cortav  Diff

-- [ʞ] cortav.lua
--  ~ lexi hale <lexi@hale.su>
--  © AGPLv3
--  ? renderer

local ct = { render = {} }

local function hexdump(s)
	local hexlines, charlines = {},{}
	for i=1,#s do
		local line = math.floor((i-1)/16) + 1
................................................................................
		return str
	elseif type(o) == "string" then
		return string.format('“%s”', o)
	else
		return tostring(o)
	end
end











local function declare(c)
	local cls = setmetatable({
		__name = c.ident;
	}, {
		__name = 'class';
		__tostring = function() return c.ident or '(class)' end;
................................................................................
	io = ct.exnkind('IO error', function(msg, ...)
		return string.format("<%s %s> "..msg, ...)
	end);
	cli = ct.exnkind 'command line parse error';
	mode = ct.exnkind('bad mode', function(msg, ...)
		return string.format("mode “%s” "..msg, ...)
	end);

}

ct.ctx = declare {
	mk = function(src) return {src = src} end;
	ident = 'context';
	cast = {
		string = function(me)
................................................................................
			new.generation = 1
		end
	end;
	fns = {
		fail = function(self, msg, ...)
			ct.exns.tx(msg, self.src.file, self.line or 0, ...):throw()
		end;




		ref = function(self,id)
			if not id:find'%.' then
				local rid = self.sec.refs[id]
				if self.sec.refs[id] then
					return self.sec.refs[id]
				else self:fail("no such ref %s in current section", id or '') end
			else
................................................................................
	fns = {
		mksec = function(self, id, depth)
			local o = ct.sec(id, depth)
			if id then self.sections[id] = o end
			table.insert(self.secorder, o)
			return o
		end;












































	};
	mk = function() return {
		sections = {};
		secorder = {};
		embed = {};
		meta = {};

	} end;
}

local function map(fn, lst)
	local new = {}
	for k,v in pairs(lst) do
		table.insert(new, fn(v,k))
................................................................................
local function fmtfn(str)
	return function(...)
		return string.format(str, ...)
	end
end

function ct.render.html(doc, opts)

	local f = string.format
	local ids = {}
	local canonicalID = {}
	local function getSafeID(obj)
		if canonicalID[obj] then
			return canonicalID[obj]
		elseif obj.id and ids[obj.id] then
................................................................................
		lisp = { color = 0x77ff88 };
		fortran = { color = 0xff779a };
		python = { color = 0xffd277 };
		python = { color = 0xcdd6ff };
	}

	local stylesets = {















		code = [[
			code {
				background: #000;
				color: #fff;
				font-family: monospace;
				font-size: 90%;
				padding: 3px 5px;
			}
		]];
		abbr = [[
			abbr[title] { cursor: help; }
		]];
		editors_markup = [[]];
		block_code_listing = [[
			section > figure.listing {
				font-family: monospace;
				background: #000;
				color: #fff;
				padding: 0;
				margin: 0.3em 0;
				counter-reset: line-number;
				position: relative;

			}
			section > figure.listing>div {
				white-space: pre-wrap;
				counter-increment: line-number;
				text-indent: -2.3em;
				margin-left: 2.3em;
			}
			section > figure.listing>:is(div,hr)::before {
				width: 1.0em;
				padding: 0.2em 0.4em;
				text-align: right;
				display: inline-block;
				background-color: #333;
				border-right: 1px solid #fff;
				content: counter(line-number);
				margin-right: 0.3em;
			}
			section > figure.listing>hr::before {
				color: #333;
				padding-top: 0;
				padding-bottom: 0;
			}
			section > figure.listing>div::before {
				color: #fff;
			}
			section > figure.listing>div:last-child::before {
				padding-bottom: 0.5em;
			}
			section > figure.listing>figcaption:first-child {
				border: none;
				border-bottom: 1px solid #fff;
			}
			section > figure.listing>figcaption::after {
				display: block;
				float: right;
				font-weight: normal;
				font-style: italic;
				font-size: 70%;
				padding-top: 0.3em;
			}
			section > figure.listing>figcaption {
				font-family: sans-serif;
				font-weight: bold;
				font-size: 130%;
				padding: 0.2em 0.4em;
				border: none;

			}
			section > figure.listing > hr {
				border: none;
				margin: 0;
				height: 0.7em;
				counter-increment: line-number;
			}
................................................................................
				else
					table.insert(text, span_renderers[v.kind](v, block, sec))
				end
			end
			return table.concat(text)
		end

		function span_renderers.format(sp)
			local tags = { strong = 'strong', emph = 'em', strike = 'del', insert = 'ins', literal = 'code' }
			if sp.style == 'literal' and not opts['fossil-uv'] then
				stylesNeeded.code = true
			end
			if sp.style == 'del' or sp.style == 'ins' then
				stylesNeeded.editors_markup = true
			end
			return tag(tags[sp.style],nil,htmlSpan(sp.spans))
		end

		function span_renderers.term(t,b)
			local r = b.origin:ref(t.ref)
			local name = t.ref
			if name:find'%.' then name = name:match '^[^.]*%.(.+)$' end
			if type(r) ~= 'string' then
				b.origin:fail('%s is an object, not a reference', t.ref)
			end
			stylesNeeded.abbr = true
			return tag('abbr',{title=r},next(t.spans) and htmlSpan(t.spans) or name)
		end






























