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Clean up define/contract's description a bit, and avoid leaning on

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with-contract as much.

svn: r13693
This commit is contained in:
Stevie Strickland 2009-02-17 14:30:00 +00:00
parent 88075e2e50
commit 7920cc48a3
1 changed files with 9 additions and 8 deletions
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17
collects/scribblings/reference/contracts.scrbl
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@ -694,15 +694,16 @@ within the @scheme[with-contract] @scheme[body] will use the
@defform*[[(define/contract id contract-expr init-value-expr)
(define/contract (head args) contract-expr body ...+)]]{
Works like @scheme[define], except that the contract
@scheme[contract-expr] is attached to the bound value.
@scheme[contract-expr] is attached to the bound value. For the
definition of @scheme[head] and @scheme[args], see @scheme[define].
The @scheme[define/contract] form treats individual definitions as
units of blame. The definition itself is responsible for positive
(co-variant) positions of the contract and each reference to
@scheme[id] (including those in the initial value expression) must
meet the negative positions of the contract. It is equivalent to
wrapping a single @scheme[define] with a @scheme[with-contract] form
that pairs the @scheme[contract-expr] with the bound identifier.}
The @scheme[define/contract] form treats the individual definition as
a contract region. The definition itself is responsible for positive
(co-variant) positions of the contract and references to
@scheme[id] outside of the definition must meet the negative
positions of the contract. Since the contract boundary is
between the definition and the surrounding context, references to
@scheme[id] inside the @scheme[define/contract] form are not checked.}
@defform*[[(contract contract-expr to-protect-expr
positive-blame-expr negative-blame-expr)