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document apply/c and memory/c

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svn: r16638
This commit is contained in:
Sam Tobin-Hochstadt 2009-11-09 17:47:49 +00:00
parent ebe2e5ba09
commit 4e7184715b
1 changed files with 31 additions and 0 deletions
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31
collects/unstable/scribblings/poly-c.scrbl
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@ -30,3 +30,34 @@ positive position flow out of the corresponding negative position.
(f 17)
]
}
@defproc[(apply/c [cnt any/c]
[#:name name any/c
(build-compound-type-name 'apply/c c)]) contract?]{
Produces a procedure contract that is like @scheme[cnt], but any delayed
evalutation in @scheme[cnt] is re-done on every
application of the contracted function.
}
@defproc[(memory/c [#:name name any/c "memory/c"]
[#:from from any/c (format "~a:from" name)]
[#:to to any/c (format "~a:to" name)]
[#:weak weak? any/c #t]
[#:equal equal (or/c 'eq 'eqv 'equal) 'eq]
[#:table make-table (-> hash?)
(case equal
[(eq) (if weak? make-weak-hasheq make-hasheq)]
[(eqv) (if weak? make-weak-hasheqv make-hasheqv)]
[(equal) (if weak? make-weak-hash make-hash)])]
)
(values flat-contract? flat-contract?)]{
Produces a pair of contracts. The first contract remembers all values
that flow into it, and rejects nothing. The second accepts only
values that have previously been passed to the first contract.
If @scheme[weak?] is not @scheme[#f], the first contract holds onto
the values only weakly. @scheme[from] and @scheme[to] are the names
of the of the two contracts. }