util  Diff

		if src == nil then return end
		local sc = #src
		for j=1,sc do dest[i+j] = src[j] end
		i = i + sc
		iter(...)
	end
	iter(...)







end
local function tcat(...)
	local new = {}
	tcatD(new, ...)
	return new
end
local ansi = {
................................................................................
		decode = function(s)
			local n = parse(ty,s)
			if (n+1) > #vals then error(string.format('enum "%s" does not have %u members', table.concat(vals,'","'),n),3) end
			return vals[n+1]
		end;
	}
end









fmt.note = {
	{'kind', fmt.tag};
	{'paras', fmt.list(fmt.string)};
}

fmt.example = {
	{'quote',fmt.string};
	{'src',fmt.label};
}

fmt.meaning = {
	{'lit', fmt.string};
	{'examples', fmt.list(fmt.example,fmt.u8)};
	{'notes', fmt.list(fmt.note,fmt.u8)};
}

fmt.phrase = {
	{'str',fmt.label};
	{'means',fmt.list(fmt.meaning,fmt.u8)};
	{'xref',fmt.list(fmt.path,fmt.u16)};
}

fmt.def = {
	{'part', fmt.u8};
	{'branch', fmt.list(fmt.label,fmt.u8)};
	{'means', fmt.list(fmt.meaning,fmt.u8)};
	{'forms', fmt.map(fmt.u16,fmt.label,fmt.u16)};
	{'phrases', fmt.list(fmt.phrase,fmt.u16)};
}

fmt.word = {
	{'defs', fmt.list(fmt.def,fmt.u8)};
}

fmt.dictHeader = {
	{'lang', fmt.tag};
	{'meta', fmt.string};
	{'partsOfSpeech', fmt.list(fmt.tag,fmt.u16)};
................................................................................
		{'parts', fmt.list(fmt.tag,fmt.u8)};
		-- which parts of speech does this form apply to?
		-- leave empty if not relevant
	},fmt.u16)};
}

fmt.relSet = {
	{'uid', fmt.u32};
		-- IDs are persistent random values so they can be used
		-- as reliable identifiers even when merging exports in
		-- a parvan-unaware VCS
	{'members', fmt.list(fmt.path,fmt.u16)};
	{'kind', fmt.enum('syn','ant','met')};


}

fmt.dict = {
	{'header', fmt.dictHeader};
	{'words', fmt.map(fmt.string,fmt.word)};
	{'relsets', fmt.list(fmt.relSet)};
}
................................................................................
end

local function rebuildRelationCache(d)
-- (re)build a dictionary's relation cache; needed
-- at load time and whenever any changes to relsets
-- are made (unless they're simple enough to update
-- the cache directly by hand, but that's very eeeh)
	local sc = {}
	for i,s in ipairs(d.relsets) do
		for j,m in ipairs(s.members) do
			sc[m.w] = sc[m.w] or {}
			table.insert(sc[m.w], s)
		end
	end



















	d._relCache = sc
end

local function
writeDict(d)
	local atomizePoS, posMap = atomizer()
	for lit,w in pairs(d.words) do
		for j,def in ipairs(w.defs) do
................................................................................
		if not fd then error(userError("cannot open file " .. file),2) end
		return fd
	else
		return file
	end
end

local function
safeNavWord(ctx, word, dn, mn, nn)
	local w = ctx.dict.words[word]
	if not w then id10t 'bad word' end
	if dn == nil then return w end

	local d = w.defs[tonumber(dn)]
	if not d then id10t('no definition #%u',dn) end
	if mn == nil then return w,d end

	local m = d.means[tonumber(mn)]
	if not m then id10t('no meaning #%u',mn) end
	if nn == nil then return w,d,m end

	local n = m.notes[tonumber(nn)]
	if not n then id10t('no note #%u',nn) end
	return w,d,m,n
end

local function copy(tab)
	local new = {}
	for k,v in pairs(tab) do new[k] = v end
	return new
end

local function pathParse(p)
................................................................................
		and a.dn == b.dn
		and a.mn == b.mn
		and a.pn == b.pn
		and a.nn == b.nn
		and a.xn == b.xn
end
local function pathResolve(ctx, a)


	if not a.w then return end -- empty paths are valid!
	local function lookup(seg, tbl,val)
		if not tbl then error('bad table',2) end
		local v = tbl[val]
		if v then return v end
		id10t('bad %s in path: %s', seg, val)
	end

	local res = {}
	res.word = lookup('word', ctx.dict.words, a.w)
	if not a.dn then return res end

	res.def = lookup('definition', w.defs, a.dn)
	if (not a.pn) and (not a.mn) then return res end

	local m if a.pn then
		res.phrase = lookup('phrase', d.phrases, a.pn)
		res.meaning = lookup('meaning', p.means, a.mn)
	else
		res.meaning = lookup('meaning', d.means, a.mn)
	end

	if a.xn then
		res.ex = lookup('example',m.examples,a.xn)
	elseif a.nn then
		res.note = lookup('note',m.notes,a.nn)
	end

	return res
end

local function pathNav(...)
	local t = pathResolve(...)
................................................................................
		help = "add a new word";
		syntax = "<word>";
		write = true;
		exec = function(ctx,word)
			if ctx.dict.words[word] then
				id10t "word already coined"
			end
			ctx.dict.words[word] = {defs={}}
		end;
	};
	def = {
		help = "define a word";
		syntax = "<word> <part-of-speech> [<meaning> [<root>…]]";
		write = true;
		exec = function(ctx,word,part,means,...)
			local etym = {...}
			if (not word) or not part then
				id10t 'bad definition'
			end
			if not ctx.dict.words[word] then
				ctx.dict.words[word] = {defs={}}
			end
			local n = #(ctx.dict.words[word].defs)+1
			ctx.dict.words[word].defs[n] = {
				part = part;
				branch = etym;
				means = {means and {
					lit=means;
					examples={};
					notes={};

