-- This file:
--   https://anggtwu.net/LUA/DiagStacks1.lua.html
--   https://anggtwu.net/LUA/DiagStacks1.lua
--           (find-angg "LUA/DiagStacks1.lua")
-- Author: Eduardo Ochs <eduardoochs@gmail.com>
--
-- This file implements the stacks used by: 
--   (find-dn6 "diagforth.lua" "diagram")
--   (find-dn6 "diagforth.lua" "enddiagram")
--
-- The main stack, `ds', is based on the Forth data stack - see:
--   (find-miniforthgempage 3  "DS={ 5 }")
--
-- The items in `ds' are usually nodes and arrows,
-- that are also kept in the tables `nodes' and `arrows',
-- and are reset every time that we run "diagram" and "enddiagram".
--
-- There is also a "metastack" called `depths', used by "((" and "))":
--   (find-dednatslides2018page 10)
--   (find-dednatslides2018text 10)
--
-- Based on: (find-dn6 "diagstacks.lua")
--  Used by: (find-angg "LUA/DiagForth1.lua")

-- «.nodes»		(to "nodes")
-- «.nodes-test»	(to "nodes-test")
-- «.arrows-test»	(to "arrows-test")


require "Stack1"        -- (find-angg "LUA/Stack1.lua")

ds     = Stack.new()
depths = Stack {ds=ds}  -- (find-angg "LUA/Stack1.lua" "Stack" "metastacks")


--                  _           
--  _ __   ___   __| | ___  ___ 
-- | '_ \ / _ \ / _` |/ _ \/ __|
-- | | | | (_) | (_| |  __/\__ \
-- |_| |_|\___/ \__,_|\___||___/
--                              
-- «nodes»  (to ".nodes")
-- See: (find-angg "LUA/DiagForth1.lua" "DiagForth" "ds:push(nodes[word])")
--      (find-angg "LUA/DiagForth1.lua" "2D-and-2Dx" "storenode")
--
nodes = VTable {}               -- has numeric and string indices
storenode = function (node)
    table.insert(nodes, node)
    node.noden = #nodes         -- ".noden" acts as a numeric id.
    if node.tag then            --   ".tag" acts as a string  id.
      nodes[node.tag] = node    -- "midpoint" creates nodes without ".tag"s.
    end
    return node
  end

-- «nodes-test»  (to ".nodes-test")
--[[
 (eepitch-lua51)
 (eepitch-kill)
 (eepitch-lua51)
dofile "DiagStacks1.lua"
ds:push(storenode {x=4, y=5, tag="A"})
ds:push(storenode {x=6, y=7, tag="B"})
ds:push(storenode {x=8, y=9})
= nodes

--]]



-- «arrows»  (to ".arrows")
-- See: (find-angg "LUA/DiagForth1.lua" "arrows" "storearrow")
--      (find-angg "LUA/DiagForth1.lua" "enddiagram")
--      (find-angg "LUA/DiagTeX1.lua" "diagxy_def_diag")
--
arrows = VTable {}              -- has only numeric indices
storearrow = function (arrow)
    table.insert(arrows, arrow)
    arrow.arrown = #arrows
    return arrow
  end

-- «arrows-test»  (to ".arrows-test")
--[[
 (eepitch-lua51)
 (eepitch-kill)
 (eepitch-lua51)
dofile "DiagStacks1.lua"
dofile "DiagTeX1.lua"
Stack.__index.tostring = mytostringv
ds:push(storenode {x=4, y=5, tag="A"})
ds:push(storenode {x=6, y=7, tag="B"})
ds:push(storenode {x=8, y=9, tag="C"})
ds:push(storearrow(DxyArrow {from=1, to=2, shape="->"}))
ds:push(storearrow(DxyArrow {from=2, to=3, shape="->"}))
= nodes
= arrows
= diagxy_def_diag("Foo")

--]]




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