2 Contract

(require (planet dvanhorn/ralist:3:2/contract))

Just like (planet dvanhorn/ralist:3:2), but with contracts.

Returns a flat contract that requires the input to have a count equal to n.

Returns a flat contract that requires the input to have a count greater than n.

x : any/c

Returns a flat contract that requires nothing of its input, and returns x, i.e. it produces a contract for the predicate (lambda (_) x).

Returns a flat contract that requires its input to be a procedure accepting at least n arguments, i.e. it produces a contract for the predicate,

(lambda (x)
(and (procedure? x)
(procedure-arity-includes? x n)))