				} or nil};
				forms = {};


			}
			ctx.log('info', string.format('added definition #%u to “%s”', n, word))
		end;
	};
	mean = {
		help = "add a meaning to a definition";
		syntax = "<word> <def#> <meaning>";
................................................................................
				end
				local links={}
				for i,l in ipairs{select(2,...)} do
					links[i] = pathParse(l)
				end
				local newstruct = {
					uid=math.random(1,0xffffFFFF);
					members=links;
					kind = rel;
				}
				table.insert(ctx.dict.relsets, newstruct)

				local rc = ctx.dict._relCache
				for i,l in pairs(links) do
					rc[l.w] = rc[l.w] or {}
					table.insert(rc[l.w], newstruct)
				end
				rebuildRelationCache(ctx.dict)
			else -- assemble a list of groups
				local tgtw = ...
				local wp = pathParse(tgtw)
				local w,d,m = pathNav(ctx, wp)

				for i,ss in ipairs(ctx.dict.relsets) do

					for j,s in ipairs(ss.members) do
						if pathSub(s, wp) then
-- 						if s.word == wp.w and (wp.dn == nil or s.def == wp.dn) then
							table.insert(groups, {set = ss, mem = s, id = i})








							break
						end
					end
				end

				if op == 'show' then
					for i, g in ipairs(groups) do
................................................................................
								end
							end

							return repr
						end

						local others = {}
						for j, o in ipairs(g.set.members) do

							local ow = pathResolve(ctx, {w=o.w}).w
							if (g.set.kind == 'ant' or not pathMatch(o, g.mem)) and
								--exclude antonym headwords
								not (g.set.kind == 'ant' and j==1) then
								table.insert(others, '      '..label(o,ow))
							end
						end
						local llab do
							local cdw = ctx.dict.words
							if g.set.kind == 'ant' then
								local ap = g.set.members[1]
								llab = fo.br(label(ap,cdw[ap.w]) or '')
							else
								llab = fo.br(label(g.mem,cdw[g.mem.w]) or '')
							end
						end
						local kls = {
							syn = fo.color('synonyms',2,true)..' of';
							ant = fo.color('antonyms',1,true)..' of';
							met = fo.color('metonyms',4,true)..' of';
						}
................................................................................
					local tgtn, paths = (select(2,...)), { select(3, ...) }
					rebuildRelationCache(ctx.dict)
				elseif op == 'destroy' then
					local tgtw, tgtn = ...
					if not tgtn then id10t 'missing group number' end
					local delendum = groups[tonumber(tgtn)]
					if not delendum then id10t 'bad group number' end
					local rs = ctx.dict.relsets
					local last = #rs
					if delendum.id == last then
						rs[delendum.id] = nil
					else -- since order doesn't matter, we can use a
						-- silly swapping trick to reduce the deletion
						-- worst case from O(n) to O(2)
						rs[delendum.id] = rs[last]
						rs[last] = nil
					end
					rebuildRelationCache(ctx.dict)
				else
					id10t 'invalid operation'
				end
			end
		end;
	};
................................................................................
		help = "add a note to a definition or a paragraph to a note";
		syntax = {"(<m-path> (add|for) <kind> | <m-path>:<note#>) <para>…";
			"m-path ::= <word>@<def#>/<meaning#>"};
		write = true;
		exec = function(ctx,path,...)
			local paras, mng
			local dest = pathParse(path)
			local _,_,m = safeNavWord(ctx,dest.w,dest.dn,dest.mn)
			if dest.nn then
				paras = {...}
			else
				local op, kind = ...
				paras = { select(3, ...) }
				if op == 'add' then
					dest.nn = #(m.notes) + 1
					m.notes[dest.nn] = {kind=kind, paras=paras}
					return
				elseif op == 'for' then
					for i,nn in ipairs(m.notes) do
						if nn.kind == kind then
							dest.nn = i break
						end
					end
					if not dest.nn then
						id10t('no note of kind %s in %s',kind,path)
					end
				end
			end
			local dpa = m.notes[dest.nn].paras
			local top = #dpa
			for i,p in ipairs(paras) do
				dpa[top+i] = p
			end
		end
	};
	shell = {
................................................................................
		end
	end
	table.sort(out, function(a,b) return a.lit < b.lit end)
	local fo = ctx.sty[io.stdout]

	local function gatherRelSets(path)
		local antonymSets, synonymSets, metonymSets = {},{},{}
		if ctx.dict._relCache[path.w] then
			for i, rel in ipairs(ctx.dict._relCache[path.w]) do

