Index: cortav.lua
==================================================================
--- cortav.lua
+++ cortav.lua
@@ -143,18 +143,20 @@
 				end)
 
 			end
 
 			local function checkFromSec(sec,doc)
-				if sec and not id:find'%.' then
-					local rid = sec.refs[id]
-					if rid then
-						return rid, id, sec
+				if not id:find'%.' then
+					if sec then
+						local rid = sec.refs[id]
+						if rid then
+							return rid, id, sec
+						end
 					end
 
-					if doc.sections[rid] then
-						return nil, id, doc.sections[rid]
+					if doc.sections[id] then
+						return nil, id, doc.sections[id]
 					end
 				else
 					local secid, ref = string.match(id, "(.-)%.(.+)")
 					local s
 					s = s or doc.sections[secid]
@@ -198,11 +200,11 @@
 						return rid, id, self.invocation.origin.sec
 					end
 				end
 			end
 
-			o,i,s = scanParents(doc)
+			o,i,s = scanParents(self.doc)
 			if o or s then return o,i,s end
 
 			self:fail("ID “%s” does not name an object or section", id)
 		end
 	};

Index: render/html.lua
==================================================================
--- render/html.lua
+++ render/html.lua
@@ -613,19 +613,49 @@
 		function span_renderers.raw(v,b,s)
 			return htmlSpan(v.spans, b, s)
 		end
 
 		function span_renderers.link(sp,b,s)
+			local dest_o, _, dest_s = b.origin:ref(sp.ref)
 			local href
-			if b.origin.doc.sections[sp.ref] then
-				href = '#' .. getSafeID(sp)
+			if dest_o == nil then
+				-- link is to the section itself
+				href = '#' .. getSafeID(dest_s)
 			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
+-- 				if sp.addr then href = sp.addr else
+				if type(dest_o) == 'table' then
+					href = '#' .. getSafeID(dest_o)
+				else -- URI in reference
+					local uri = ss.uri(dest_o)
+					if uri.class[1] == 'file'
+					or uri.class[1] == 'asset' then
+						if uri.namespace == 'localhost' then
+							-- emit an actual file url
+							href = 'file://' .. uri:construct('path','frag')
+						elseif uri.namespace == nil then
+							-- this is gonna be tricky. first we establish the location
+							-- of the CWD/asset base relative to the output file (if any;
+							-- assume equivalent otherwise) then express the difference
+							-- as a directory prefix.
+							-- jk tho for now we just emit the path+frag sadlol TODO
+							href = uri:construct('path','frag')
+						else
+							b.origin:fail('file: URI namespace must be empty or “localhost” for HTML links; others are not meaningful (offending URI: “%s”)', dest_o)
+						end
+					elseif uri:canfetch() == 'http' then
+						local sc = 'http'
+						if uri.class[1] == 'https' or uri.class[2] == 'tls' then
+							sc = 'https'
+						end
+						if uri.namespace == nil and uri.auth == nil and uri.svc == nil then
+							-- omit the scheme so we can use a relative path
+							href = uri:construct('path','query','frag')
+						else
+							uri.class = {sc}
+							href = tostring(uri)
+						end
+					else href = tostring(uri) end
 				end
 			end
 			return tag('a',{href=href},next(sp.spans) and htmlSpan(sp.spans,b,s) or href)
 		end
 

Index: sirsem.lua
==================================================================
--- sirsem.lua
+++ sirsem.lua
@@ -763,13 +763,13 @@
 	};
 }
 
 function ss.classinstance(o)
 	local g = getmetatable(o)
-	if not o then return nil end
+	if not g then return nil end
 	local mm = getmetatable(g)
-	if not o then return nil end
+	if not mm then return nil end
 	if mm.__name == 'class' then
 		return g
 	else
 		return nil
 	end
@@ -1216,10 +1216,121 @@
 	for i = 1, #a do
 		if not eq(a[i],b[i]) then return false end
 	end
 	return true
 end
+
+ss.os = {}
+function ss.os.getcwd()
+	return os.getenv 'PWD' -- :((( HAX
+end
+
+ss.path = ss.declare {
+	ident = 'path';
+	mk = function() return {
+		relative = true;
+		elts = {};
+	} end;
+	construct = function(me, o, rel)
+		if type(o) == 'string' then
+			if o:sub(1,1) == '/' then
+				me.relative = false
+			end
+			me.elts = ss.str.split(ss.str.enc.ascii, o, '/')
+		elseif type(o) == 'table' then
+			me.elts = o
+			me.relative = rel
+		end
+	end;
+	clonesetup = function(me)
+		me.elts = ss.clone(me.elts)
+	end;
+	cast = {
+		string = function(me)
+			return (me.relative and '' or '/') ..
+				table.concat(me.elts, '/')
+		end;
+	};
+	op = {
+		sub = function(a,b)
+			if a.relative ~= b.relative then
+				return nil
+			end
+
+			local np = ss.path({}, true)
+			local brk = false
+			for i=1, math.max(#a.elts,#b.elts) do
+				if not brk then
+					if a.elts[i] ~= b.elts[i] then
+						brk = true
+					end
+				end
+				if brk then
+					table.insert(np.elts, b.elts[i])
+				end
+			end
+
+			return np
+		end;
+		sum = function(a,b)
+			if b.relative == false then
+				return nil
+			end
+			local n = a:clone()
+			local i = #n.elts
+			for j, v in ipairs(b.elts) do
+				n.elts[i+j] = v
+			end
+			return n
+		end;
+		lt = function(a,b)
+			-- '/a/b/c' < '/a/b/c/d'
+			-- 'q/f/g' < 'q/f/g/p/d'
+			-- '/a' !< '/b', '/a' !< 'a'
+			if a.relative ~= b.relative then
+				return false
+			end
+			if #a.elts > #b.elts then return false end
+			for i=1, #a.elts do
+				if a.elts[i] ~= b.elts[i] then
+					return false
+				end
+			end
+			return true
+		end;
+	};
+	fns = {
+		dir = function(me)
+			local n = ss.copy(me.elts)
+			n[#n] = nil
+			local p = ss.path(n, me.relative)
+		end;
+		normalize = function(me)
+			local np = ss.path({}, me.relative)
+			for i, e in ipairs(me.elts) do
+				if e == '..' then
+					if me.relative and (
+						next(np.elts) == nil or
+						np.elts[#np.elts] == '..'
+					) then
+						table.insert(np.elts, '..')
+					else
+						table.remove(np.elts)
+					end
+				elseif e ~= '.' then
+					table.insert(np.elts, e)
+				end
+			end
+			return np
+		end
+	};
+	cfns = {
+		cwd = function()
+			return ss.path(ss.os.getcwd())
+		end;
+	};
+}
 