		function span_renderers.link(sp,b)
			local href
			if b.origin.doc.sections[sp.ref] then
				href = '#' .. sp.ref
			else
				if sp.addr then href = sp.addr else
					local r = b.origin:ref(sp.ref)
					if type(r) == 'table' then
						href = '#' .. getSafeID(r)
					else href = r end
				end
			end
			return tag('a',{href=href},next(sp.spans) and htmlSpan(sp.spans) or href)
		end
		return {
			span_renderers = span_renderers;
			htmlSpan = htmlSpan;
			htmlDoc = htmlDoc;
		}
	end
................................................................................
			end
			return lst
		end

		local block_renderers = {
			paragraph = function(b,s)
				return tag('p', nil, sr.htmlSpan(b.spans, b, s), b)









			end;
			label = function(b,s)
				if ct.sec.is(b.captions) then
					local h = math.min(6,math.max(1,b.captions.depth))
					return tag(f('h%u',h), nil, sr.htmlSpan(b.spans, b, s), b)
				else
					-- handle other uses of labels here
................................................................................
					else
						return elt('hr')
					end
				end, b.lines)
				if b.title then
					table.insert(nodes,1,tag('figcaption',nil,sr.htmlSpan(b.title)))
				end
				langsused[b.lang] = true
				return tag('figure', {class='listing', lang=b.lang, id=b.id and getSafeID(b)}, catenate(nodes))
			end;
			['break'] = function() --[[nop]] end;
		}
		return block_renderers;
	end

................................................................................
					end
				end, attrs)) or '')
	end
	local tag = function(t,attrs,body)
		return f('%s%s</%s>', elt(t,attrs), body, t)
	end

	local doctitle
	local ir = {}
	local toc
	local dr = getRenderers(tag,elt,table.concat) -- default renderers
	local plainr = getRenderers(function(t,a,v) return v  end,
	                            function(t,a)   return '' end, table.concat)
	local irBlockRdrs = getBlockRenderers(
		function(t,a,v,o) return {tag = t, attrs = a, nodes = type(v) == 'string' and {v} or v, src = o} end,
................................................................................
	for k in pairs(langsused) do
		local spec = langpairs[k] or {color=0xaaaaaa}
		stylesets.block_code_listing = stylesets.block_code_listing .. string.format(
			[[section > figure.listing[lang="%s"]>figcaption::after
				{ content: '%s'; color: #%06x }]],
			k, spec.name or k, spec.color)
	end



















































	local styles = {}











	for k in pairs(stylesNeeded) do

		table.insert(styles, (stylesets[k]:gsub('%s+',' ')))
	end

	local head = {}
	local styletag = ''
	if opts['link-css'] then
		local css = opts['link-css']
		if type(css) ~= 'string' then ct.exns.mode('must be a string', 'html:link-css'):throw() end
................................................................................
	elseif opts.snippet then
		return styletag .. body
	else
		return dr.htmlDoc(doctitle, next(head) and table.concat(head), body)
	end
end

local function
startswith(str, pfx)
	return string.sub(str, 1, #pfx) == pfx
end

local function eachcode(str, ascode)
	local pos = {
		code = 1;
		byte = 1;
	}
	return function()
		if pos.byte > #str then return nil end
................................................................................
			pos.byte = pos.byte + #utf8.char(thischar)
		end
		pos.code = pos.code + 1
		return thischar, lastpos
	end
end


local function formatter(sty)
	return function(s,c)
		return {
			kind = 'format';
			style = sty;
			spans = ct.parse_span(s, c);
			origin = c:clone();
		}
	end
end























ct.spanctls = {
	{seq = '$', parse = formatter 'literal'};
	{seq = '!', parse = formatter 'emph'};
	{seq = '*', parse = formatter 'strong'};
	{seq = '\\', parse = function(s, c) -- raw
		return s
	end};
	{seq = '$\\', parse = function(s, c) -- raw
		return {
			kind = 'format';
			style = 'literal';
			spans = {s};
			origin = c:clone();
		}
	end};
	{seq = '&', parse = function(s, c)
		local r, t = s:match '^([^%s]+)%s*(.-)$'
		return {
			kind = 'term';
			spans = (t and t ~= "") and ct.parse_span(t, c) or {};
			ref = r; 
			origin = c:clone();
		}
	end};
	{seq = '^', parse = function(s, c)
		local fn, t = s:match '^([^%s]+)%s*(.-)$'
		return {
			kind = 'footnote';
			spans = (t and t~='') and ct.parse_span(t, c) or {};
			ref = fn;
			origin = c:clone();
		}
	end};
	{seq = '>', parse = function(s, c)
		local to, t = s:match '^([^%s]+)%s*(.-)$'
		if not to then c:fail('invalid link syntax >%s', s) end
		if t == "" then t = nil end
		return {
			kind = 'link';
			spans = (t and t~='') and ct.parse_span(t, c) or {};
			ref = to;
			origin = c:clone();




