generator/xml.lua

   1 #!/usr/bin/lua
   2
   3 --[[
   4
   5 Copyright (c) 2007-2008 Mauro Iazzi
   6
   7 Permission is hereby granted, free of charge, to any person
   8 obtaining a copy of this software and associated documentation
   9 files (the "Software"), to deal in the Software without
  10 restriction, including without limitation the rights to use,
  11 copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 copies of the Software, and to permit persons to whom the
  13 Software is furnished to do so, subject to the following
  14 conditions:
  15
  16 The above copyright notice and this permission notice shall be
  17 included in all copies or substantial portions of the Software.
  18
  19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  20 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  21 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  22 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  23 HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  24 WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  26 OTHER DEALINGS IN THE SOFTWARE.
  27
  28 --]]
  29
  30
  31 local parseargs, collect
  32
  33 local escapes = {
  34         gt = '>',
  35         lt = '<',
  36 }
  37
  38 local strip_escapes = function (s)
  39         s = string.gsub(s, '&(%a+);', escapes)
  40         return s
  41 end
  42
  43
  44 function parseargs(s)
  45         local arg = {}
  46         string.gsub(s, "([%w_]+)=([\"'])(.-)%2", function (w, _, a)
  47                 arg[strip_escapes(w)] = strip_escapes(a)
  48         end)
  49         return arg
  50 end
  51
  52 function collect(s)
  53         local stack = {}
  54         local index = {}
  55         local top = {}
  56         table.insert(stack, top)
  57         local ni,c,label,xarg, empty
  58         local i, j = 1, 1
  59         while true do
  60                 ni,j,c,label,xarg, empty = string.find(s, "<(%/?)(%w+)(.-)(%/?)>", j)
  61                 if not ni then break end
  62                 local text = string.sub(s, i, ni-1)
  63                 if not string.find(text, "^%s*$") then
  64                         table.insert(top, strip_escapes(text))
  65                 end
  66                 if empty == "/" then  -- empty element tag
  67                         table.insert(top, {label=label, xarg=parseargs(xarg), empty=1})
  68                 elseif c == "" then   -- start tag
  69                         top = {label=label, xarg=parseargs(xarg)}
  70                         table.insert(stack, top)   -- new level
  71                 else  -- end tag
  72                         local toclose = table.remove(stack)  -- remove top
  73                         top = stack[#stack]
  74                         if #stack < 1 then
  75                                 error("nothing to close with "..label)
  76                         end
  77                         if toclose.label ~= label then
  78                                 error("trying to close "..toclose.label.." with "..label)
  79                         end
  80                         table.insert(top, toclose)
  81                         toclose.parent = top
  82                         toclose.index = #top
  83                         index[toclose] = true
  84                 end
  85                 i = j+1
  86         end
  87         local text = string.sub(s, i)
  88         if not string.find(text, "^%s*$") then
  89                 table.insert(stack[#stack], text)
  90         end
  91         if #stack > 1 then
  92                 error("unclosed "..stack[stack.n].label)
  93         end
  94         return stack[1], index
  95 end
  96
  97 return collect