				local specuset,tgt,anto = {}

				for j, mbr in ipairs(rel.members) do
					if pathMatch(mbr, path) then
						if     rel.kind == 'syn' then tgt = synonymSets
						elseif rel.kind == 'met' then tgt = metonymSets
						elseif rel.kind == 'ant' then
							if j == 1 -- is this the headword?
								then tgt = antonymSets
								else tgt = synonymSets
							end
						end
					elseif j == 1 and rel.kind == 'ant' then
						anto = mbr
					else
						table.insert(specuset, mbr)
					end
				end
				if tgt then
					table.insert(tgt, specuset)
					if anto then
						table.insert(antonymSets, {anto})
					end
................................................................................
	end
	for i, w in ipairs(out) do
		local d = fo.ul(fo.br(w.lit))
		local wordrels = autobreak(table.concat(
				formatRels(gatherRelSets{w=w.lit}, 2),
				'\n'
			))
		local wc = ctx.dict._relCache[w.lit]
		if #w.word.defs == 1 then
			d=d .. ' '
			    .. fo.rgb(fo.em('('..(w.word.defs[1].part)..')'),.8,.5,1) .. '\n'
			    .. meanings(w,w.word.defs[1],false,1) .. '\n'
			    .. autobreak(table.concat(formatRels(gatherRelSets{w=w.lit,dn=1}, 4), '\n'))
				 .. wordrels .. '\n'
		else
................................................................................
				if c ~= 'pv0' then
					id10t "not a parvan export"
				end
				new.header.lang = words[2]
				new.header.meta = words[3]
				state = 1
			else
				print(pathString(path, ctx.sty[io.stderr]))
				local W,D,M,N = pathNav({dict=new}, path)







				if c == 'w' then syn(1) state = 2
					path = {w=words[2]}
					new.words[words[2]] = {defs={}}
				elseif c == 'f' then syn(1)
					local nf = {
						name = words[2];
						abbrev = words[3] or "";
						desc = words[4] or "";
						parts = {};
					}
................................................................................
					table.insert(lastinfl.parts,words[2])
				elseif c == 's' then syn(2)
					relsets[words[3]] = relsets[words[3]] or {}
					relsets[words[3]].kind = words[2]
					relsets[words[3]].uid = tonumber(words[3])
					relsets[words[3]].members = relsets[words[3]].members or {}
				elseif state >= 2 and c == 'r' then syn(1)










					relsets[words[2]] = relsets[words[2]] or {
						uid = tonumber(words[2]);
						members={};
					}
					table.insert(relsets[words[2]].members, path)
				elseif state >= 2 and c == 'd' then syn(1) state = 3
					table.insert(W.defs, {
						part = words[2];
						branch = {};
						means = {};
						forms = {};
						phrases = {};

					})
					path = {w = path.w, dn = #(W.defs)}
				elseif state >= 3 and c == 'dr' then syn(1)
					table.insert(D.branch, words[2])
				elseif state >= 3 and c == 'df' then syn(2)
					if not inflmap[words[2]] then
						id10t('no inflection form %s defined', words[2])
					end
					D.forms[inflmap[words[2]]] = words[3]







				elseif state >= 3 and c == 'm' then syn(1) state = 4
					table.insert(D.means, {
						lit = words[2];
						notes = {};
						examples = {};

					});
					path = {w = path.w, dn = path.dn, mn = #(D.means)}
				elseif state >= 4 and c == 'n' then syn(1) state = 5
					table.insert(M.notes, {kind=words[2], paras={}})
					path = {w = path.w, dn = path.dn, mn = path.mn, nn = #(M.notes)};
				elseif state >= 5 and c == 'np' then syn(1)
					table.insert(N.paras, words[2])
				end
				-- we ignore invalid ctls, for sake of forward-compat
			end
		end
	end
................................................................................

	for k,v in pairs(relsets) do
		if not v.uid then
			--handle non-numeric export ids
			v.uid = math.random(0,0xffffFFFF)
		end
		table.insert(new.relsets, v)




	end

	local ofd = safeopen(ctx.file,"w+b")
	local o = writeDict(new);
	ofd:write(o)
	ofd:close()
end
................................................................................
		if ctx.flags.human and lvl > 0 then
			pfx = string.rep('\t', lvl)
		end
		ofd:write(pfx..string.format(...)..'\n')
	end
	local d = ctx.dict
	o(0,'pv0 %s %s', san(d.header.lang), san(d.header.meta))
	local function checksyn(obj)
-- 		for _,s in ipairs(d.synonyms) do
		local lvl = 0
		if     obj.nn then lvl = 4
		elseif obj.mn then lvl = 3
		elseif obj.dn then lvl = 2
		elseif obj.w  then lvl = 1 end
		if not d._relCache[obj.w] then return end
		for _,s in ipairs(d._relCache[obj.w]) do
			for _,sm in ipairs(s.members) do
				if pathMatch(obj, sm) then
					o(lvl,'r %u',s.uid)
					break
				end
			end
		end
	end
	for i,f in pairs(d.header.inflectionForms) do
		o(0,'f %s %s %s', san(f.name), san(f.abbrev), san(f.desc))
		for j,p in pairs(f.parts) do
			o(1,'fp %s', san(p))
		end














	end
	for lit, w in pairs(d.words) do
		o(0,'w %s',san(lit))
		checksyn{w=lit}
		for i,def in ipairs(w.defs) do
			o(1,'d %s',san(def.part))
			checksyn{w=lit,dn=i}
			for j,r in ipairs(def.branch) do
				o(2,'dr %s',san(r))
			end
			for j,m in ipairs(def.means) do
				o(2,'m %s', san(m.lit))
				checksyn{w=lit,dn=i,mn=j}
				for k,n in ipairs(m.notes) do
					o(3,'n %s', san(n.kind))
					for a,p in ipairs(n.paras) do
						o(4,'np %s', san(p))
					end
				end
			end

