On 5/1/2020 11:38 PM, Aditya Mahajan wrote:
On Fri, 1 May 2020, Hans Hagen wrote:

On 5/1/2020 6:12 AM, Jairo A. del Rio wrote:
I've adapted the following code to make mazes in LuaLaTeX and ConTeXt: https://www.rosettacode.org/wiki/Maze_generation#Lua

I defined a modified version to make content visible to TeX and I saved in a file named maze.lua:

function make_maze_tex(w, h, m)
   w = w or 16
   h = h or 8

   local map = initialize_grid(w*2+1, h*2+1)

   function walk(x, y)
     map[y][x] = false

     local d = { 1, 2, 3, 4 }
     shuffle(d)
     for i, dirnum in ipairs(d) do
       local xx = x + dirs[dirnum].x
       local yy = y + dirs[dirnum].y
       if map[yy] and map[yy][xx] then
         map[avg(y, yy)][avg(x, xx)] = false
         walk(xx, yy)
       end
     end
   end

   walk(math.random(1, w)*2, math.random(1, h)*2)

...ext/tex/texmf-context/tex/context/base/mkiv/supp-ran.lua:30: C stack overflow Why does it happen? I guess it has something to do with math.randomseed, but I don't know how to avoid this error message.
no, it's just lua running out of stack space so it depends on the binary (and als the initial random value)

But why is it running out of stack? Isn't the walk function tail recursive, in which case it should not cause a stack overflow (https://www.lua.org/pil/6.3.html).
not really tail recursive: that is only true when it's the last action and return is used and it nests very deep

function foo(...)
  ...
  return foo(...)
end

versus

function foo(...)
  ...
  if something then
     foo(...)
  end
end

Hans

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                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
       tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
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