stable 2008.05.09 19:33

1 files changed, 347 insertions, 82 deletions

diff --git a/tex/context/base/l-xml.lua b/tex/context/base/l-xml.lua
index 06f527cad..752ff3f74 100644
--- a/tex/context/base/l-xml.lua
+++ b/tex/context/base/l-xml.lua
@@ -8,6 +8,8 @@ if not modules then modules = { } end modules ['l-xml'] = {
 
 -- RJ: key=value ... lpeg.Ca(lpeg.Cc({}) * (pattern-producing-key-and-value / rawset)^0)
 
+-- some code may move to l-xmlext
+
 --[[ldx--
 <p>The parser used here is inspired by the variant discussed in the lua book, but
 handles comment and processing instructions, has a different structure, provides
@@ -154,7 +156,7 @@ do
 
     local remove, nsremap, resolvens = table.remove, xml.xmlns, xml.resolvens
 
-    local stack, top, dt, at, xmlns, errorstr = {}, {}, {}, {}, {}, nil
+    local stack, top, dt, at, xmlns, errorstr, entities = {}, {}, {}, {}, {}, nil, {}
 
     local mt = { __tostring = xml.text }
 
@@ -214,9 +216,10 @@ do
         end
         local resolved = (namespace == "" and xmlns[#xmlns]) or nsremap[namespace] or namespace
         top = stack[#stack]
-        setmetatable(top, mt)
         dt = top.dt
-        dt[#dt+1] = { ns=namespace or "", rn=resolved, tg=tag, at=at, dt={}, __p__ = top }
+        local t = { ns=namespace or "", rn=resolved, tg=tag, at=at, dt={}, __p__ = top }
+        dt[#dt+1] = t
+        setmetatable(t, mt)
         at = { }
         if at.xmlns then
             remove(xmlns)
@@ -229,14 +232,6 @@ do
             dt[#dt+1] = text
         end
     end
-    --~ local function add_special(what, spacing, text)
-    --~     if #spacing > 0 then
-    --~         dt[#dt+1] = spacing
-    --~     end
-    --~     top = stack[#stack]    -- hm, left over 1
-    --~     setmetatable(top, mt)  -- hm, left over 2
-    --~     dt[#dt+1] = { special=true, ns="", tg=what, dt={text} }
-    --~ end
     local function add_special(what, spacing, text)
         if #spacing > 0 then
             dt[#dt+1] = spacing
@@ -296,12 +291,20 @@ do
     local somecomment      = C((1 - endcomment    )^0)
     local somecdata        = C((1 - endcdata      )^0)
 
+    function entity(k,v) entities[k] = v end
+
     local begindoctype     = open * P("!DOCTYPE")
     local enddoctype       = close
-    local publicdoctype    = P("PUBLIC") * somespace * value * somespace * value * somespace * balanced^0
-    local systemdoctype    = P("SYSTEM") * somespace * value * somespace                     * balanced^0
-    local simpledoctype    = (1-close)^1                                                          * balanced^0
-    local somedoctype      = C((somespace * P(publicdoctype + systemdoctype + simpledoctype) * optionalspace)^0)
+    local beginset         = P("[")
+    local endset           = P("]")
+    local doctypename      = C((1-somespace)^0)
+    local elementdoctype   = optionalspace * P("<!ELEMENT") * (1-close)^0 * close
+    local entitydoctype    = optionalspace * P("<!ENTITY") * somespace * (doctypename * somespace * value)/entity * optionalspace * close
+    local publicdoctype    = doctypename * somespace * P("PUBLIC") * somespace * value * somespace * value * somespace
+    local systemdoctype    = doctypename * somespace * P("SYSTEM") * somespace * value * somespace
+    local definitiondoctype= doctypename * somespace * beginset * P(elementdoctype + entitydoctype)^0 * optionalspace * endset
+    local simpledoctype    = (1-close)^1                     -- * balanced^0
+    local somedoctype      = C((somespace * (publicdoctype + systemdoctype + definitiondoctype + simpledoctype) * optionalspace)^0)
 
     local instruction      = (spacing * begininstruction * someinstruction * endinstruction) / function(...) add_special("@pi@",...) end
     local comment          = (spacing * begincomment     * somecomment     * endcomment    ) / function(...) add_special("@cm@",...) end
@@ -327,9 +330,11 @@ do
         children = text + V("parent") + emptyelement + comment + cdata + instruction,
     }
 
