1 files changed, 99 insertions, 0 deletions
diff --git a/html.lua b/html.lua
new file mode 100644
index 0000000..3b34cc3
--- /dev/null
+++ b/html.lua
@@ -0,0 +1,99 @@
+local M = {}
+
+local void = {
+	area = true, base = true, br = true, col = true, embed = true, hr = true,
+	img = true, input = true, link = true, meta = true, param = true,
+	source = true, track = true, wbr = true,
+}
+
+local char_refs = {
+	["<"] = "&lt;",
+	[">"] = "&gt;",
+	['"'] = "&quot;",
+	["&"] = "&amp;",
+}
+local function escape(x)
+	return (tostring(x):gsub('.', char_refs))
+end
+
+local function ele(_, name)
+	assert(name:match '^%w+$')
+	return function(...)
+		local params, inner
+		if select('#', ...) == 2 or type((...)) == 'table' then
+			params, inner = ...
+		else inner = ...  end
+
+		coroutine.yield("<", name)
+		if params then
+			coroutine.yield(" ")
+			for k, v in pairs(params) do
+				assert(not k:find '[%s"\'>/=]')
+				coroutine.yield(k, "=\"", escape(v), "\" ")
+			end
+		end
+		coroutine.yield(">")
+
+		if not void[name] then
+			if type(inner) == 'function' then
+				inner()
+			elseif inner then
+				coroutine.yield(escape(inner))
+			end
+			coroutine.yield("</", name, ">")
+		else
+			assert(not inner)
+		end
+	end
+end
+
+setmetatable(M, {__index = ele})
+
+local function document(fn)
+	return function()
+		coroutine.yield("<!doctype html>")
+		M.html(fn)
+		coroutine.yield("\n")
+	end
+end
+
+function M.render(fn, ...)
+	local output = {}
+
+	local co = coroutine.create(fn, ...)
+	local retvals
+	while true do
+		retvals = {assert(coroutine.resume(co))}
+		if coroutine.status(co) == 'dead' then break end
+		if retvals[2] == abort then
+			coroutine.yield(unpack(retvals))
+		end
+		for i = 2, #retvals do
+			table.insert(output, retvals[i])
+		end
+	end
+
+	return table.concat(output), table.unpack(retvals, 2)
+end
+
+function M.render_doc(fn, ...)
+	return M.render(document(fn), ...)
+end
+
+function M.text(str)
+	coroutine.yield(escape(str))
+end
+
+function M.url_encode(str)
+	return tostring(str):gsub('([^A-Za-z0-9%_%.%-%~])', function(v)
+		return ('%%%02x'):format(v:byte()):upper()
+	end)
+end
+
+function M.url_decode(str)
+	return tostring(str):gsub('%%(%x%x)', function(c)
+		return string.char(tonumber(c, 16))
+	end)
+end
+
+return M