Difference between revisions of "Thunks and Streams Assignment"
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=Code To Use= | =Code To Use= | ||
[https://docs.racket-lang.org/reference/define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define-syntax%29%29 define-syntax] | [https://docs.racket-lang.org/reference/define.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._define-syntax%29%29 define-syntax] | ||
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| + | [https://docs.racket-lang.org/reference/lambda.html?q=lambda#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._lambda%29%29 lambda] | ||
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| + | [https://docs.racket-lang.org/reference/procedures.html#%28def._%28%28quote._~23~25kernel%29._procedure~3f%29%29 procedure?] | ||
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| + | [https://docs.racket-lang.org/reference/procedures.html?q=procedure-arity#%28def._%28%28quote._~23~25kernel%29._procedure-arity%29%29 procedure-arity] | ||
=Code To Implement= | =Code To Implement= | ||
Revision as of 18:05, 2 July 2019
Code To Use
Code To Implement
Thunk Utilities
define a function thunk? which returns #t if the specified parameter is a thunk, #f otherwise.
define a macro thunk which creates thunk
define a function dethunk which takes a thunk parameter th and returns the result of invoking th.
Stream Utilities
define a function plausible-stream? which returns #t if the specified parameter is a thunk which when invoked returns a pair whose cdr is a thunk, #f otherwise.
WARNING: what could happen if you called plausible-stream? recursively on the cdr?
define a function next-value-from-stream which takes a stream parameter and returns the next value of that stream.
define a function next-stream-from-stream which takes a stream parameter and returns the next stream of that stream.
define a function stream-cons which takes two parameters value and stream-prime. if the specified stream-prime parameter is not a thunk then an error should be raised:
(raise (error "not a thunk" stream-prime))
WARNING: what could happen if you called plausible-stream? on stream-prime?
Stream App
define flip-flop-stream which produces #t #f #t #f #t #f #t #f...