-    function xml.convert(data, no_root, strip_cm_and_dt)
+    -- todo: xml.new + properties like entities and strip and such (store in root)
+
+    function xml.convert(data, no_root, strip_cm_and_dt, given_entities) -- maybe use table met k/v (given_entities may disapear)
         strip = strip_cm_and_dt or xml.strip_cm_and_dt
-        stack, top, at, xmlns, errorstr, result = {}, {}, {}, {}, nil, nil
+        stack, top, at, xmlns, errorstr, result, entities = {}, {}, {}, {}, nil, nil, given_entities or {}
         stack[#stack+1] = top
         top.dt = { }
         dt = top.dt
@@ -348,7 +353,7 @@ do
             result = stack[1]
         end
         if not no_root then
-            result = { special = true, ns = "", tg = '@rt@', dt = result.dt, at={} }
+            result = { special = true, ns = "", tg = '@rt@', dt = result.dt, at={}, entities = entities }
             setmetatable(result, mt)
             local rdt = result.dt
             for k=1,#rdt do
@@ -382,7 +387,7 @@ do
         return root and not root.error
     end
 
-    xml.error_handler = (logs and logs.report) or print
+    xml.error_handler = (logs and logs.report) or (input and input.report) or print
 
 end
 
@@ -560,7 +565,7 @@ do
                             handle("<" .. ens .. ":" .. etg .. " " .. concat(ats," ") .. "/>")
                         else
                         --  handle(format("<%s:%s/>",ens,etg))
-                            handle("<" .. ens .. ":" .. "/>")
+                            handle("<" .. ens .. ":" .. etg .. "/>")
                         end
                     end
                 else
@@ -742,6 +747,10 @@ will explain more about its usage in other documents.</p>
 
 do
 
+    xml.functions = xml.functions or { }
+
+    local functions = xml.functions
+
     local actions = {
         [10] = "stay",
         [11] = "parent",
@@ -764,19 +773,72 @@ do
         [40] = "processing instruction",
     }
 
-    local function make_expression(str) --could also be an lpeg
-        str = str:gsub("@([a-zA-Z%-_]+)", "(a['%1'] or '')")
-        str = str:gsub("position%(%)", "i")
-        str = str:gsub("text%(%)", "t")
-        str = str:gsub("!=", "~=")
-        str = str:gsub("([^=!~<>])=([^=!~<>])", "%1==%2")
-        str = str:gsub("([a-zA-Z%-_]+)%(", "functions.%1(")
-        return str, loadstring(format("return function(functions,i,a,t) return %s end", str))()
+    --~     local function make_expression(str) --could also be an lpeg
+    --~         str = str:gsub("@([a-zA-Z%-_]+)", "(a['%1'] or '')")
+    --~         str = str:gsub("position%(%)", "i")
+    --~         str = str:gsub("text%(%)", "t")
+    --~         str = str:gsub("!=", "~=")
+    --~         str = str:gsub("([^=!~<>])=([^=!~<>])", "%1==%2")
+    --~         str = str:gsub("([a-zA-Z%-_]+)%(", "functions.%1(")
+    --~         return str, loadstring(format("return function(functions,i,a,t) return %s end", str))()
+    --~     end
+
+    -- a rather dumb lpeg
+
+    local P, S, R, C, V, Cc = lpeg.P, lpeg.S, lpeg.R, lpeg.C, lpeg.V, lpeg.Cc
+
+    local lp_position  = P("position()") / "id"
+    local lp_text      = P("text()")     / "tx"
+    local lp_name      = P("name()")     / "((rt.ns~='' and rt.ns..':'..rt.tg) or '')"
+    local lp_tag       = P("tag()")      / "(rt.tg or '')"
+    local lp_ns        = P("ns()")       / "(rt.ns or '')"
+    local lp_noequal   = P("!=")         / "~=" + P("<=") + P(">=") + P("==")
+    local lp_doequal   = P("=")          / "=="
+    local lp_attribute = P("@")          / "" * Cc("(at['") * R("az","AZ","--","__")^1 * Cc("'] or '')")
+
+    local lp_function  = C(R("az","AZ","--","__")^1) * P("(") / function(t)
+        if functions[t] then
+            return "functions." .. t .. "("
+        else
+            return "functions.error("
+        end
     end
 
-    local map = { }
+    local lparent  = lpeg.P("(")
+    local rparent  = lpeg.P(")")
+    local noparent = 1 - (lparent+rparent)
+    local nested   = lpeg.P{lparent * (noparent + lpeg.V(1))^0 * rparent}
+    local value    = lpeg.P(lparent * lpeg.C((noparent + nested)^0) * rparent)
 