		}
	end};
}

function ct.parse_span(str,ctx)
	local function delimited(start, stop, s)
		local depth = 0
		if not startswith(s, start) then return nil end
		for c,p in eachcode(s) do
			if c == '\\' then
................................................................................
					return s:sub(1+#start, p.byte - #stop), p.byte -- FIXME
				elseif depth < 0 then
					ctx:fail('out of place %s', stop)
				end
			end
		end

		ctx:fail('%s expected before end of line', stop)
	end
	local buf = ""
	local spans = {}
	local function flush()
		if buf ~= "" then
			table.insert(spans, buf)
			buf = ""
................................................................................
	local skip = false
	for c,p in eachcode(str) do
		if skip == true then
			skip = false
			buf = buf .. c
		elseif c == '\\' then
			skip = true
































		elseif c == '[' then
			flush()
			local substr, following = delimited('[',']',str:sub(p.byte))
			p.next.byte = following + p.byte
			local found = false
			for _,i in pairs(ct.spanctls) do
				if startswith(substr, i.seq) then
................................................................................
			c.expand_next = 0
		end
	end;
}

local function insert_table_row(l,c)
	local row = {}
	for kind, a1, text, a2 in l:gmatch '([+|])(:?)%s*([^:+|]*)%s*(:?)' do
		local header = kind == '+'
		local align


		if     a1 == ':' and a2 ~= ':' then









			align = 'left'
		elseif a1 == ':' and a2 == ':' then


			align = 'center'
		elseif a1 ~= ':' and a2 == ':' then

			align = 'right'
		end
		text = text:match '^%s*(.-)%s*$'
		table.insert(row, {




















			spans = ct.parse_span(text, c);
			align = align;
			header = header;
		})
	end
	if #c.sec.blocks > 1 and c.sec.blocks[#c.sec.blocks].kind == 'table' then
		local tbl = c.sec.blocks[#c.sec.blocks]
		table.insert(tbl.rows, row)
	else
		table.insert(c.sec.blocks, {
			kind = 'table';
................................................................................
		})
	end
end

ct.ctlseqs = {
	{seq = '.', fn = insert_paragraph};
	{seq = '¶', fn = insert_paragraph};

	{seq = '#', fn = insert_section};
	{seq = '§', fn = insert_section};
	{seq = '+', fn = insert_table_row};
	{seq = '|', fn = insert_table_row};
	{seq = '│', fn = insert_table_row};
	{pred = function(s,c) return s:match'^[*:]' end, fn = blockwrap(function(l,c) -- list
		local stars = l:match '^([*:]+)'
................................................................................
		local words = function(i)
			local wds = {}
			if i == 0 then return cmdline end
			for w,pos in cmdline:gmatch '([^%s]+)()' do
				table.insert(wds, w)
				i = i - 1
				if i == 0 then

					return table.unpack(wds), cmdline:sub(pos)
				end
			end
		end

		local cmd, rest = words(1)
		if ct.directives[cmd] then
			ct.directives[cmd](words,c)







		elseif crit == '!' then
			c:fail('critical directive %s not supported',cmd)
		end
	end;};
	{seq = '~~~', fn = blockwrap(function(l,c)
		local extract = function(ptn, str)
			local start, stop = str:find(ptn)
................................................................................
			return ex, n
		end
		local lang, id, title
		if l:match '^~~~%s*$' then -- no args
		elseif l:match '^~~~.*~~~%s*$' then -- CT style
			local s = l:match '^~~~%s*(.-)%s*~~~%s*$'
			lang, s = extract('%b[]', s)
			lang = lang:sub(2,-2)
			id, title = extract('#[^%s]+', s)
			if id then id = id:sub(2) end
		elseif l:match '^~~~' then -- MD shorthand style
			lang = l:match '^~~~%s*(.-)%s*$'
		end
		c.mode = {
			kind = 'code';
................................................................................
		end
	end; fn = blockwrap(function()
		return { kind = 'horiz-rule' }
	end)};
	{fn = insert_paragraph};
}

function ct.parse(file, src)
	local function
	is_whitespace(cp)
		return cp == 0x20
	end

	local ctx = ct.ctx.mk(src)
	ctx.line = 0
	ctx.doc = ct.doc.mk()





	ctx.sec = ctx.doc:mksec() -- toplevel section
	ctx.sec.origin = ctx:clone()

	for full_line in file:lines() do ctx.line = ctx.line + 1
		local l
		for p, c in utf8.codes(full_line) do
			if not is_whitespace(c) then
................................................................................
	for k, v in pairs(list) do
		if fn(k,v) then new[k] = v end
	end
	return new
end

local function main(input, output, log, mode, vars)
	local doc = ct.parse(input.stream, input.src)
	input.stream:close()
	if mode['parse:show-tree'] then
		log:write(dump(doc))
	end

	if not mode['render:format'] then
		error 'what output format should i translate the input to?'
	end

	if not ct.render[mode['render:format']] then
		error(string.format('output format “%s” unsupported', mode['render:format']))
	end
	
	local render_opts = kmap(function(k,v)
		return k:sub(2+#mode['render:format'])
	end, kfilter(mode, function(m)
		return startswith(m, mode['render:format']..':')
	end))











	output:write(ct.render[mode['render:format']](doc, render_opts))

end

local inp,outp,log = io.stdin, io.stdout, io.stderr

local function entry_cli()
	local mode, vars, input = default_mode, {}, {
		stream = inp;
................................................................................
		log = function(file)
			local nf = io.open(file,'wb')
			if nf then log:close() log = nf else
				ct.exns.io('could not open log file for writing', 'open',file):throw()
			end
		end;
		define = function(key,value)
			-- set context key



		end;
		mode = function(key,value) mode[checkmodekey(key)] = value end;
		['mode-set'] = function(key) mode[checkmodekey(key)] = true end;
		['mode-clear'] = function(key) mode[checkmodekey(key)] = false end;
	}

	local args = {}
................................................................................
	if args[1] and args[1] ~= '' then
		local file = io.open(arg[1], "rb")
		if not file then error('unable to load file ' .. args[1]) end
		input.stream = file
		input.src.file = args[1]
	end

	main(input, outp, log, mode, vars)
end

-- local ok, e = pcall(entry_cli)
local ok, e = true, entry_cli()
if not ok then
	local str = 'translation failure'



	local color = false
	if log:seek() == nil then
		-- this is not a very reliable heuristic for detecting
		-- attachment to a tty but it's better than nothing
		if os.getenv('COLORTERM') then
			color = true
		else
................................................................................
			local term = os.getenv('TERM')
			if term:find 'color' then color = true end
		end
	end
	if color then
		str = string.format('\27[1;31m%s\27[m', str)
	end
	log:write(string.format('[%s] %s\n\t%s\n', os.date(), str, e))
	os.exit(1)
end