		end
	end
	for _,s in ipairs(d.relsets) do o(0,'s %s %u', s.kind, s.uid) end
end

local function filterD(lst, fn)
-- cheap algorithm to destructively filter a list
................................................................................
			top = top - 1
		end
	end
	return lst
end

function cmds.mod.exec(ctx, orig, oper, dest, ...)
	if (not orig) or not oper then
		id10t '`mod` requires at least an origin and an operation'
	end
	local op, dp = pathParse(orig)
	local w,d,m,n = safeNavWord(ctx, op.w,op.dn,op.mn,op.nn)
	-- unfortunately, "pointers" exist elsewhere in the
	-- structure, currently just from relsets, that must
	-- be updated whenever an object moves or changes.
	-- this is miserable and takes a lot of work, using
	-- algorithms provided by the following functions.
	-- note that we don't bother trying to update the
	-- relcache as we go, it's simply not worth the work;
	-- instead we simply rebuild the whole cache when
	-- this command returns
	local function cleanupRels(path, fn)
		local rc = ctx.dict._relCache[path.w]
		if rc then
			for k,s in pairs(rc) do fn(s,k) end
		end
	end
	local function cleanupRelsEach(path, fn)
		cleanupRels(path, function(s,k)
			local top = #s.members
			for i=1,top do local m=s.members[i]
				if pathSub(path, m) then
					local val = fn(m,s,i)
					if val ~= nil then
						s.members[i] = val
					end
				end
			end
		end)
	end
	local function deleteRefsTo(path)
		cleanupRels(path, function(s)
		-- antonyms: delete the headword and transform the group
		-- to a list of synonyms
			if s.kind == 'ant' and pathSub(path,s.members[1]) then
				s.kind = 'syn'
			end
			filterD(s.members, function(m)
				return not pathSub(path, m)
			end)
		end)
		if not path.dn then
			ctx.dict._relCache[path.w] = nil
		end
	end
	local function moveRelTree(op,dp)
		cleanupRelsEach(op, function(old,set,idx)
			local new = {}
			for _,elt in pairs{'w','dn','mn','nn'} do
				if dp[elt] ~= nil then
					new[elt] = dp[elt]
				else
					new[elt] = op[elt] or old[elt]
				end
			end
			return new
		end)
	end
	local function shiftRelTree(dp, fld, nid, amt)
		local cleanupTargetMask = ({
			dn = {w=dp.w};
			mn = {w=dp.w,dn=dp.dn};
			nn = {w=dp.w,dn=dp.dn,mn=dp.mn};
		})[fld] -- >____<
		cleanupRelsEach(cleanupTargetMask, function(old,set,i)
			if old[fld] >= nid then
				old[fld] = old[fld] + amt
			end
		end)
	end
	local function insertAndMoveRelTree(tbl,n,op,dp,fld)
		local nid = #tbl
		local path = copy(dp)
		path[fld] = nid
		tbl[nid] = n
		shiftRelTree(dp,fld,1)
		moveRelTree(op, path)
	end
	if oper == 'drop' then
		-- clean out the cache and delete relationships
		deleteRefsTo(op)
		if not d then
			ctx.dict.words[op.w] = nil
		elseif not m then
			table.remove(w.defs, op.dn)
		elseif not n then
			table.remove(d.means, op.mn)
		else
			table.remove(m.notes, op.nn)
		end
	elseif oper == 'out' then
		if n or not m then id10t '`mod out` must target a meaning' end
		if not dest then id10t '`mod out` requires at least a part of speech' end
		local newdef = {
			part = dest;
			branch = {...};
			forms = {};
			means = {m};
		}
		shiftRelTree(op, 'dn', op.dn, 1)
		table.insert(w.defs,op.dn+1, newdef)
		moveRelTree(op,{w=op.w, dn=op.dn+1, mn=1})
		table.remove(d.means,op.mn)
	elseif oper == 'move' or oper == 'merge' or oper == 'clobber' then
		if dest
			then dp = pathParse(dest)
			else id10t('`mod %s` requires a target',oper)
		end
		if n then
			if not dp.mn then
				id10t '`mod` on a note requires a note or meaning destination'
			end
			local _,_,dm = safeNavWord(ctx, dp.w,dp.dn,dp.mn)
			if dp.nn then
				if oper == 'move' then
					shiftRelTree(dp, 'nn', dp.nn, 1)
					table.insert(dm.notes, dp.nn, n)
				elseif oper == 'merge' then
					local top = #(dm.notes[dp.nn].paras)
					for i, v in ipairs(n.paras) do
						dm.notes[dp.nn].paras[i+top] = v
					end
				elseif oper == 'clobber' then
					deleteRefsTo(dp)
					dm.notes[dp.nn] = n
				end
				moveRelTree(op,dp)
			else
				if oper ~= 'move' then
					id10t('`mod note %s` requires a note target', oper)
				end
				insertAndMoveRelTree(dm.notes,n,op,dp,'nn')
			end
			if oper == 'move' and dp.nn and dm == m and op.nn > dp.nn then
				table.remove(m.notes,op.nn+1)
			else
				table.remove(m.notes,op.nn)
			end
		elseif m then
			if not dp.dn then
				local newdef = {
					part = d.part;
					branch = copy(d.branch);
					forms = copy(d.forms);
					means = {m};
				}
				local didx
				if ctx.dict.words[dp.w] then
					local defst = ctx.dict.words[dp.w].defs
					didx = #defst
					defst[didx] = newdef
				else
					ctx.dict.words[dp.w] = {
						defs = {newdef};
					}
					didx = 1
				end
				cleanupRelsEach(op, function(oldpath,set,mi)
					return {w=dp.w,dn=didx,mn=1,nn=oldpath.nn}
				end)
				table.remove(d.means,dp.mn)
			else
				local dw, dd = safeNavWord(ctx, dp.w, dp.dn)
				if dp.mn then
					if dd.means[dp.mn] and (oper == 'merge' or oper=='clobber') then
						if oper == 'merge' then
							dd.means[dp.mn] = dd.means[dp.mn] .. '; ' .. m
						elseif oper == 'clobber' then
							deleteRefsTo(dp)
							dd.means[dp.mn] = m
						end
					else
						cleanupRelsEach({w=dp.w,dn=dp.dn}, function(old,set,i)
							if old.mn >= dp.mn then
								old.mn = old.mn + 1
							end
						end)
						table.insert(dd.means, dp.mn, m)
					end
					moveRelTree(op,dp)
				else
					insertAndMoveRelTree(dd.means,m, op,dp,'mn')
-- 					table.insert(dd.means, m)
				end
				if oper == 'move' and dp.mn and dd.means == d.means and op.mn > dp.mn then
					table.remove(d.means,op.mn+1)
				else
					table.remove(d.means,op.mn)
				end
			end
		elseif d then
			local ddefs = safeNavWord(ctx, dp.w).defs
			if dp.dn then
				if oper == 'merge' then
					local top = #(ddefs[dp.dn].means)
					for i,om in ipairs(d.means) do
						ddefs[dp.dn].means[top+i] = om
					end
					for k,p in pairs(d.forms) do
						deleteRefsTo(dp)
						ddefs[dp.dn].forms[k] = p -- clobbers!
					end
				else
					shiftRelTree(dp,'dn',dp.dn,1)
					table.insert(ddefs, dp.dn, d)
				end
				moveRelTree(op,dp)
			else
				insertAndMoveRelTree(ddefs,d, op,dp,'dn')
-- 				table.insert(ddefs, d)
			end
			if oper == 'move' and dp.mn and w.defs == ddefs and op.mn > dp.mn then
				table.remove(w.defs,op.dn+1)
			else
				table.remove(w.defs,op.dn)
			end
		else
			if ctx.dict.words[dp.w] then
				if oper ~= 'merge' then
					id10t('the word “%s” already exists; use `merge` if you want to merge the words together', dp.w)
				end
				for i,def in ipairs(w.defs) do
					local odp = copy(op) odp.dn = i
					local ddp = {w=dp.w, dn=dp.dn+i-1}
					if dp.dn then
						shiftRelTree(dp, 'dn', dp.dn+i-1, 1)
						table.insert(ctx.dict.words[dp.w].defs, dp.dn+i-1, def)
						moveRelTree(odp,ddp)
					else
-- 						table.insert(ctx.dict.words[dp.w].defs, def)
						insertAndMoveRelTree(ctx.dict.words[dp.w].defs, def,
													odp,dp,'dn')
					end
				end
			else
				ctx.dict.words[dp.w] = w
				moveRelTree(op,dp)
-- 				ctx.dict._relCache[dp.w] = ctx.dict._relCache[op.w]
-- 				ctx.dict._relCache[op.w] = nil
			end
			ctx.dict.words[op.w] = nil
		end
	end
	rebuildRelationCache(ctx.dict)
end

