cd70055bc7
Renamed files: constanten→constants, adt-positie→adt-position, adt-doolhof→adt-maze, adt-sleutel→adt-key, adt-tijdslimiet→adt-timer, adt-teken→adt-draw, adt-spel→adt-game. All message names, variables, comments, and tests converted to English. Also fixed counter location bug (time-label x/y were swapped). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
51 lines
1.6 KiB
Racket
51 lines
1.6 KiB
Racket
#lang r7rs
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; Position ADT ;;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; A position represents a location on the logical maze grid.
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;; Coordinates are in grid units (row, col), NOT pixels.
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(define-library (pacman-project adt-position)
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(import (scheme base))
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(export make-position)
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(begin
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;; make-position :: number, number -> position
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;; Creates a new position object with row and column on the grid.
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(define (make-position row col)
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;; row! :: number -> /
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(define (row! new-row)
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(set! row new-row))
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;; col! :: number -> /
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(define (col! new-col)
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(set! col new-col))
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;; equal? :: position -> boolean
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;; Checks whether two positions have the same coordinates.
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(define (equal? other)
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(and (= row (other 'row))
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(= col (other 'col))))
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;; move :: number, number -> position
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;; Returns a new position shifted by delta-row and delta-col.
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(define (move delta-row delta-col)
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(make-position (+ row delta-row)
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(+ col delta-col)))
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;; dispatch-position :: symbol -> any
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(define (dispatch-position msg)
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(cond ((eq? msg 'row) row)
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((eq? msg 'col) col)
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((eq? msg 'row!) row!)
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((eq? msg 'col!) col!)
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((eq? msg 'equal?) equal?)
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((eq? msg 'move) move)
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(else (error "Position ADT -- Unknown message:" msg))))
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dispatch-position)))
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