-    local P, S, R, C, V = lpeg.P, lpeg.S, lpeg.R, lpeg.C, lpeg.V
+--~ local value = P { "(" * C(((1 - S("()")) + V(1))^0) * ")" }
+
+    local lp_special = (C(P("name")+P("text")+P("tag"))) * value / function(t,s)
+        if functions[t] then
+            if s then
+                return "functions." .. t .. "(rt,k," .. s ..")"
+            else
+                return "functions." .. t .. "(rt,k)"
+            end
+        else
+            return "functions.error(" .. t .. ")"
+        end
+    end
+
+    local converter = lpeg.Cs ( (
+        lp_position +
+        lp_text + lp_name + -- fast one
+        lp_special +
+        lp_noequal + lp_doequal +
+        lp_attribute +
+        lp_function +
+    1 )^1 )
+
+    local function make_expression(str)
+        str = converter:match(str)
+        return str, loadstring(format("return function(functions,id,at,tx,rt,k) return %s end", str))()
+    end
+
+    local map = { }
 
     local space             = S(' \r\n\t')
     local squote            = S("'")
@@ -796,8 +858,10 @@ do
     local bar               = P('|')
     local hat               = P('^')
     local valid             = R('az', 'AZ', '09') + S('_-')
-    local name_yes          = C(valid^1) * colon * C(valid^1 + star) -- permits ns:*
-    local name_nop          = C(P(true)) * C(valid^1)
+--~     local name_yes          = C(valid^1 + star) * colon * C(valid^1 + star) -- permits ns:* *:tg *:*
+--~     local name_nop          = C(P(true)) * C(valid^1)
+    local name_yes          = C(valid^1 + star) * colon * C(valid^1 + star) -- permits ns:* *:tg *:*
+    local name_nop          = Cc("*") * C(valid^1)
     local name              = name_yes + name_nop
     local number            = C((S('+-')^0 * R('09')^1)) / tonumber
     local names             = (bar^0 * name)^1
@@ -859,8 +923,10 @@ do
     local expression               = (is_one  * is_expression)/ function(...) map[#map+1] = { 31, true,  ... } end
     local dont_expression          = (is_none * is_expression)/ function(...) map[#map+1] = { 31, false, ... } end
 
-    local self_expression          = (         is_expression)/ function(...) map[#map+1] = { 31, true,  "", "*", ... } end
-    local dont_self_expression     = (exclam * is_expression)/ function(...) map[#map+1] = { 31, true,  "", "*", ... } end
+    local self_expression          = (         is_expression) / function(...) if #map == 0 then map[#map+1] = { 11 } end
+                                                                              map[#map+1] = { 31, true,  "*", "*", ... } end
+    local dont_self_expression     = (exclam * is_expression) / function(...) if #map == 0 then map[#map+1] = { 11 } end
+                                                                              map[#map+1] = { 31, false, "*", "*", ... } end
 
     local instruction              = (instructiontag * text ) / function(...) map[#map+1] = { 40,        ... } end
     local nothing                  = (empty                 ) / function(   ) map[#map+1] = { 15             } end -- 15 ?
@@ -988,8 +1054,10 @@ do
     function xml.xshow(e,...) -- also handy when report is given, use () to isolate first e
         local t = { ... }
         local report = (type(t[#t]) == "function" and t[#t]) or fallbackreport
-        if not e then
+        if e == nil then
             report("<!-- no element -->\n")
+        elseif type(e) ~= "table" then
+            report(tostring(e))
         elseif e.tg then
             report(tostring(e) .. "\n")
         else
@@ -1016,8 +1084,6 @@ advance what we want to do with the found element the handle gets three argument
 functions.</p>
 --ldx]]--
 
