-- treetex.lua: derivation trees and functions to convert them to TeX.
-- This file:
--   http://angg.twu.net/dednat5/treetex.lua.html
--   http://angg.twu.net/dednat5/treetex.lua
--                    (find-dn5 "treetex.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
-- Version: 2011apr04
-- License: GPL3
--

-- intersecting   (find-dn4 "dednat4.lua" "tree-lib")
-- tatsuta        (find-dn4 "dednat4.lua" "tree-out")
-- paultaylor

require "eoo"       -- (find-dn5 "eoo.lua")

TreeNode = Class {
  type    = "TreeNode",
  __index = {
    hasbar    = function (tn) return tn.bar ~= nil end,
    barchar   = function (tn) return tn.bar end,
    TeX_root  = function (tn) return tn[0] end,
    TeX_label = function (tn) return tn.label end,
    nhyps     = function (tn) return #tn end,
    hypslist  = function (tn) return tn end,
  },
}

TeX_subtree_tatsuta = function (tn, i_)
    if not tn:hasbar() then
      return i_.."\\mathstrut "..tn:TeX_root()
    else
      local r_ = tn:TeX_root()
      local b_ = tn:barchar()
      local l_ = tn:TeX_label()
      local h_ = tn:hypslist()
      local r  = "\\mathstrut "..r_
      local b  = ({["-"]="", ["="]="=", [":"]="*"})[b_]
      local l  = (l_ and "[{"..l_.."}]") or ""
      local i  = i_.." "
      local f  = function (tn) return TeX_subtree_tatsuta(tn, i) end
      local h  = mapconcat(f, h_, " &\n")
      return i_.."\\infer"..b..l.."{ "..r.." }{\n"..h.." }"
    end
  end
TeX_deftree_tatsuta = function (tn, name, link)
    return "\\defded{"..name.."}{"..(link or "").."\n"..
           TeX_subtree_tatsuta(tn, " ").." }"
  end

TreeNode.__index.TeX_subtree = TeX_subtree_tatsuta
TreeNode.__index.TeX_deftree = TeX_deftree_tatsuta




-- dump-to: tests
--[==[
* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
require "treetex"
TN = function (root, b, l, ...)
    return TreeNode {[0]=root, bar=b, label=l, ...}
  end
T = TN("f(1+2+3)", "-", "app",
       TN("f"),
       TN("1+2+3", "=", nil,
          TN"1",
          TN"2",
          TN"3"))
print(T:TeX_subtree("  "))
print(T:TeX_deftree("f(1+2+3)"))

-- Here's a typical TreeNode structure:
PP(T)
-- {0="f(1+2+3)",
--    1={0="f"},
--    2={0="1+2+3",
--         1={0="1"},
--         2={0="2"},
--         3={0="3"},
--       "bar"="="},
--  "bar"="-",
--  "label"="app"}

--]==]


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