 ss.uri = ss.declare {
 	ident = 'uri';
 	mk = function() return {
 		class = nil;
@@ -1244,11 +1355,11 @@
 		end
 		if not rem then
 			ss.uri.exn('invalid URI “%s”', str):throw()
 		end
 		local s_ns do
-			local s,r = rem:match '^//([^/]*)(.*)$'
+			local s,r = rem:match '^//([^/?#]*)(.*)$'
 			if s then s_ns, rem = s,r end
 		end
 		local h_query
 		local s_frag
 		local s_path if rem ~= '' then
@@ -1305,10 +1416,33 @@
 		me.query = dec(s_query)
 		me.frag = dec(s_frag)
 	end;
 	cast = {
 		string = function(me)
+			return me:construct('class','namespace','path','query','frag')
+		end;
+	};
+	fns = {
+		canfetch = function(me)
+			for id, pr in pairs(fetchableProtocols) do
+				for _, p in ipairs(pr.proto) do
+					if ss.match(me.class, p) then return id end
+				end
+			end
+			return false
+		end;
+		construct = function(me, ...)
+			local parts = {}
+			local function add(n, ...)
+				if n == nil then return end
+				table.insert(parts, me:part(n))
+				add(...)
+			end
+			add(...)
+			return table.concat(parts)
+		end;
+		part = function(me, p)
 			local function san(str, chars)
 				-- TODO IRI support
 				chars = chars or ''
 				local ptn = '-a-zA-Z0-9_.,;'
 				ptn = ptn .. chars
@@ -1315,51 +1449,43 @@
 				return (str:gsub('[^'..ptn..']', function(c)
 					if c == ' ' then return '+' end
 					return string.format('%%%02X', string.byte(c))
 				end))
 			end
-			if me.class == nil or next(me.class) == nil then
-				return 'none:'
-			end
-			local parts = {
-				table.concat(ss.map(san,me.class), '+') .. ':';
-			}
-			if me.namespace or me.auth or me.svc then
-				table.insert(parts, '//')
-				if me.auth then
-					table.insert(parts, san(me.auth,':') .. '@')
+			if p == 'class' then
+				if me.class == nil or next(me.class) == nil then
+					return 'none:'
 				end
-				if me.namespace then
-					table.insert(parts, san(me.namespace))
-				end
-				if me.svc then
-					table.insert(parts, ':' .. san(me.svc))
-				end
-				if me.path and not ss.str.begins(me.path, '/') then
-					table.insert(parts, '/')
+				return table.concat(ss.map(san,me.class), '+') .. ':';
+			else
+				if me[p] == nil then return '' end
+				if p == 'namespace' then
+					local parts = {}
+					if me.namespace or me.auth or me.svc then
+						table.insert(parts, '//')
+						if me.auth then
+							table.insert(parts, san(me.auth,':') .. '@')
+						end
+						if me.namespace then
+							table.insert(parts, san(me.namespace))
+						end
+						if me.svc then
+							table.insert(parts, ':' .. san(me.svc))
+						end
+						if me.path and not ss.str.begins(me.path, '/') then
+							table.insert(parts, '/')
+						end
+					end
+					return table.concat(parts)
+				elseif p == 'path' then
+					return san(me.path,'+/=&')
+				elseif p == 'query' then
+					return '?' .. san(me.query,'?+/=&')
+				elseif p == 'frag' then
+					return '#' .. san(me.frag,'+/=&')
 				end
 			end
-			if me.path then
-				table.insert(parts, san(me.path,'+/=&'))
-			end
-			if me.query then
-				table.insert(parts, '?' .. san(me.query,'?+/=&'))
-			end
-			if me.frag then
-				table.insert(parts, '#' .. san(me.frag,'+/=&'))
-			end
-			return table.concat(parts)
-		end;
-	};
-	fns = {
-		canfetch = function(me)
-			for id, pr in pairs(fetchableProtocols) do
-				for _, p in ipairs(pr.proto) do
-					if ss.match(me.class, p) then return id end
-				end
-			end
-			return false
 		end;
 		fetch = function(me, env)
 			local pid = me:canfetch()
 			if (not pid) or fetchableProtocols[pid].fetch == nil then
 				ss.uri.exn("URI “%s” is unfetchable", tostring(me)):throw()