-xml.functions = { }
-
 do
 
     local functions = xml.functions
@@ -1028,11 +1094,85 @@ do
     functions.lower    = string.lower
     functions.number   = tonumber
     functions.boolean  = toboolean
-    functions.oneof    = function(s,...) -- slow
+
+    functions.oneof = function(s,...) -- slow
         local t = {...} for i=1,#t do if s == t[i] then return true end end return false
     end
+    functions.error = function(str)
+        xml.error_handler("unknown function in lpath expression",str)
+        return false
+    end
+    functions.text = function(root,k,n) -- unchecked, maybe one deeper
+        local t = type(t)
+        if t == "string" then
+            return t
+        else -- todo n
+            local rdt = root.dt
+            return (rdt and rdt[k]) or root[k] or ""
+        end
+    end
+    functions.name = function(root,k,n)
+        -- way too fuzzy
+        local found
+        if not k or not n then
+            local ns, tg = root.ns, root.tg
+            if not tg then
+                for i=1,#root do
+                    local e = root[i]
+                    if type(e) == "table" then
+                        found = e
+                        break
+                    end
+                end
+            elseif ns == "" then
+                return tg
+            else
+                return ns .. ":" .. tg
+            end
+        elseif n == 0 then
+            local e = root[k]
+            if type(e) ~= "table" then
+                found = e
+            end
+        elseif n < 0 then
+            for i=k-1,1,-1 do
+                local e = root[i]
+                if type(e) == "table" then
+                    if n == -1 then
+                        found = e
+                        break
+                    else
+                        n = n + 1
+                    end
+                end
+            end
+        else
+--~ print(k,n,#root)
+            for i=k+1,#root,1 do
+                local e = root[i]
+                if type(e) == "table" then
+                    if n == 1 then
+                        found = e
+                        break
+                    else
+                        n = n - 1
+                    end
+                end
+            end
+        end
+        if found then
+            local ns, tg = found.ns, found.tg
+            if ns ~= "" then
+                return ns .. ":" .. tg
+            else
+                return tg
+            end
+        else
+            return ""
+        end
+    end
 
