
+	if range.start == range.finish then return end
+
+	ignored[file:content(range)] = true
+
+	win:draw()
+	return 0
+end, "Ignore missspelled word")
 
 vis:option_register("spelllang", "string", function(value, toogle)
-	module.lang = value
+	spellcheck.lang = value
 	vis:info("Spellchecking language is now "..value)
+	-- force new highlight
+	last_viewport = nil
 	return true
 end, "The language used for spellchecking")
 
-return module
+return spellcheck