-- [ʞ] cortav.lua
--  ~ lexi hale <lexi@hale.su>
--  © AGPLv3
--  ? reference implementation of the cortav document language

local ct = { render = {} }

local function hexdump(s)
	local hexlines, charlines = {},{}
	for i=1,#s do
		local line = math.floor((i-1)/16) + 1
................................................................................
		return str
	elseif type(o) == "string" then
		return string.format('“%s”', o)
	else
		return tostring(o)
	end
end

local function
lerp(t, a, b)
	return (1-t)*a + (t*b)
end

local function
startswith(str, pfx)
	return string.sub(str, 1, #pfx) == pfx
end

local function declare(c)
	local cls = setmetatable({
		__name = c.ident;
	}, {
		__name = 'class';
		__tostring = function() return c.ident or '(class)' end;
................................................................................
	io = ct.exnkind('IO error', function(msg, ...)
		return string.format("<%s %s> "..msg, ...)
	end);
	cli = ct.exnkind 'command line parse error';
	mode = ct.exnkind('bad mode', function(msg, ...)
		return string.format("mode “%s” "..msg, ...)
	end);
	unimpl = ct.exnkind 'feature not implemented';
}

ct.ctx = declare {
	mk = function(src) return {src = src} end;
	ident = 'context';
	cast = {
		string = function(me)
................................................................................
			new.generation = 1
		end
	end;
	fns = {
		fail = function(self, msg, ...)
			ct.exns.tx(msg, self.src.file, self.line or 0, ...):throw()
		end;
		insert = function(self, block)
			block.origin = self:clone()
			table.insert(self.sec.blocks,block)
		end;
		ref = function(self,id)
			if not id:find'%.' then
				local rid = self.sec.refs[id]
				if self.sec.refs[id] then
					return self.sec.refs[id]
				else self:fail("no such ref %s in current section", id or '') end
			else
................................................................................
	fns = {
		mksec = function(self, id, depth)
			local o = ct.sec(id, depth)
			if id then self.sections[id] = o end
			table.insert(self.secorder, o)
			return o
		end;
		context_var = function(self, var, ctx, test)
			local fail = function(...)
				if test then return false end
				ctx:fail(...)
			end
			if startswith(var, 'cortav.') then
				local v = var:sub(8)
				if v == 'page' then
					if ctx.page then return tostring(ctx.page)
						else return '(unpaged)' end
				elseif v == 'renderer' then
					if not self.stage then
						return fail 'document is not being rendererd'
					end
					return self.stage.format
				elseif v == 'datetime' then
					return os.date()
				elseif v == 'time' then
					return os.date '%H:%M:%S'
				elseif v == 'date' then
					return os.date '%A %d %B %Y'
				elseif v == 'id' then
					return 'cortav.lua (reference implementation)'
				elseif v == 'file' then
					return self.src.file
				else
					return fail('unimplemented predefined variable %s', var)
				end
			elseif startswith(var, 'env.') then
				local v = var:sub(5)
				local val = os.getenv(v)
				if not val then
					return fail('undefined environment variable %s', v)
				end
			elseif self.stage.kind == 'render' and startswith(var, self.stage.format..'.') then
				-- TODO query the renderer somehow
				return fail('renderer %s does not implement variable %s', self.stage.format, var)
			elseif self.vars[var] then
				return self.vars[var]
			else
				if test then return false end
				return '' -- is this desirable behavior?
			end
		end;
	};
	mk = function() return {
		sections = {};
		secorder = {};
		embed = {};
		meta = {};
		vars = {};
	} end;
}

local function map(fn, lst)
	local new = {}
	for k,v in pairs(lst) do
		table.insert(new, fn(v,k))
................................................................................
local function fmtfn(str)
	return function(...)
		return string.format(str, ...)
	end
end

function ct.render.html(doc, opts)
	local doctitle = opts['title']
	local f = string.format
	local ids = {}
	local canonicalID = {}
	local function getSafeID(obj)
		if canonicalID[obj] then
			return canonicalID[obj]
		elseif obj.id and ids[obj.id] then
................................................................................
		lisp = { color = 0x77ff88 };
		fortran = { color = 0xff779a };
		python = { color = 0xffd277 };
		python = { color = 0xcdd6ff };
	}