local function fileLegible(file)
	-- check if we can access the file
	local fd = io.open(file,"rb")
	local ret = false

		if src == nil then return end
		local sc = #src
		for j=1,sc do dest[i+j] = src[j] end
		i = i + sc
		iter(...)
	end
	iter(...)
end
local function fastDelete(table,idx)
-- delete without preserving table order
	local l = #table
	table[idx] = table[l]
	table[l] = nil
	return table
end
local function tcat(...)
	local new = {}
	tcatD(new, ...)
	return new
end
local ansi = {
................................................................................
		decode = function(s)
			local n = parse(ty,s)
			if (n+1) > #vals then error(string.format('enum "%s" does not have %u members', table.concat(vals,'","'),n),3) end
			return vals[n+1]
		end;
	}
end

fmt.uid = fmt.u32

fmt.relatable = function(ty)
	return tcat(ty,{
		{'rels',fmt.list(fmt.uid,fmt.u16)};
	})
end

fmt.note = {
	{'kind', fmt.tag};
	{'paras', fmt.list(fmt.string)};
}

fmt.example = {
	{'quote',fmt.string};
	{'src',fmt.label};
}

fmt.meaning = fmt.relatable {
	{'lit', fmt.string};
	{'examples', fmt.list(fmt.example,fmt.u8)};
	{'notes', fmt.list(fmt.note,fmt.u8)};
}

fmt.phrase = fmt.relatable {
	{'str',fmt.label};
	{'means',fmt.list(fmt.meaning,fmt.u8)};

