initial commit

3 files changed, 293 insertions, 0 deletions

diff --git a/garkup.lua b/garkup.lua
new file mode 100644
index 0000000..2469aa8
--- /dev/null
+++ b/garkup.lua
@@ -0,0 +1,116 @@
+local html = require'html'
+local prose = require'prose'
+
+local function highlight(code)
+	-- todo
+	return html.T.pre(code)
+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))
+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, html.T.li(prose(S,content)))
+		else
+			S:unline(line)
+			break
+		end
+	end
+	S:emit(html.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(html.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)
+	}, {__index=State})
+end
+
+function State.emit(self, x)
+	print(html.html(x))
+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
+end
+
+
+State.new(io.read"a"):toplevel()
diff --git a/html.lua b/html.lua
new file mode 100644
index 0000000..87ecc53
--- /dev/null
+++ b/html.lua
@@ -0,0 +1,87 @@
+local function fmt_attrs(attrs)
+	local function fmt_attr(k,v)
+		if v == true then
+			return k
+		else
+			if type(v) == "table" then v = table.concat(v," ") end
+			return ('%s="%s"'):format(k,v)
+		end
+	end
+
+	local o = ""
+	for k,v in pairs(attrs) do
+		o = o .. " " .. fmt_attr(k,v)
+	end
+	return o
+end
+
+local html
+local function fmt_tag(tag)
+	local attrs = tag.attrs and fmt_attrs(tag.attrs) or ""
+	local selfclosing = (tag.body == "")
+	local sameline = type(tag.body) == "string" or (type(tag.body) == "table" and tag.body.tag)
+	local maybenl = sameline and "" or "\n"
+	if selfclosing then
+		return ("<%s%s/>"):format(tag.tname,attrs)
+	else
+		return ("<%s%s>%s%s</%s>"):format(tag.tname,attrs,maybenl,html(tag.body),tag.tname)
+	end
+end
+
+local function tag(tname, a1, a2)
+	-- tag(tname,body) or tag(tname,attrs,body)
+	local body, attrs
+	if a2 then attrs=a1 body=a2 else attrs=nil body=a1 end
+	return setmetatable({tag=true,tname=tname,attrs=attrs,body=body},{__tostring=fmt_tag})
+end
+
+-- instead of tag('ul', {x, y, z})
+-- you can do T.ul{ x, y, z}
+local T = setmetatable({}, {__index=function(_,tname)
+	return function (...)
+		return tag(tname, ...)
+	end
+end})
+
+local function safe(s)
+	-- marks s as safe, doesn't escape it
+	assert(type(s) == "string","can only mark string as safe")
+	return setmetatable({safe=true,s=s},{__tostring=function(x)return x.s end})
+end
+
+local function escape(s)
+	s=s:gsub("&","&amp;")
+	s=s:gsub("<","&lt;")
+	s=s:gsub(">","&gt;")
+	s=s:gsub('"',"&quot;")
+	return safe(s)
+end
+
+
+html = function (x)
+	if type(x) == "string" then
+		return escape(x)
+	elseif type(x) == "table" then
+		if x.safe then
+			-- safestr. already escaped
+			return x
+		elseif x.tag then
+			-- it's a tag
+			return safe( tostring(x) )
+		else
+			-- just a regular list
+			local o = ""
+			for _,item in ipairs(x) do
+				o = o .. tostring(html(item)) .. "\n"
+			end
+			return safe(o)
+		end
+	end
+end
+
+return {
+	html = html,
+	tag = tag,
+	safe = safe,
+	T = T,
+}
diff --git a/prose.lua b/prose.lua
new file mode 100644
index 0000000..ceadec0
--- /dev/null
+++ b/prose.lua
@@ -0,0 +1,90 @@
+local html = require'html'
+
+local extensions = {}
+
+local function prose(S, text)
+	-- this may be a hack
+	local replacements = {}
+	local SO, SI = "\x0e", "\x0f"
+	-- if debugview then SO,SI = "\x1b[7m", "\x1b[0m" end
+	local function emplace(s)
+		table.insert(replacements, s)
+		return SO .. #replacements .. SI
+	end
+
+	-- no way to match 'after ws or at start of string'
+	-- so, just add ws to start and end of string
+	-- this may also be a hack
+	text = ' ' .. text .. ' '
+
+	local function simple_sub(delim, tagname)
+		return {
+			"(%s)"..delim..'(.-)'..delim..'(%W)', -- wo wimple
+			function(a,x,b) return a..emplace(html.T[tagname](x))..b end
+		}
+	end
+
+	local function extension(str)
+		local verb, rest = str:match("^{(%w+);%s*(.*)}$")
+		if verb then
+			return emplace(extensions[verb](S, rest))
+		end
+		local verbonly = str:match("^{(%w+)}$")
+		if verbonly then
+			return emplace(extensions[verbonly](S))
+		end
+		error("invalid extension syntax: "..str)
+	end
+
+	local subs = {
+		{ "%b{}", extension },
+		simple_sub('%*', 'strong'),
+		simple_sub('_', 'em'),
+		simple_sub('`', 'code'),
+	}
+
+	for i, row in ipairs(subs) do
+		local pattern,replacement = row[1], row[2]
+		text = text:gsub(pattern,replacement)
+	end
+
+	text = text:gsub("^%s*",""):gsub("%s*$","")
+	-- print(text)
+	local insects = {""}
+	local n = 1
+	while n <= #text do
+		local _, nn, id = text:find('^'..SO:gsub("%[","%%[").."(%d+)"..SI:gsub("%[","%%["), n)
+		if nn then
+			table.insert(insects, replacements[tonumber(id)])
+			table.insert(insects, "")
+			n = nn + 1
+		else
+			local c = text:sub(n,n)
+			-- print("'"..c.."'")
+			insects[#insects] = insects[#insects] .. c
+			n = n + 1
+		end
+	end
+
+	-- for i,n in ipairs(insects) do print(i,type(n),n) end
+
+	return insects
+end
+
+extensions.fn = function(S,text)
+	S.footnotes = S.footnotes or {}
+	local n = #S.footnotes + 1
+	local link_id = "fnref_"..n
+	local note_id = "fn_"..n
+	S.footnotes[n] = html.T.li({id=note_id}, {
+		prose(S,text), html.safe"&nbsp;",
+		html.T.a({href="#"..link_id, role="doc-backlink"}, html.safe"&#x21a9;&#xfe0e;")})
+	return html.T.sup({id=link_id}, html.T.a({href="#"..note_id, role='doc-noteref'}, '('..n..')'))
+end
+
+extensions.fns = function(S)
+	if not S.footnotes then return "" end
+	return {html.T.hr{}, html.T.ol(S.footnotes)}
+end
+
+return prose