Thunks and Streams Assignment
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...