}

fmt.def = fmt.relatable {
	{'part', fmt.u8};
	{'branch', fmt.list(fmt.label,fmt.u8)};
	{'means', fmt.list(fmt.meaning,fmt.u8)};
	{'forms', fmt.map(fmt.u16,fmt.label,fmt.u16)};
	{'phrases', fmt.list(fmt.phrase,fmt.u16)};
}

fmt.word = fmt.relatable {
	{'defs', fmt.list(fmt.def,fmt.u8)};
}

fmt.dictHeader = {
	{'lang', fmt.tag};
	{'meta', fmt.string};
	{'partsOfSpeech', fmt.list(fmt.tag,fmt.u16)};
................................................................................
		{'parts', fmt.list(fmt.tag,fmt.u8)};
		-- which parts of speech does this form apply to?
		-- leave empty if not relevant
	},fmt.u16)};
}

fmt.relSet = {
	{'uid', fmt.uid};
		-- IDs are persistent random values so they can be used
		-- as reliable identifiers even when merging exports in
		-- a parvan-unaware VCS

	{'kind', fmt.enum('syn','ant','met')};
	-- membership is stored in individual objects, using a field
	-- attached by the 'relatable' template
}

fmt.dict = {
	{'header', fmt.dictHeader};
	{'words', fmt.map(fmt.string,fmt.word)};
	{'relsets', fmt.list(fmt.relSet)};
}
................................................................................
end

local function rebuildRelationCache(d)
-- (re)build a dictionary's relation cache; needed
-- at load time and whenever any changes to relsets
-- are made (unless they're simple enough to update
-- the cache directly by hand, but that's very eeeh)
	local setMems = {} -- indexed by set id
	local function scan(obj,path)
		for _,v in pairs(obj.rels) do
			setMems[v] = setMems[v] or {mems={}}
			table.insert(setMems[v].mems, {path=path, obj=obj})
		end
	end
	for wk,wv in pairs(d.words) do
		scan(wv, {w=wk})
		for dk,dv in pairs(wv.defs) do
			scan(dv, {w=wk, dn=dk})
			for mk,mv in pairs(dv.means) do
				scan(mv, {w=wk, dn=dk, mn=mk})
			end
			for pk,pv in pairs(dv.phrases) do
				scan(pv, {w=wk, dn=dk, pn=pk})
				for mk,mv in pairs(pv.means) do
					scan(mv, {w=wk, dn=dk, pn=pk, mn=mk})
				end
			end
		end
	end
	for sk,sv in pairs(d.relsets) do
		setMems[sv.uid] = setMems[sv.uid] or {}
		setMems[sv.uid].set = sv
	end
	d._relCache = setMems
end

local function
writeDict(d)
	local atomizePoS, posMap = atomizer()
	for lit,w in pairs(d.words) do
		for j,def in ipairs(w.defs) do
................................................................................
		if not fd then error(userError("cannot open file " .. file),2) end
		return fd
	else
		return file
	end
end




















local function copy(tab)
	local new = {}
	for k,v in pairs(tab) do new[k] = v end
	return new
end

local function pathParse(p)
................................................................................
		and a.dn == b.dn
		and a.mn == b.mn
		and a.pn == b.pn
		and a.nn == b.nn
		and a.xn == b.xn
end
local function pathResolve(ctx, a)
	local res = {}

	if not a.w then return res end -- empty paths are valid!
	local function lookup(seg, tbl,val)
		if not tbl then error('bad table',2) end
		local v = tbl[val]
		if v then return v end
		id10t('bad %s in path: %s', seg, val)
	end


	res.word = lookup('word', ctx.dict.words, a.w)
	if not a.dn then return res end

	res.def = lookup('definition', res.word.defs, a.dn)
	if (not a.pn) and (not a.mn) then return res end

	local m if a.pn then
		res.phrase = lookup('phrase', res.def.phrases, a.pn)
		res.meaning = lookup('meaning', res.phrase.means, a.mn)
	else
		res.meaning = lookup('meaning', res.def.means, a.mn)
	end

	if a.xn then
		res.ex = lookup('example',res.meaning.examples,a.xn)
	elseif a.nn then
		res.note = lookup('note',res.meaning.notes,a.nn)
	end

	return res
end

local function pathNav(...)
	local t = pathResolve(...)
................................................................................
		help = "add a new word";
		syntax = "<word>";
		write = true;
		exec = function(ctx,word)
			if ctx.dict.words[word] then
				id10t "word already coined"
			end
			ctx.dict.words[word] = {defs={},rels={}}
		end;
	};
	def = {
		help = "define a word";
		syntax = "<word> <part-of-speech> [<meaning> [<root>…]]";
		write = true;
		exec = function(ctx,word,part,means,...)
			local etym = {...}
			if (not word) or not part then
				id10t 'bad definition'
			end
			if not ctx.dict.words[word] then
				ctx.dict.words[word] = {defs={},rels={}}
			end
			local n = #(ctx.dict.words[word].defs)+1
			ctx.dict.words[word].defs[n] = {
				part = part;
				branch = etym;
				means = {means and {
					lit=means;
					examples={};
					notes={};
					rels={};
				} or nil};
				forms = {};
				phrases = {};
				rels={};
			}
			ctx.log('info', string.format('added definition #%u to “%s”', n, word))
		end;
	};
	mean = {
		help = "add a meaning to a definition";
		syntax = "<word> <def#> <meaning>";
................................................................................
				end
				local links={}
				for i,l in ipairs{select(2,...)} do
					links[i] = pathParse(l)
				end
				local newstruct = {
					uid=math.random(1,0xffffFFFF);

					kind = rel;
				}
				table.insert(ctx.dict.relsets, newstruct)
				for _, m in pairs(links) do
					local obj = pathRef(ctx,m)
					table.insert(obj.rels,newstruct.uid)
				end


				rebuildRelationCache(ctx.dict)
			else -- assemble a list of groups
				local tgtw = ...
				local wp = pathParse(tgtw)
				local o = pathResolve(ctx, wp)

