1 Exception utilities
2 Number utilities
3 String utilities
4 Bytes utilities
5 Symbol utilities
6 List utilities
7 PLT 4x hash utilities
8 PLT 3x hash utilities
9 URL utilities
10 Contract utilities
11 File and path utilities
12 Parameter utilities
13 Syntax utilities
14 SRFI19 time utilities
15 Scribble utilities
16 Generators
17 Generators (short names)
18 Pipelines
19 Write-through cache
20 Yieldable procedures
21 Debugging tools
22 Profiling tools
23 Logging tools
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arity/ c


10 Contract utilities

 (require (planet untyped/unlib/contract))

Utilities for use with the PLT contract library.

(arity/c arity)  flat-contact?

  arity : natural?

Returns a flat contract that requires the input to be procedure that accepts the specified number of (non-keyword) arguments. The procedure may, in addition, accept more and/or fewer arguments and any number of keyword arguments.


  > (define c (arity/c 2))

  > (contract-first-order-passes? c (lambda (a b) (void)))


  > (contract-first-order-passes? c (lambda (a b c) (void)))


  > (contract-first-order-passes? c (lambda (a [b #f]) (void)))


  > (contract-first-order-passes? c (lambda (a b #:c c) (void)))


  > (contract-first-order-passes? c (lambda (a #:b b) (void)))