highlighting, better whitespace, make into a module

1 files changed, 143 insertions, 0 deletions

diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..e393b13
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,143 @@
+local html = require'garkup.html'
+local T = html.T
+local prose = require'garkup.prose'
+
+function empipe(prog, input)
+	local posix = require'posix'
+	local pipe = assert(posix.popen_pipeline({
+		function() io.write(input) end,
+		prog
+	}, "r"))
+	local output = ""
+	repeat
+		local next = assert(posix.unistd.read(pipe.fd, 8192))
+		output = output .. next
+	until #next == 0
+	assert(posix.pclose(pipe))
+	return output
+end
+
+function highlight(code, lang)
+	local highlighted = empipe(
+		{"highlight", "-f", "-S", lang, "--inline-css", "--enclose-pre"},
+		code
+	)
+	return html.safe(highlighted)
+end
+
+local function mode_code(S)
+	local lang = S:line():match("^```(%w+) ?(.*)")
+
+	local text = ""
+	for line in S:lines() do
+		if line:match("^```") then
+			break
+		else
+			text = text .. line
+		end
+	end
+	S:emit(highlight(text, lang))
+end
+
+local function mode_list(S)
+	local items = {}
+	for line in S:lines() do
+		if line:match("^%*") then
+			local content = line:gsub("^%*%s*","")
+			table.insert(items, T.li(prose(S,content)))
+		else
+			S:unline(line)
+			break
+		end
+	end
+	S:emit(T.ul(items))
+end
+
+local function mode_heading(S)
+	local level, line = S:line():match("^#*()%s*(.*)")
+	level = level - 1
+	S:emit(html.tag('h'..level, prose(S,line)))
+end
+
+local mode_patterns = {
+	{ "^```", mode_code },
+	{ "^*", mode_list },
+	{ "^#", mode_heading },
+}
+
+local function match_mode_pattern(S, line)
+	for i, row in ipairs(mode_patterns) do
+		local pattern, mode = row[1], row[2]
+		if line:match(pattern) then return mode end
+	end
+end
+
+local function mode_paragraphs(S)
+	local para = ""
+	local function finish()
+		if para:match("%S") then
+			S:emit(T.p(prose(S,para)))
+		end
+		para = ""
+	end
+
+	for line in S:lines() do
+		local newmode = match_mode_pattern(S, line)
+		if newmode then
+			S:unline(line)
+			finish()
+			return newmode(S)
+		elseif line:match("%S") then
+			para = para .. line
+		else
+			finish()
+		end
+	end
+end
+
+local function split_lines(text)
+	local lines = {}
+	for x in text:gmatch("[^\n]*") do
+		table.insert(lines, x.."\n")
+	end
+	return lines
+end
+
+local State = {}
+function State.new(input)
+	return setmetatable({
+		the_lines = split_lines(input),
+		output = "",
+	}, {__index=State})
+end
+
+function State.emit(self, x)
+	self.output = self.output..tostring(html.html(x)).."\n"
+end
+function State.line(self)
+	return table.remove(self.the_lines, 1)
+end
+function State.unline(self, line)
+	table.insert(self.the_lines, 1, line)
+end
+function State.lines(self)
+	return State.line, self
+end
+function State.remaining(self)
+	return #self.the_lines > 0
+end
+function State.toplevel(self)
+	while self:remaining() do
+		mode_paragraphs(self)
+	end
+	return self.output
+end
+
+local function garkup(text)
+	local S = State.new(text)
+	return S:toplevel(), S
+end
+
+
+-- print(garkup(io.read"a")
+return garkup