-    local function traverse(root,pattern,handle,reverse,index,parent,wildcard)
+    local function traverse(root,pattern,handle,reverse,index,parent,wildcard) -- multiple only for tags, not for namespaces
         if not root then -- error
             return false
         elseif pattern == false then -- root
@@ -1059,11 +1199,15 @@ do
                 local rootdt = root.dt
                 for k=1,#rootdt do
                     local e = rootdt[k]
-                    local ns, tg = (e.rn or e.ns), e.tg
-                    local matched = ns == action[3] and tg == action[4]
-                    if not action[2] then matched = not matched end
-                    if matched then
-                        if handle(root,rootdt,k) then return false end
+                    local tg = e.tg
+                    if e.tg then
+                        local ns = e.rn or e.ns
+                        local ns_a, tg_a = action[3], action[4]
+                        local matched = (ns_a == "*" or ns == ns_a) and (tg_a == "*" or tg == tg_a)
+                        if not action[2] then matched = not matched end
+                        if matched then
+                            if handle(root,rootdt,k) then return false end
+                        end
                     end
                 end
             elseif command == 11 then -- parent
@@ -1106,8 +1250,14 @@ do
                         if tg then
                             idx = idx + 1
                             if command == 30 then
-                                local tg_a = action[4]
-                                if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                local ns_a, tg_a = action[3], action[4]
+                                if tg == tg_a then
+                                    matched = ns_a == "*" or ns == ns_a
+                                elseif tg_a == '*' then
+                                    matched, multiple = ns_a == "*" or ns == ns_a, true
+                                else
+                                    matched = false
+                                end
                                 if not action[2] then matched = not matched end
                                 if matched then
                                     n = n + dn
@@ -1125,57 +1275,102 @@ do
                             else
                                 local matched, multiple = false, false
                                 if command == 20 then -- match
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                    local ns_a, tg_a = action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     if not action[2] then matched = not matched end
                                 elseif command == 21 then -- match one of
                                     multiple = true
                                     for i=3,#action,2 do
-                                        if ns == action[i] and tg == action[i+1] then matched = true break end
+                                        local ns_a, tg_a = action[i], action[i+1]
+                                        if (ns_a == "*" or ns == ns_a) and (tg == "*" or tg == tg_a) then
+                                            matched = true
+                                            break
+                                        end
                                     end
                                     if not action[2] then matched = not matched end
                                 elseif command == 22 then -- eq
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
-                                    if not action[2] then matched = not matched end
+                                    local ns_a, tg_a = action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     matched = matched and e.at[action[6]] == action[7]
                                 elseif command == 23 then -- ne
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                    local ns_a, tg_a = action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     if not action[2] then matched = not matched end
                                     matched = mached and e.at[action[6]] ~= action[7]
                                 elseif command == 24 then -- one of eq
                                     multiple = true
                                     for i=3,#action-2,2 do
-                                        if ns == action[i] and tg == action[i+1] then matched = true break end
+                                        local ns_a, tg_a = action[i], action[i+1]
+                                        if (ns_a == "*" or ns == ns_a) and (tg == "*" or tg == tg_a) then
+                                            matched = true
+                                            break
+                                        end
                                     end
                                     if not action[2] then matched = not matched end
                                     matched = matched and e.at[action[#action-1]] == action[#action]
                                 elseif command == 25 then -- one of ne
                                     multiple = true
                                     for i=3,#action-2,2 do
-                                        if ns == action[i] and tg == action[i+1] then matched = true break end
+                                        local ns_a, tg_a = action[i], action[i+1]
+                                        if (ns_a == "*" or ns == ns_a) and (tg == "*" or tg == tg_a) then
+                                            matched = true
+                                            break
+                                        end
                                     end
                                     if not action[2] then matched = not matched end
                                     matched = matched and e.at[action[#action-1]] ~= action[#action]
                                 elseif command == 27 then -- has attribute
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                    local ns_a, tg_a = action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     if not action[2] then matched = not matched end
                                     matched = matched and e.at[action[5]]
                                 elseif command == 28 then -- has value
-                                    local edt = e.dt
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                    local edt, ns_a, tg_a = e.dt, action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     if not action[2] then matched = not matched end
                                     matched = matched and edt and edt[1] == action[5]
                                 elseif command == 31 then
-                                    local edt = e.dt
-                                    local tg_a = action[4]
-                                    if tg == tg_a then matched = ns == action[3] elseif tg_a == '*' then matched, multiple = ns == action[3], true else matched = false end
+                                    local edt, ns_a, tg_a = e.dt, action[3], action[4]
+                                    if tg == tg_a then
+                                        matched = ns_a == "*" or ns == ns_a
+                                    elseif tg_a == '*' then
+                                        matched, multiple = ns_a == "*" or ns == ns_a, true
+                                    else
+                                        matched = false
+                                    end
                                     if not action[2] then matched = not matched end
                                     if matched then
-                                        matched = action[6](functions,idx,e.at or { },edt[1])
+                                        matched = action[6](functions,idx,e.at or { },edt[1],rootdt,k)
                                     end
                                 end
                                 if matched then -- combine tg test and at test
@@ -1351,7 +1546,7 @@ do
     end
     function xml.filters.text(root,pattern,arguments) -- ?? why index, tostring slow
         local dtk, rt, dt, dk = xml.filters.index(root,pattern,arguments)
-        if dtk then
+        if dtk then -- n
             local dtkdt = dtk.dt
             if not dtkdt then
                 return "", rt, dt, dk
@@ -1364,6 +1559,22 @@ do
             return "", rt, dt, dk
         end
     end
+    function xml.filters.tag(root,pattern,n)
+        local tag = ""
+        traverse(root, lpath(pattern), function(r,d,k)
+            tag = xml.functions.tag(d,k,n and tonumber(n))
+            return true
+        end)
+        return tag
+    end
+    function xml.filters.name(root,pattern,n)
+        local tag = ""
+        traverse(root, lpath(pattern), function(r,d,k)
+            tag = xml.functions.name(d,k,n and tonumber(n))
+            return true
+        end)
+        return tag
+    end
 
     --[[ldx--
     <p>For splitting the filter function from the path specification, we can
@@ -1375,21 +1586,28 @@ do
 
     local P, S, R, C, V, Cc = lpeg.P, lpeg.S, lpeg.R, lpeg.C, lpeg.V, lpeg.Cc
 
-    local name      = (R("az","AZ")+R("_-"))^1
-    local path      = C(((1-P('/'))^0 * P('/'))^1)
+    local slash     = P('/')
+    local name      = (R("az","AZ","--","__"))^1
+    local path      = C(((1-slash)^0 * slash)^1)
     local argument  = P { "(" * C(((1 - S("()")) + V(1))^0) * ")" }
     local action    = Cc(1) * path * C(name) * argument
     local attribute = Cc(2) * path * P('@') * C(name)
+    local direct    = Cc(3) * Cc("../*") * slash^0 * C(name) * argument
 
-    local parser    = action + attribute
+    local parser    = direct + action + attribute
 
     local filters          = xml.filters
     local attribute_filter = xml.filters.attributes
     local default_filter   = xml.filters.default
 