	local stylesets = {
		accent = [[
			body { background: @bg; color: @fg }
			a[href] {
				color: @tone(0.7 30);
				text-decoration-color: @tone/0.4(0.7 30);
			}
			a[href]:hover {
				color: @tone(0.9 30);
				text-decoration-color: @tone/0.7(0.7 30);
			}
			h1,h2,h3,h4,h5,h6 {
				color: @tone(2);
				border-bottom: 1px solid @tone(0.7);
			}
		]];
		code = [[
			code {
				background: @fg;
				color: @bg;
				font-family: monospace;
				font-size: 90%;
				padding: 3px 5px;
			}
		]];
		abbr = [[
			abbr[title] { cursor: help; }
		]];
		editors_markup = [[]];
		block_code_listing = [[
			section > figure.listing {
				font-family: monospace;
				background: @tone(0.05);
				color: @fg;
				padding: 0;
				margin: 0.3em 0;
				counter-reset: line-number;
				position: relative;
				border: 1px solid @fg;
			}
			section > figure.listing>div {
				white-space: pre-wrap;
				counter-increment: line-number;
				text-indent: -2.3em;
				margin-left: 2.3em;
			}
			section > figure.listing>:is(div,hr)::before {
				width: 1.0em;
				padding: 0.2em 0.4em;
				text-align: right;
				display: inline-block;
				background-color: @tone(0.2);
				border-right: 1px solid @fg;
				content: counter(line-number);
				margin-right: 0.3em;
			}
			section > figure.listing>hr::before {
				color: transparent;
				padding-top: 0;
				padding-bottom: 0;
			}
			section > figure.listing>div::before {
				color: @fg;
			}
			section > figure.listing>div:last-child::before {
				padding-bottom: 0.5em;
			}
			section > figure.listing>figcaption:first-child {
				border: none;
				border-bottom: 1px solid @fg;
			}
			section > figure.listing>figcaption::after {
				display: block;
				float: right;
				font-weight: normal;
				font-style: italic;
				font-size: 70%;
				padding-top: 0.3em;
			}
			section > figure.listing>figcaption {
				font-family: sans-serif;

				font-size: 120%;
				padding: 0.2em 0.4em;
				border: none;
				color: @tone(2);
			}
			section > figure.listing > hr {
				border: none;
				margin: 0;
				height: 0.7em;
				counter-increment: line-number;
			}
................................................................................
				else
					table.insert(text, span_renderers[v.kind](v, block, sec))
				end
			end
			return table.concat(text)
		end

		function span_renderers.format(sp,...)
			local tags = { strong = 'strong', emph = 'em', strike = 'del', insert = 'ins', literal = 'code' }
			if sp.style == 'literal' and not opts['fossil-uv'] then
				stylesNeeded.code = true
			end
			if sp.style == 'del' or sp.style == 'ins' then
				stylesNeeded.editors_markup = true
			end
			return tag(tags[sp.style],nil,htmlSpan(sp.spans,...))
		end

		function span_renderers.term(t,b,s)
			local r = b.origin:ref(t.ref)
			local name = t.ref
			if name:find'%.' then name = name:match '^[^.]*%.(.+)$' end
			if type(r) ~= 'string' then
				b.origin:fail('%s is an object, not a reference', t.ref)
			end
			stylesNeeded.abbr = true
			return tag('abbr',{title=r},next(t.spans) and htmlSpan(t.spans,b,s) or name)
		end

		function span_renderers.macro(m,b,s)
			local r = b.origin:ref(m.macro)
			if type(r) ~= 'string' then
				b.origin:fail('%s is an object, not a reference', t.ref)
			end
			local mctx = b.origin:clone()
			mctx.invocation = m
			return htmlSpan(ct.parse_span(r, mctx),b,s)
		end

		function span_renderers.var(v,b,s)
			local val
			if v.pos then
				if not v.origin.invocation then
					v.origin:fail 'positional arguments can only be used in a macro invocation'
				elseif not v.origin.invocation.args[v.pos] then
					v.origin:fail('macro invocation %s missing positional argument #%u', v.origin.invocation.macro, v.pos)
				end
				val = v.origin.invocation.args[v.pos]
			else
				val = v.origin.doc:context_var(v.var, v.origin)
			end
			if v.raw then
				return val
			else
				return htmlSpan(ct.parse_span(val, v.origin), b, s)
			end
		end

		function span_renderers.link(sp,b,s)
			local href
			if b.origin.doc.sections[sp.ref] then
				href = '#' .. sp.ref
			else
				if sp.addr then href = sp.addr else
					local r = b.origin:ref(sp.ref)
					if type(r) == 'table' then
						href = '#' .. getSafeID(r)
					else href = r end
				end
			end
			return tag('a',{href=href},next(sp.spans) and htmlSpan(sp.spans,b,s) or href)
		end
		return {
			span_renderers = span_renderers;
			htmlSpan = htmlSpan;
			htmlDoc = htmlDoc;
		}
	end
................................................................................
			end
			return lst
		end

		local block_renderers = {
			paragraph = function(b,s)
				return tag('p', nil, sr.htmlSpan(b.spans, b, s), b)
			end;
			directive = function(b,s)
				-- deal with renderer directives
				local _, cmd, args = b.words(2)
				if cmd == 'page-title' then
					if not opts.title then doctitle = args end
				elseif b.critical then
					b.origin:fail('critical HTML renderer directive “%s” not supported', cmd)
				end
			end;
			label = function(b,s)
				if ct.sec.is(b.captions) then
					local h = math.min(6,math.max(1,b.captions.depth))
					return tag(f('h%u',h), nil, sr.htmlSpan(b.spans, b, s), b)
				else
					-- handle other uses of labels here
................................................................................
					else
						return elt('hr')
					end
				end, b.lines)
				if b.title then
					table.insert(nodes,1,tag('figcaption',nil,sr.htmlSpan(b.title)))
				end
				if b.lang then langsused[b.lang] = true end
				return tag('figure', {class='listing', lang=b.lang, id=b.id and getSafeID(b)}, catenate(nodes))
			end;
			['break'] = function() --[[nop]] end;
		}
		return block_renderers;
	end

