caac996acd
New structure groups all ADT modules under adt/ directory, removing redundant adt- prefix from filenames. Library names now read as (pacman-project adt position) etc. All imports updated accordingly. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
56 lines
1.9 KiB
Racket
56 lines
1.9 KiB
Racket
#lang r7rs
|
|
|
|
(#%require (only racket/base random))
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
;; Key ADT ;;
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
;; The key is placed at a random coin position in the maze. When Pac-Man
|
|
;; picks it up, doors can be opened. Contains NO graphics code.
|
|
|
|
(define-library (pacman-project adt key)
|
|
(import (scheme base)
|
|
(pacman-project constants)
|
|
(pacman-project adt position))
|
|
(export make-key)
|
|
|
|
(begin
|
|
|
|
;; make-key :: maze -> key
|
|
;; Creates a key and places it at a random coin position.
|
|
(define (make-key maze)
|
|
(let ((position #f)
|
|
(taken? #f))
|
|
|
|
;; place-random! :: -> /
|
|
;; Places the key on a random cell that contains a coin.
|
|
(define (place-random!)
|
|
(let loop ((attempts 0))
|
|
(if (>= attempts max-placement-attempts)
|
|
(error "No valid position found for key")
|
|
(let ((col (random 0 (maze 'cols)))
|
|
(row (random 0 (maze 'rows))))
|
|
(if ((maze 'coin?) row col)
|
|
(begin
|
|
(set! position (make-position row col))
|
|
((maze 'cell-set!) row col cell-type-key))
|
|
(loop (+ attempts 1)))))))
|
|
|
|
;; take! :: -> /
|
|
;; Marks the key as taken.
|
|
(define (take!)
|
|
(set! taken? #t))
|
|
|
|
;; Initialization: place the key immediately on creation.
|
|
(place-random!)
|
|
|
|
;; dispatch-key :: symbol -> any
|
|
(define (dispatch-key msg)
|
|
(cond ((eq? msg 'position) position)
|
|
((eq? msg 'taken?) taken?)
|
|
((eq? msg 'take!) take!)
|
|
(else (error "Key ADT -- Unknown message:" msg))))
|
|
|
|
dispatch-key))))
|