+    -- todo: also hash, could be gc'd
+
     function xml.filter(root,pattern)
         local kind, a, b, c = parser:match(pattern)
-        if kind == 1 then
+--~ if xml.trace_lpath then
+--~     print(pattern,kind,a,b,c)
+--~ end
+        if kind == 1 or kind == 3 then
             return (filters[b] or default_filter)(root,a,c)
         elseif kind == 2 then
             return attribute_filter(root,a,b)
@@ -1429,12 +1647,14 @@ do
     <p>The following functions collect elements and texts.</p>
     --ldx]]--
 
+    -- still somewhat bugged
+
     function xml.collect_elements(root, pattern, ignorespaces)
         local rr, dd = { }, { }
         traverse(root, lpath(pattern), function(r,d,k)
             local dk = d and d[k]
             if dk then
-                if ignorespaces and type(dk) == "string" and dk:find("^%s*$") then
+                if ignorespaces and type(dk) == "string" and dk:find("[^%S]") then
                     -- ignore
                 else
                     local n = #rr+1
@@ -1467,6 +1687,24 @@ do
         return t
     end
 
+    function xml.collect_tags(root, pattern, nonamespace)
+        local t = { }
+        xml.traverse(root, xml.lpath(pattern), function(r,d,k)
+            local dk = d and d[k]
+            if dk and type(dk) == "table" then
+                local ns, tg = e.ns, e.tg
+                if nonamespace then
+                    t[#t+1] = tg -- if needed we can return an extra table
+                elseif ns == "" then
+                    t[#t+1] = tg
+                else
+                    t[#t+1] = ns .. ":" .. tg
+                end
+            end
+        end)
+        return #t > 0 and {}
+    end
+
     --[[ldx--
     <p>Often using an iterators looks nicer in the code than passing handler
     functions. The <l n='lua'/> book describes how to use coroutines for that
@@ -1920,6 +2158,8 @@ do if unicode and unicode.utf8 then
         return char(tonumber(s,16))
     end
 
+    local entities = xml.entities -- global entities
+
     function utfize(root)
         local d = root.dt
         for k=1,#d do
@@ -1937,8 +2177,6 @@ do if unicode and unicode.utf8 then
 
     xml.utfize = utfize
 
-    local entities = xml.entities
-
     local function resolve(e) -- hex encoded always first, just to avoid mkii fallbacks
         if e:find("#x") then
             return char(tonumber(e:sub(3),16))
@@ -1953,20 +2191,24 @@ do if unicode and unicode.utf8 then
         end
     end
 
-    function xml.resolve_entities(root)
-        local d = root.dt
-        for k=1,#d do
-            local dk = d[k]
-            if type(dk) == "string" then
-                if dk:find("&.-;") then
-                    d[k] = dk:gsub("&(.-);",resolve)
+    local function resolve_entities(root)
+        if not root.special or root.tg == "@rt@" then
+            local d = root.dt
+            for k=1,#d do
+                local dk = d[k]
+                if type(dk) == "string" then
+                    if dk:find("&.-;") then
+                        d[k] = dk:gsub("&(.-);",resolve)
+                    end
+                else
+                    resolve_entities(dk)
                 end
-            else
-                utfize(dk)
             end
         end
     end
 
+    xml.resolve_entities = resolve_entities
+
     function xml.utfize_text(str)
         if str:find("&#") then
             return (str:gsub("&#x(.-);",toutf))
@@ -1991,6 +2233,18 @@ do if unicode and unicode.utf8 then
         end
     end
 
+    -- experimental, this will be done differently
+
+    function xml.merge_entities(root)
+        local documententities = root.entities
+        local allentities = xml.entities
+        if documententities then
+            for k, v in pairs(documententities) do
+                allentities[k] = v
+            end
+        end
+    end
+
 end end
 
 --  xml.set_text_cleanup(xml.show_text_entities)
@@ -2026,3 +2280,14 @@ end end
 --~     <windows>my secret</mouse>
 --~ </story>
 --~ ]]
+
+--~ x = xml.convert([[
+--~     <a><b n='01'>01</b><b n='02'>02</b><x>xx</x><b n='03'>03</b><b n='04'>OK</b></a>
+--~ ]])
+--~ xml.xshow(xml.first(x,"b[tag(2) == 'x']"))
+--~ xml.xshow(xml.first(x,"b[tag(1) == 'x']"))
+--~ xml.xshow(xml.first(x,"b[tag(-1) == 'x']"))
+--~ xml.xshow(xml.first(x,"b[tag(-2) == 'x']"))
+
+--~ print(xml.filter(x,"b/tag(2)"))
+--~ print(xml.filter(x,"b/tag(1)"))