lua: let number increment/decrement handle next number

Operate on the next number to the right of the cursor,
for now the matches are not restricted to the current
line.

Based on a patch from Denis Warsow.

Close martanne#509

lua/plugins/number-inc-dec.lua

@@ -1,52 +1,62 @@
 -- increment/decrement number in dec/hex/oct format
 local lexer = vis.lexers
-if not lexer then return end
+local lpeg = vis.lpeg
+if not lexer or not lpeg then return end
+
+local Cp = lpeg.Cp()
+local dec_num = lpeg.S('+-')^-1 * lexer.dec_num
+local pattern = lpeg.P{ Cp * (lexer.hex_num + lexer.oct_num + dec_num) * Cp + 1 * lpeg.V(1) }
 
 local change = function(delta)
 
 	local win = vis.win
 	local file = win.file
 	local count = vis.count
 	if not count then count = 1 end
-	vis.count = nil -- reset count
+	vis.count = nil -- reset count, otherwise it affects next motion
 
 	for cursor in win:cursors_iterator() do
-		local pos = cursor.pos
-		local word = file:text_object_word(pos);
-		local s, e = word.start, word.finish;
-		if s then
-			local data = file:content(s, e - s)
-			if data and #data > 0 then
-				local base, format, padding = 10, 'd', 0
-				if lexer.oct_num:match(data) then
-					base = 8
-					format = 'o'
-					padding = #data
-				elseif lexer.hex_num:match(data) then
-					base = 16
-					format = 'x'
-					padding = #data - #"0x"
-				end
-				local number = tonumber(data, base == 8 and 8 or nil)
-				if number then
-					number = number + delta * count
-					if base ~= 10 and number < 0 then
-						-- string.format does not handle negative hex/oct values
-						-- should we wrap around?
-						number = 0
-					end
-					number = string.format((base == 16 and "0x" or "") .. "%0"..padding..format, number)
-					if base == 8 and string.sub(number, 0, 1) ~= "0" then
-						number = '0' .. number
-					end
-					file:delete(s, e - s)
-					file:insert(s, number)
-					cursor.pos = s
-				else
-					vis:info("Not a number")
-				end
+		-- poor man's continue statement, use break to process next cursor
+		repeat
+			local pos = cursor.pos
+			if not pos then break end
+			local word = file:text_object_word(pos);
+			if not word then break end
+			local data = file:content(word.start, 1024)
+			if not data then break end
+			local s, e = pattern:match(data)
+			if not s then break end
+			data = string.sub(data, s, e-1)
+			if #data == 0 then break end
+			-- align start and end for fileindex
+			s = word.start + s - 1
+			e = word.start + e - 1
+			local base, format, padding = 10, 'd', 0
+			if lexer.oct_num:match(data) then
+				base = 8
+				format = 'o'
+				padding = #data
+			elseif lexer.hex_num:match(data) then
+				base = 16
+				format = 'x'
+				padding = #data - #"0x"
+			end
+			local number = tonumber(data, base == 8 and 8 or nil)
+			if not number then
+				vis:info("Not a number")
+				break
+			end
+			number = number + delta * count
+			-- string.format does not support negative hex/oct values
+			if base ~= 10 and number < 0 then number = 0 end
+			number = string.format((base == 16 and "0x" or "") .. "%0"..padding..format, number)
+			if base == 8 and string.sub(number, 0, 1) ~= "0" then
+				number = '0' .. number
 			end
-		end
+			file:delete(s, e - s)
+			file:insert(s, number)
+			cursor.pos = s
+		until true
 	end
 end