................................................................................
					end
				end, attrs)) or '')
	end
	local tag = function(t,attrs,body)
		return f('%s%s</%s>', elt(t,attrs), body, t)
	end


	local ir = {}
	local toc
	local dr = getRenderers(tag,elt,table.concat) -- default renderers
	local plainr = getRenderers(function(t,a,v) return v  end,
	                            function(t,a)   return '' end, table.concat)
	local irBlockRdrs = getBlockRenderers(
		function(t,a,v,o) return {tag = t, attrs = a, nodes = type(v) == 'string' and {v} or v, src = o} end,
................................................................................
	for k in pairs(langsused) do
		local spec = langpairs[k] or {color=0xaaaaaa}
		stylesets.block_code_listing = stylesets.block_code_listing .. string.format(
			[[section > figure.listing[lang="%s"]>figcaption::after
				{ content: '%s'; color: #%06x }]],
			k, spec.name or k, spec.color)
	end

	local prepcss = function(css)
		local tone = function(fac, sat, sep, alpha)
			local hsl = function(h,s,l,a)
				local v = string.format('%s, %u%%, %u%%', h,s,l)
				if a then
					return string.format('hsla(%s, %s)', v,a)
				else
					return string.format('hsl(%s)', v)
				end
			end
			sat = sat or 1
			fac = math.max(math.min(fac, 1), 0)
			sat = math.max(math.min(sat, 1), 0)
			if opts.accent then
				local hue = 'var(--accent)'
				local hsep = tonumber(opts['hue-spread'])
				if hsep and sep and sep ~= 0 then
					hue = string.format('calc(%s - %s)', hue, sep * hsep)
				end
				return hsl(hue, math.floor(100*sat), math.floor(100*fac), alpha)
			else
				local g = math.floor(0xFF * fac)
				return string.format('#' .. string.rep('%02x',alpha and 4 or 3), g,g,g,alpha and math.floor(0xFF*alpha))
			end
		end
		local replace = function(var,alpha,param)
			local tonespan = opts.accent and .1 or 0
			local tbg = opts['dark-on-light'] and 1.0 - tonespan or tonespan
			local tfg = opts['dark-on-light'] and tonespan or 1.0 - tonespan
			if var == 'bg' then
				return tone(tbg,nil,nil,tonumber(alpha))
			elseif var == 'fg' then
				return tone(tfg,nil,nil,tonumber(alpha))
			elseif var == 'tone' then
				local l, sep, sat
				for i=1,3 do -- 🙄
					l,sep,sat = param:match('^%('..string.rep('([^%s]*)%s*',i)..'%)$')
					if l then break end
				end
				l = lerp(tonumber(l), tbg, tfg)
				return tone(l, tonumber(sat), tonumber(sep), tonumber(alpha))
			end
		end
		css = css:gsub('@(%w+)/([0-9.]+)(%b())', replace)
		css = css:gsub('@(%w+)(%b())', function(a,b) return replace(a,nil,b) end)
		css = css:gsub('@(%w+)/([0-9.]+)', replace)
		css = css:gsub('@(%w+)', function(a,b) return replace(a,nil,b) end)
		return (css:gsub('%s+',' '))
	end

	local styles = {}
	if opts.width then
		table.insert(styles, string.format([[body {padding:0 1em;margin:auto;max-width:%s}]], opts.width))
	end
	if opts.accent then
		table.insert(styles, string.format(':root {--accent:%s}', opts.accent))
	end
	if opts.accent or (not opts['dark-on-light']) then
		stylesNeeded.accent = true
	end


	for k in pairs(stylesNeeded) do
		if not stylesets[k] then ct.exns.unimpl('styleset %s not implemented (!)',  k):throw() end
		table.insert(styles, prepcss(stylesets[k]))
	end

	local head = {}
	local styletag = ''
	if opts['link-css'] then
		local css = opts['link-css']
		if type(css) ~= 'string' then ct.exns.mode('must be a string', 'html:link-css'):throw() end
................................................................................
	elseif opts.snippet then
		return styletag .. body
	else
		return dr.htmlDoc(doctitle, next(head) and table.concat(head), body)
	end
end






local function eachcode(str, ascode)
	local pos = {
		code = 1;
		byte = 1;
	}
	return function()
		if pos.byte > #str then return nil end
................................................................................
			pos.byte = pos.byte + #utf8.char(thischar)
		end
		pos.code = pos.code + 1
		return thischar, lastpos
	end
end

