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>
63 lines
2.2 KiB
Racket
63 lines
2.2 KiB
Racket
#lang r7rs
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; Timer ADT ;;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; Manages the countdown time limit. Contains NO graphics code.
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(define-library (pacman-project adt timer)
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(import (scheme base)
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(pacman-project constants))
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(export make-timer)
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(begin
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;; make-timer :: -> timer
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;; Creates a new timer object.
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(define (make-timer)
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(let ((remaining-time start-time-seconds)
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(time-since-last-tick 0))
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;; decrease! :: number -> /
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;; Decreases time based on elapsed milliseconds.
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(define (decrease! ms)
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(set! time-since-last-tick (+ time-since-last-tick ms))
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(when (>= time-since-last-tick ms-per-second)
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(set! time-since-last-tick 0)
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(when (> remaining-time 0)
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(set! remaining-time (- remaining-time 1)))))
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;; increase! :: -> /
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;; Adds a time bonus (when eating a coin).
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(define (increase!)
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(set! remaining-time (+ remaining-time time-bonus-per-coin)))
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;; time-up? :: -> boolean
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(define (time-up?)
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(= remaining-time 0))
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;; format-time :: -> string
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;; Returns remaining time as "m:ss" string.
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(define (format-time)
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(let* ((minutes (quotient remaining-time 60))
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(seconds (remainder remaining-time 60))
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(min-str (number->string minutes))
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(sec-str (number->string seconds)))
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(string-append min-str
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":"
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(if (< seconds 10)
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(string-append "0" sec-str)
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sec-str))))
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;; dispatch-timer :: symbol -> any
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(define (dispatch-timer msg)
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(cond ((eq? msg 'remaining-time) remaining-time)
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((eq? msg 'decrease!) decrease!)
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((eq? msg 'increase!) increase!)
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((eq? msg 'time-up?) time-up?)
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((eq? msg 'format-time) format-time)
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(else (error "Timer ADT -- Unknown message:" msg))))
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dispatch-timer))))
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