diff --git a/pret-pas.lua b/pret-pas.lua
index 0288327..6e4145f 100644
--- a/pret-pas.lua
+++ b/pret-pas.lua
@@ -98,7 +98,8 @@ end
 end]]
 
 function visualizer.flush_line(str, nested)
-    local state, word = 0, nil
+    local state, word, lastc = 0, nil, nil
+	local incomment = false
     buffers.currentcolors = colors
 
 --[[
@@ -116,6 +117,7 @@ function visualizer.flush_line(str, nested)
 ]]
 
 	--state = buffers.changestate(1, state)
+	--TODO: handle inlongcomment etc.
 	for c in string.utfcharacters(str) do
 		if string.find(c, "^[%a_]$") then
 			-- char belongs to identifier
@@ -130,31 +132,64 @@ function visualizer.flush_line(str, nested)
 				word = word .. c
 			else
 				-- number
-				state = buffers.changestate(3, state)
+				if not incomment then
+					state = buffers.changestate(3, state)
+				end
 				tex.write(c)
 			end
 		else
+			if not incomment then
+				state = buffers.finishstate(state)
+			end
 			flush_pas_word(word)
 			word = nil
 			if c == " " then
-				state = buffers.finishstate(state)
+				--state = buffers.finishstate(state)
 				tex.sprint(tex.ctxcatcodes, "\\obs")
 			elseif c == "\t" then
-				state = buffers.finishstate(state)
+				--state = buffers.finishstate(state)
 				tex.sprint(tex.ctxcatcodes, "\\obs")
 				if buffers.visualizers.enabletab then
 					tex.sprint(tex.ctxcatcodes,rep("\\obs ", buffers.visualizers.tablength))
 				end
+			elseif c == "/" then
+				if lastc == "/" then
+					if not incomment then
+						-- one-line comment starts
+						incomment = true
+						state = buffers.changestate(3, state)
+						tex.sprint(tex.ctxcatcodes, "\{\\bf")
+					end
+					tex.write("//")
+				end
+			elseif c == "{" then
+				if not incomment then
+					-- long comment starts
+					incomment = true
+					inlongcomment = true
+					state = buffers.changestate(3, state)
+					tex.sprint(tex.ctxcatcodes, "\{\\bf")
+				end
+				tex.write(c)
+			-- TODO: (*, asm, {$, '
 			else
 				-- symbol
-				state = buffers.changestate(1, state)
+				if not incomment then
+					state = buffers.changestate(1, state)
+				end
 				tex.write(c)
 			end
 		end
+		lastc = c
+	end
+	if not incomment then
 		state = buffers.finishstate(state)
 	end
 	flush_pas_word(word)
-	word = nil
+	if incomment then
+		tex.sprint(tex.ctxcatcodes, "\}")
+	end
+	--word = nil
 	
 --[[
     local code, comment = string.match(str,"^(.-)%-%-%[%[(.*)$")