do -- define span control sequences
	local function formatter(sty)
		return function(s,c)
			return {
				kind = 'format';
				style = sty;
				spans = ct.parse_span(s, c);
				origin = c:clone();
			}
		end
	end
	local function insert_link(s, c)
		local to, t = s:match '^([^%s]+)%s*(.-)$'
		if not to then c:fail('invalid link syntax >%s', s) end
		if t == "" then t = nil end
		return {
			kind = 'link';
			spans = (t and t~='') and ct.parse_span(t, c) or {};
			ref = to;
			origin = c:clone();
		}
	end
	local function insert_var_ref(raw)
		return function(s, c)
			local pos = tonumber(s)
			return {
				kind = 'var';
				pos = pos;
				raw = raw;
				var = not pos and s or nil;
				origin = c:clone();
			}
		end
	end
	ct.spanctls = {
		{seq = '$', parse = formatter 'literal'};
		{seq = '!', parse = formatter 'emph'};
		{seq = '*', parse = formatter 'strong'};
		{seq = '\\', parse = function(s, c) -- raw
			return s
		end};
		{seq = '$\\', parse = function(s, c) -- raw
			return {
				kind = 'format';
				style = 'literal';
				spans = {s};
				origin = c:clone();
			}
		end};
		{seq = '&', parse = function(s, c)
			local r, t = s:match '^([^%s]+)%s*(.-)$'
			return {
				kind = 'term';
				spans = (t and t ~= "") and ct.parse_span(t, c) or {};
				ref = r; 
				origin = c:clone();
			}
		end};
		{seq = '^', parse = function(s, c)
			local fn, t = s:match '^([^%s]+)%s*(.-)$'
			return {
				kind = 'footnote';
				spans = (t and t~='') and ct.parse_span(t, c) or {};
				ref = fn;
				origin = c:clone();
			}
		end};
		{seq = '>', parse = insert_link};








		{seq = '→', parse = insert_link};
		{seq = '🔗', parse = insert_link};
		{seq = '##', parse = insert_var_ref(true)};
		{seq = '#', parse = insert_var_ref(false)};
	}
end


function ct.parse_span(str,ctx)
	local function delimited(start, stop, s)
		local depth = 0
		if not startswith(s, start) then return nil end
		for c,p in eachcode(s) do
			if c == '\\' then
................................................................................
					return s:sub(1+#start, p.byte - #stop), p.byte -- FIXME
				elseif depth < 0 then
					ctx:fail('out of place %s', stop)
				end
			end
		end

		ctx:fail('[%s] expected before end of line', stop)
	end
	local buf = ""
	local spans = {}
	local function flush()
		if buf ~= "" then
			table.insert(spans, buf)
			buf = ""
................................................................................
	local skip = false
	for c,p in eachcode(str) do
		if skip == true then
			skip = false
			buf = buf .. c
		elseif c == '\\' then
			skip = true
		elseif c == '{' then
			flush()
			local substr, following = delimited('{','}',str:sub(p.byte))
			local splitstart, splitstop = substr:find'%s+'
			local id, argstr
			if splitstart then
				id, argstr = substr:sub(1,splitstart-1), substr:sub(splitstop+1)
			else
				id, argstr = substr, ''
			end
			local o = {
				kind = 'macro';
				macro = id;
				args = {};
				origin = ctx:clone();
			}

			do local start = 1
				local i = 1
				while i <= #argstr do
					while i<=#argstr and (argstr:sub(i,i) ~= '|' or argstr:sub(i-1,i) == '\\|') do
						i = i + 1
					end
					local arg = argstr:sub(start, i == #argstr and i or i-1)
					start = i+1
					table.insert(o.args, arg)
					i = i + 1
				end
			end

			p.next.byte = p.next.byte + following - 1
			table.insert(spans,o)
		elseif c == '[' then
			flush()
			local substr, following = delimited('[',']',str:sub(p.byte))
			p.next.byte = following + p.byte
			local found = false
			for _,i in pairs(ct.spanctls) do
				if startswith(substr, i.seq) then
................................................................................
			c.expand_next = 0
		end
	end;
}

local function insert_table_row(l,c)
	local row = {}


	local buf
	local flush = function()
		if buf then table.insert(row, buf) end
		buf = { str = '' }
	end
	for c,p in eachcode(l) do
		if c == '|' or c == '+' and (p.code == 1 or l:sub(p.byte-1,p.byte-1)~='\\') then
			flush()
			buf.header = c == '+'
		elseif c == ':' then
			local lst = l:sub(p.byte-#c,p.byte-#c)
			local nxt = l:sub(p.next.byte,p.next.byte)
			if lst == '|' or lst == '+' and l:sub(p.byte-2,p.byte-2) ~= '\\' then
				buf.align = 'left'

			elseif nxt == '|' or nxt == '|' then
				if buf.align == 'left' then
					buf.align = 'center'

				else
					buf.align = 'right'
				end


			else
				buf.str = buf.str .. c
			end
		elseif c:match '%s' then
			if buf.str ~= '' then buf.str = buf.str .. c end
		elseif c == '\\' then
			local nxt = l:sub(p.next.byte,p.next.byte)
			if nxt == '|' or nxt == '+' or nxt == ':' then
				buf.str = buf.str .. nxt
				p.next.byte = p.next.byte + #nxt
				p.next.code = p.next.code + 1
			else
				buf.str = buf.str .. c
			end
		else
			buf.str = buf.str .. c
		end
	end
	if buf.str ~= '' then flush() end 
	for _,v in pairs(row) do
		v.spans = ct.parse_span(v.str, c)



	end
	if #c.sec.blocks > 1 and c.sec.blocks[#c.sec.blocks].kind == 'table' then
		local tbl = c.sec.blocks[#c.sec.blocks]
		table.insert(tbl.rows, row)
	else
		table.insert(c.sec.blocks, {
			kind = 'table';
................................................................................
		})
	end
end