				for i,rs in pairs(ctx.dict.relsets) do
					local allMembers = ctx.dict._relCache[rs.uid].mems
					for j,s in ipairs(allMembers) do
						if pathSub(s.path, wp) then

							table.insert(groups, {
								set = {
									uid = rs.uid;
									kind = rs.kind;
									members = allMembers;
								};
								mem = s;
								id = i;
							})
							break
						end
					end
				end

				if op == 'show' then
					for i, g in ipairs(groups) do
................................................................................
								end
							end

							return repr
						end

						local others = {}
						for j, oo in ipairs(g.set.members) do
							local o = oo.path
							local ow = pathResolve(ctx, {w=o.w}).w
							if (g.set.kind == 'ant' or not pathMatch(o, g.mem.path)) and
								--exclude antonym headwords
								not (g.set.kind == 'ant' and j==1) then
								table.insert(others, '      '..label(o,ow))
							end
						end
						local llab do
							local cdw = ctx.dict.words
							if g.set.kind == 'ant' then
								local ap = g.set.members[1].path
								llab = fo.br(label(ap,cdw[ap.w]) or '')
							else
								llab = fo.br(label(g.mem.path,cdw[g.mem.w]) or '')
							end
						end
						local kls = {
							syn = fo.color('synonyms',2,true)..' of';
							ant = fo.color('antonyms',1,true)..' of';
							met = fo.color('metonyms',4,true)..' of';
						}
................................................................................
					local tgtn, paths = (select(2,...)), { select(3, ...) }
					rebuildRelationCache(ctx.dict)
				elseif op == 'destroy' then
					local tgtw, tgtn = ...
					if not tgtn then id10t 'missing group number' end
					local delendum = groups[tonumber(tgtn)]
					if not delendum then id10t 'bad group number' end

					for k,v in pairs(delendum.set.members) do
						for idx, e in pairs(v.obj.rels) do
							if e == delendum.set.uid then
								fastDelete(v.obj.rels,idx)
							end
						end
					end
					fastDelete(ctx.dict.relsets, delendum.id)

					rebuildRelationCache(ctx.dict)
				else
					id10t 'invalid operation'
				end
			end
		end;
	};
................................................................................
		help = "add a note to a definition or a paragraph to a note";
		syntax = {"(<m-path> (add|for) <kind> | <m-path>:<note#>) <para>…";
			"m-path ::= <word>@<def#>/<meaning#>"};
		write = true;
		exec = function(ctx,path,...)
			local paras, mng
			local dest = pathParse(path)
			local t = pathResolve(ctx,path)
			if dest.nn then
				paras = {...}
			else
				local op, kind = ...
				paras = { select(3, ...) }
				if op == 'add' then
					dest.nn = #(t.m.notes) + 1
					t.m.notes[dest.nn] = {kind=kind, paras=paras}
					return
				elseif op == 'for' then
					for i,nn in ipairs(t.m.notes) do
						if nn.kind == kind then
							dest.nn = i break
						end
					end
					if not dest.nn then
						id10t('no note of kind %s in %s',kind,path)
					end
				end
			end
			local dpa = t.m.notes[dest.nn].paras
			local top = #dpa
			for i,p in ipairs(paras) do
				dpa[top+i] = p
			end
		end
	};
	shell = {
................................................................................
		end
	end
	table.sort(out, function(a,b) return a.lit < b.lit end)
	local fo = ctx.sty[io.stdout]

	local function gatherRelSets(path)
		local antonymSets, synonymSets, metonymSets = {},{},{}
		local obj = pathRef(ctx,path)
		if next(obj.rels) then
			for i, relid in ipairs(obj.rels) do
				local specuset,tgt,anto = {}
				local rel = ctx.dict._relCache[relid].set
				for j, mbr in ipairs(ctx.dict._relCache[relid].mems) do
					if pathMatch(mbr.path, path) then
						if     rel.kind == 'syn' then tgt = synonymSets
						elseif rel.kind == 'met' then tgt = metonymSets
						elseif rel.kind == 'ant' then
							if j == 1 -- is this the headword?
								then tgt = antonymSets
								else tgt = synonymSets
							end
						end
					elseif j == 1 and rel.kind == 'ant' then
						anto = mbr.path
					else
						table.insert(specuset, mbr.path)
					end
				end
				if tgt then
					table.insert(tgt, specuset)
					if anto then
						table.insert(antonymSets, {anto})
					end
................................................................................
	end
	for i, w in ipairs(out) do
		local d = fo.ul(fo.br(w.lit))
		local wordrels = autobreak(table.concat(
				formatRels(gatherRelSets{w=w.lit}, 2),
				'\n'
			))

		if #w.word.defs == 1 then
			d=d .. ' '
			    .. fo.rgb(fo.em('('..(w.word.defs[1].part)..')'),.8,.5,1) .. '\n'
			    .. meanings(w,w.word.defs[1],false,1) .. '\n'
			    .. autobreak(table.concat(formatRels(gatherRelSets{w=w.lit,dn=1}, 4), '\n'))
				 .. wordrels .. '\n'
		else
................................................................................
				if c ~= 'pv0' then
					id10t "not a parvan export"
				end
				new.header.lang = words[2]
				new.header.meta = words[3]
				state = 1
			else

