[R6RS] What are predicates?
William D Clinger
will at ccs.neu.edu
Sun Jun 25 14:45:10 EDT 2006
> Some of the list procedures we're adding accept predicates as
> arguments. As per R5RS, a predicate is a procedure returning a
> boolean value, i.e. #t or #f. However, procedures like `exists' could
> also handle any true value returned by the predicate. Should they?
> (I'm thinking yes.)
That would be far superior to requiring them to raise
an exception if the predicate were to return something
other than a boolean (e.g. memq).
More information about the R6RS