ct.ctlseqs = {
	{seq = '.', fn = insert_paragraph};
	{seq = '¶', fn = insert_paragraph};
	{seq = '❡', fn = insert_paragraph};
	{seq = '#', fn = insert_section};
	{seq = '§', fn = insert_section};
	{seq = '+', fn = insert_table_row};
	{seq = '|', fn = insert_table_row};
	{seq = '│', fn = insert_table_row};
	{pred = function(s,c) return s:match'^[*:]' end, fn = blockwrap(function(l,c) -- list
		local stars = l:match '^([*:]+)'
................................................................................
		local words = function(i)
			local wds = {}
			if i == 0 then return cmdline end
			for w,pos in cmdline:gmatch '([^%s]+)()' do
				table.insert(wds, w)
				i = i - 1
				if i == 0 then
					table.insert(wds,cmdline:sub(pos))
					return table.unpack(wds)
				end
			end
		end

		local cmd, rest = words(1)
		if ct.directives[cmd] then
			ct.directives[cmd](words,c)
		elseif cmd == c.doc.stage.mode['render:format'] then
			-- this is a directive for the renderer; insert it into the tree as is
			c:insert {
				kind = 'directive';
				critical = crit == '!';
				words = words;
			}
		elseif crit == '!' then
			c:fail('critical directive %s not supported',cmd)
		end
	end;};
	{seq = '~~~', fn = blockwrap(function(l,c)
		local extract = function(ptn, str)
			local start, stop = str:find(ptn)
................................................................................
			return ex, n
		end
		local lang, id, title
		if l:match '^~~~%s*$' then -- no args
		elseif l:match '^~~~.*~~~%s*$' then -- CT style
			local s = l:match '^~~~%s*(.-)%s*~~~%s*$'
			lang, s = extract('%b[]', s)
			if lang then lang = lang:sub(2,-2) end
			id, title = extract('#[^%s]+', s)
			if id then id = id:sub(2) end
		elseif l:match '^~~~' then -- MD shorthand style
			lang = l:match '^~~~%s*(.-)%s*$'
		end
		c.mode = {
			kind = 'code';
................................................................................
		end
	end; fn = blockwrap(function()
		return { kind = 'horiz-rule' }
	end)};
	{fn = insert_paragraph};
}

function ct.parse(file, src, mode)
	local function
	is_whitespace(cp)
		return cp == 0x20
	end

	local ctx = ct.ctx.mk(src)
	ctx.line = 0
	ctx.doc = ct.doc.mk()
	ctx.doc.src = src
	ctx.doc.stage = {
		kind = 'parse';
		mode = mode;
	}
	ctx.sec = ctx.doc:mksec() -- toplevel section
	ctx.sec.origin = ctx:clone()

	for full_line in file:lines() do ctx.line = ctx.line + 1
		local l
		for p, c in utf8.codes(full_line) do
			if not is_whitespace(c) then
................................................................................
	for k, v in pairs(list) do
		if fn(k,v) then new[k] = v end
	end
	return new
end

local function main(input, output, log, mode, vars)
	local doc = ct.parse(input.stream, input.src, mode)
	input.stream:close()
	if mode['parse:show-tree'] then
		log:write(dump(doc))
	end

	if not mode['render:format'] then
		error 'what output format should i translate the input to?'
	end
	if mode['render:format'] == 'none' then return 0 end
	if not ct.render[mode['render:format']] then
		ct.exns.unimpl('output format “%s” unsupported', mode['render:format']):throw()
	end
	
	local render_opts = kmap(function(k,v)
		return k:sub(2+#mode['render:format'])
	end, kfilter(mode, function(m)
		return startswith(m, mode['render:format']..':')
	end))

	doc.vars = vars
	
	-- this is kind of gross but the context object belongs to the parser,
	-- not the renderer, so that's not a suitable place for this information
	doc.stage = {
		kind = 'render';
		format = mode['render:format'];
		mode = mode;
	}

	output:write(ct.render[mode['render:format']](doc, render_opts))
	return 0
end

local inp,outp,log = io.stdin, io.stdout, io.stderr

local function entry_cli()
	local mode, vars, input = default_mode, {}, {
		stream = inp;
................................................................................
		log = function(file)
			local nf = io.open(file,'wb')
			if nf then log:close() log = nf else
				ct.exns.io('could not open log file for writing', 'open',file):throw()
			end
		end;
		define = function(key,value)
			if startswith(key, 'cortav.') or startswith(key, 'env.') then
				ct.exns.cli 'cannot define variable in restricted namespace':throw()
			end
			vars[key] = value
		end;
		mode = function(key,value) mode[checkmodekey(key)] = value end;
		['mode-set'] = function(key) mode[checkmodekey(key)] = true end;
		['mode-clear'] = function(key) mode[checkmodekey(key)] = false end;
	}

	local args = {}
................................................................................
	if args[1] and args[1] ~= '' then
		local file = io.open(arg[1], "rb")
		if not file then error('unable to load file ' .. args[1]) end
		input.stream = file
		input.src.file = args[1]
	end

	return main(input, outp, log, mode, vars)
end

local ok, e = pcall(entry_cli)
-- local ok, e = true, entry_cli()
if not ok then
	local str = 'translation failure'
	if ct.exn.is(e) then
		str = e.kind.desc
	end
	local color = false
	if log:seek() == nil then
		-- this is not a very reliable heuristic for detecting
		-- attachment to a tty but it's better than nothing
		if os.getenv('COLORTERM') then
			color = true
		else
................................................................................
			local term = os.getenv('TERM')
			if term:find 'color' then color = true end
		end
	end
	if color then
		str = string.format('\27[1;31m%s\27[m', str)
	end
	log:write(string.format('%s: %s\n', str, e))
	os.exit(1)
end
os.exit(e)