				local T = pathResolve({dict=new}, path)
				local W,D,P,M,N,X =
					T.word,
					T.def,
					T.phrase,
					T.meaning,
					T.note,
					T.ex
				if c == 'w' then syn(1) state = 2
					path = {w=words[2]}
					new.words[words[2]] = {defs={},rels={}}
				elseif c == 'f' then syn(1)
					local nf = {
						name = words[2];
						abbrev = words[3] or "";
						desc = words[4] or "";
						parts = {};
					}
................................................................................
					table.insert(lastinfl.parts,words[2])
				elseif c == 's' then syn(2)
					relsets[words[3]] = relsets[words[3]] or {}
					relsets[words[3]].kind = words[2]
					relsets[words[3]].uid = tonumber(words[3])
					relsets[words[3]].members = relsets[words[3]].members or {}
				elseif state >= 2 and c == 'r' then syn(1)
					local rt
					if state == 2 then
						rt = W.rels
					elseif state == 3 then
						rt = D.rels
					elseif state == 4 then
						rt = D.rels
					elseif state == 14 then
						rt = P.rels
					end
					relsets[words[2]] = relsets[words[2]] or {
						uid = tonumber(words[2]) or math.random(0,0xffffFFFF);
						members={};
					}
					table.insert(relsets[words[2]].members, path)
				elseif state >= 2 and c == 'd' then syn(1) state = 3
					table.insert(W.defs, {
						part = words[2];
						branch = {};
						means = {};
						forms = {};
						phrases = {};
						rels = {};
					})
					path = {w = path.w, dn = #(W.defs)}
				elseif state >= 3 and c == 'dr' then syn(1)
					table.insert(D.branch, words[2])
				elseif state >= 3 and c == 'df' then syn(2)
					if not inflmap[words[2]] then
						id10t('no inflection form %s defined', words[2])
					end
					D.forms[inflmap[words[2]]] = words[3]
				elseif state >= 3 and c == 'p' then syn(1) state = 14
					table.insert(D.phrases, {
						str = words[2];
						means = {};
						rels = {};
					})
					path = {w = path.w, dn = path.dn, pn = #(D.phrases)}
				elseif state >= 3 and c == 'm' then syn(1) state = 4
					table.insert(D.means, {
						lit = words[2];
						notes = {};
						examples = {};
						rels = {};
					});
					path = {w = path.w, dn = path.dn, pn=path.pn, mn = #(D.means)}
				elseif state >= 4 and c == 'n' then syn(1) state = 5
					table.insert(M.notes, {kind=words[2], paras={}})
					path = {w = path.w, dn = path.dn, pn = path.pn, mn = path.mn, nn = #(M.notes)};
				elseif state >= 5 and c == 'np' then syn(1)
					table.insert(N.paras, words[2])
				end
				-- we ignore invalid ctls, for sake of forward-compat
			end
		end
	end
................................................................................

	for k,v in pairs(relsets) do
		if not v.uid then
			--handle non-numeric export ids
			v.uid = math.random(0,0xffffFFFF)
		end
		table.insert(new.relsets, v)

		for q,m in pairs(v.members) do
			table.insert(pathRef({dict=new},m).rels, v.uid)
		end
	end

	local ofd = safeopen(ctx.file,"w+b")
	local o = writeDict(new);
	ofd:write(o)
	ofd:close()
end
................................................................................
		if ctx.flags.human and lvl > 0 then
			pfx = string.rep('\t', lvl)
		end
		ofd:write(pfx..string.format(...)..'\n')
	end
	local d = ctx.dict
	o(0,'pv0 %s %s', san(d.header.lang), san(d.header.meta))
	local function checksyn(obj,lvl)
		for k,v in pairs(obj.rels) do









			o(lvl,'r %u',s.uid)



		end
	end
	for i,f in pairs(d.header.inflectionForms) do
		o(0,'f %s %s %s', san(f.name), san(f.abbrev), san(f.desc))
		for j,p in pairs(f.parts) do
			o(1,'fp %s', san(p))
		end
	end
	local function scanMeans(tbl,path,lvl)
		for j,m in ipairs(def.means) do
			o(lvl,'m %s', san(m.lit))
			local lp = copy(path)
			lp.mn = j
			checksyn(m,lp,lvl+1)
			for k,n in ipairs(m.notes) do
				o(lvl+1,'n %s', san(n.kind))
				for a,p in ipairs(n.paras) do
					o(lvl+2,'np %s', san(p))
				end
			end
		end
	end
	for lit, w in pairs(d.words) do
		o(0,'w %s',san(lit))
		checksyn(w,{w=lit},1)
		for i,def in ipairs(w.defs) do
			o(1,'d %s',san(def.part))
			checksyn(def,{w=lit,dn=i},2)
			for j,r in ipairs(def.branch) do
				o(2,'dr %s',san(r))
			end
			for j,p in ipairs(def.phrases) do
				o(2,'p %s',san(p.str))
				scanMeans(p.means, {w=lit,dn=i,pn=j}, 3)




			end


			scanMeans(def.means, {w=lit,dn=i}, 2)
		end
	end
	for _,s in ipairs(d.relsets) do o(0,'s %s %u', s.kind, s.uid) end
end

local function filterD(lst, fn)
-- cheap algorithm to destructively filter a list
................................................................................
			top = top - 1
		end
	end
	return lst
end

function cmds.mod.exec(ctx, orig, oper, dest, ...)






















































































































































































































































	rebuildRelationCache(ctx.dict)
end

local function fileLegible(file)
	-- check if we can access the file
	local fd = io.open(file,"rb")
	local ret = false