8.11 Legacy Contracts (original) (raw)

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8.11 Legacy Contracts🔗ℹ

procedure(make-proj-contract name proj first-order) → contract?
name : any/c
proj : (or/c (-> any/c any/c (list/c any/c any/c) contact? (-> any/c any/c)) (-> any/c any/c (list/c any/c any/c) contact? boolean? (-> any/c any/c)))
first-order : (-> any/c boolean?)

Builds a contract using an old interface.

Modulo errors, it is equivalent to:

(make-contract
#:name name
#:first-order first-order
#:projection
(cond
[(procedure-arity-includes? proj 5)
(lambda (blame)
(proj (blame-positive blame)
(blame-negative blame)
(list (blame-source blame) (blame-value blame))
(blame-contract blame)
(not (blame-swapped? blame))))]
[(procedure-arity-includes? proj 4)
(lambda (blame)
(proj (blame-positive blame)
(blame-negative blame)
(list (blame-source blame) (blame-value blame))
(blame-contract blame)))]))

procedure(raise-contract-error val src pos name fmt arg ...) → any/c
val : any/c
src : any/c
pos : any/c
name : any/c
fmt : string?
arg : any/c

Calls raise-blame-error after building a blame struct from the val, src, pos, and name arguments. The fmt string and following arguments are passed toformat and used as the string in the error message.

procedure(contract-proc c)
→ (->* (symbol? symbol? (or/c syntax? (list/c any/c any/c))) (boolean?) (-> any/c any))
c : contract?

Constructs an old-style projection from a contract.

The resulting function accepts the information that is in a blamestruct and returns a projection function that checks the contract.

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