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1 point by almkglor 5726 days ago | link | parent

If I wanted to represent a matrix of objects.... say a world populated by virtual creatures... I might prefer to predefine the size of the world and identify creature locations using numeric coordinates. I might then want to use an array of arrays to represent the world ^^. I might even abstract away the position of an object using a "location" type composed of a pair of numeric coordinates and a reference to the world, then have "north" and "east" etc. functions to get locations in those directions. Then I might get the reference or set the reference of a location object and thus query and/or change the state of the creatures in that world.... ^^

In Arc-F for example I might use:

  (using <vector>v2) ; vector and vector-of

  (def make-world (xwidth yheight)
    (apply vector
           (w/collect:for i 0 (- xwidth)
             (collect:vector-of yheight nil))))

  ; create a location type
  (def location (world x y)
    (annotate 'location
      (list world x y)))

  (defcall location (r)
    (let (world x y) r
      (world.x y)))

  (defm sref ((t loc location) val)
    (let (world x y) (rep loc)
      (sref world.x val y)))

  ; 0---> INF
  ; |
  ; |
  ; v
  ; INF
  (def south (loc (o step 1))
    (err "'north and 'south expect a location"))
  (defm south ((t loc location) (o step 1))
    (let (world x y) (rep loc)
      (location world x (+ y step))))

  (def north (loc (o step 1))
    (south loc (- step)))

  (def east (loc (o step 1))
    (err "'east and 'west expect a location"))
  (defm east ((t loc location) (o step 1))
    (let (world x y) (rep loc)
      (location world (+ x step) y)))

  (def west (loc (o step 1))
    (east loc (- step)))
^^


1 point by bOR_ 5726 days ago | link

just a random hypothetical situation eh? ;).

I should put some more work into it. The good news is that I just found a nice and simple editor that plays well with arc-f on windows (LispIDE - http://www.daansystems.com/lispide/)

btw. arc-f arc.bat doesn't play nice yet with "Program Files" type of directories. Works fine in C:\arc-f.

Got this error:

> default-load-handler: cannot open input file: "C:\Program" (The system cannot find the file specified.; errno=2)

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1 point by almkglor 5725 days ago | link

> just a random hypothetical situation eh? ;)

Of course, of course ^^

> btw. arc-f arc.bat doesn't play nice yet with "Program Files" type of directories.

Huh. I guess I really should fix my WinXP computer at some point in time T.T

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