1 files changed, 124 insertions, 0 deletions
diff --git a/html.lua b/html.lua
new file mode 100644
index 0000000..454eae8
--- /dev/null
+++ b/html.lua
@@ -0,0 +1,124 @@
+-- HTML generator DSL for lua 5.3
+
+-- copyright © 2021 citrons <citrons@mondecitronne.com>
+-- arbitrary copying, distribution, modification, and use is permitted as long
+-- as this copyright notice is retained, and you get in the hole immediately.
+-- go on, get in.
+
+
+local h = {}
+
+local esc_sequences = {
+	["<"] = "&lt;",
+	[">"] = "&gt;",
+	['"'] = "&quot;"
+}
+local function escape(x)
+	local escaped = tostring(x)
+	escaped = escaped:gsub("&", "&amp;")
+
+	for char,esc in pairs(esc_sequences) do
+		escaped = string.gsub(escaped, char, esc)
+	end
+	return escaped
+end
+
+local function render(x)
+	local mt = getmetatable(x)
+	if mt.render then return mt.render(x)
+	else return escape(x) end
+end
+
+local function verify_tag(x)
+end
+
+local meta = {}
+function meta.render(self)
+	local attr_strings = {}
+	local i = 1
+	for k,v in pairs(self.attrs) do
+		verify_tag(k)
+		attr_strings[i] = string.format(' %s="%s"', k, escape(v))
+		i = i + 1
+	end
+	local attrs = table.concat(attr_strings)
+
+	local str
+	if self.children then
+		local child_strings = {}
+		for i,c in ipairs(self.children) do
+			child_strings[i] = render(c)
+		end
+		local children = table.concat(child_strings)
+
+		str = string.format('<%s%s>%s</%s>', 
+				self.tag, attrs, children, self.tag)
+	else
+		str = string.format('<%s%s />', self.tag, attrs)
+	end
+
+	if self.tag == "html" then 
+		str = "<!DOCTYPE html>\n" .. str
+	end
+	return str
+end
+meta.__tostring = meta.render
+
+setmetatable(h, {
+	__index = function(self, tag)
+		verify_tag(tag)
+		return function(...)
+			local attrs, children
+			local args = {...}
+
+			if #args == 2 then 
+				attrs = args[1]
+				if type(args[2]) ~= "table" then 
+					children = {args[2]}
+				else 
+					children = args[2]
+				end
+			elseif #args == 1 then
+				if type(args[1]) ~= "table" then
+					attrs = {} children = {args[1]}
+				elseif args[1][1] ~= nil then
+					attrs = {} children = args[1]
+				else
+					children = {}
+					attrs = {}
+					-- if args[1] is key/value pairs, use it as attributes
+					for _,_ in pairs(args[1]) do
+						children = nil attrs = args[1] break
+					end
+				end
+			else attrs = {} end
+
+			if children then
+				for i,v in ipairs(children) do
+					local mt = getmetatable(v)
+					if mt.tohtml then
+						children[i] = mt.tohtml(v)
+					end
+				end
+			end
+
+			local element = {tag=tag, attrs=attrs, children=children}
+			setmetatable(element, meta)
+			return element
+		end
+	end
+})
+
+local raw_meta = {
+	render = function(self) return self.str end,
+	__tostring = function(self) return self.str end
+}
+
+function h.raw(str)
+	local raw = {str=str}
+	setmetatable(raw, raw_meta)
+	return raw
+end
+
+return h
+