-- This file:
--   http://angg.twu.net/LUA/EScript.lua.html
--   http://angg.twu.net/LUA/EScript.lua
--           (find-angg "LUA/EScript.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- Parse e-scripts.
--
-- (defun e () (interactive) (find-angg "LUA/EScript.lua"))

-- (find-es "lpeg" "globals")
require "lpeg"
B,C,P,R,S,V = lpeg.B,lpeg.C,lpeg.P,lpeg.R,lpeg.S,lpeg.V
Cb,Cc,Cf,Cg = lpeg.Cb,lpeg.Cc,lpeg.Cf,lpeg.Cg
Cp,Cs,Ct    = lpeg.Cp,lpeg.Cs,lpeg.Ct
Carg,Cmt    = lpeg.Carg,lpeg.Cmt

-- (find-es "lpeg" "lpeg-quickref")
p_tagchar  = R"!~" - S'"'
p_tag      = p_tagchar^1
p_anchor   = P"«"     * p_tag:C() * P"»"
p_to       = P'(to "' * p_tag:C() * '")'
p_anchorto = R" ~"^0 * p_anchor * S" \t"^0 * p_to
p_headermidline  = P'# ' * ((1-P"\n")^0):C() * P'\n'
p_header         = P'#####\n#\n' * p_headermidline * p_headermidline * P"#\n#####\n\n"
p_headeranchorto = p_header * p_anchorto

Lines = Class {
  type = "Lines",
  from = function (bigstr)
      local n,line,ltob,btol = 0, {}, {}, {}
      for pos,li in bigstr:gmatch("()([^\n]-)\n") do
        n = n + 1
        line[n] = li
        ltob[n] = pos
        btol[pos] = n
      end
      return Lines {bigstr=bigstr, n=n, line=line, ltob=ltob, btol=btol}
    end,
  read = function (fname)
      local lis = Lines.from(ee_readfile(fname))
      lis.fname = fname
      return lis
    end,
  __tostring = function (lis)
      return format("Lines object with %d lines", lis.n)
    end,
  __index = {
    fline = function (lis, linen)
        return format('(find-fline "%s" %d)', lis.fname, linen)
      end,
    lmatch = function (lis, linen, lpegpat)
        return lpegpat:match(lis.bigstr, lis.ltob[linen])
      end,
    isindex = function (lis, linen)
        local dtag,tag = lis:lmatch(linen, p_anchorto)
        if dtag and dtag == "."..tag then return tag end
      end,
    isheader = function (lis, linen)
        local title,date,tag,dtag = lis:lmatch(linen, p_headeranchorto)
        if title and dtag == "."..tag then return tag,title,date end
      end,
    --
    error_index_twice = function (lis, tag, line1, line2)
        local firstline = format('The tag "%s" appears twice in the index:', tag)
        local link1 = lis:fline(line1)
        local link2 = lis:fline(line2)
        return firstline .."\n".. link1 .."\n".. link2
      end,
    error_block_twice = function (lis, tag, line1, line2)
        local firstline = format('The tag "%s" appears twice in blocks:', tag)
        local link1 = lis:fline(line1)
        local link2 = lis:fline(line2)
        return firstline .."\n".. link1 .."\n".. link2
      end,
    getindex = function (lis)
        local index, n = {}, 0
        for linen=1,lis.n do
          local tag = lis:isindex(linen)
          if tag then
            if index[tag] then
              print(lis:error_index_twice(tag, index[tag].linen, linen))
            end
            n = n + 1
            local A = {n=n, linen=linen, tag=tag}
            index[tag] = A
            index[n]   = A
          end
        end
        return index
      end,
    getblocks = function (lis)
        local blocks = {}
        for linen=1,lis.n do
          local tag,title,date = lis:isheader(linen)
          if tag then
            if blocks[tag] then
              print(lis:error_block_twice(tag, blocks[tag].linen, linen))
            end
            local n = #blocks + 1
            local block = {n=n, linen=linen, tag=tag, title=title, date=date}
            blocks[tag] = block
            blocks[n]   = block
          end
        end
        return blocks
      end,
  },
}



--[[
* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
dofile "EScript.lua"
-- (find-es "lpeg")
lis = Lines.read "~/e/lpeg.e"
lis = Lines.read "~/e/lua5.e"
lis = Lines.read "~/e/maxima.e"
= lis
= lis.n

= lis:fline(274)
     lis:getindex()
     lis:getblocks()
PPPV(lis:getindex())
PPPV(lis:getblocks())


--]]



EScript = Class {
  type = "EScript",
  from = function (fname)
      local bigstr = ee_readfile(fname)
      return EScript {fname=fname, bigstr=bigstr}
    end,
  __tostring = function (es) return "fname: "..es.fname end,
  __index = {
  },
}





-- Local Variables:
-- coding:  utf-8-unix
-- End: