27.2.5 Predicates

Function: bytevector-u8-null? obj

Return #t if obj is the empty bytevector, otherwise return #f.

Function: %bytevector-s8-every byte/char/char-set/pred bv start past

Function: %bytevector-u8-every byte/char/char-set/pred bv start past

Function: %bytevector-s8-any byte/char/char-set/pred bv start past

Function: %bytevector-u8-any byte/char/char-set/pred bv start past

Macro: bytevector-s8-every byte/char/char-set/pred B

Macro: bytevector-u8-every byte/char/char-set/pred B

Macro: bytevector-s8-any byte/char/char-set/pred B

Macro: bytevector-u8-any byte/char/char-set/pred B

Check to see if the given criteria is true on every/any byte in bv, proceeding from left (index start) to right (index past).

If the selected subvector is empty: the return value is #f.

If byte/char/char-set/pred is a byte, it is tested for equality with the elements of B.

If byte/char/char-set/pred is a character, it is tested for equality with the elements of B.

If byte/char/char-set/pred is a character set, the elements of B are tested for membership in the set.

If byte/char/char-set/pred is a predicate procedure, it is applied to the elements of B. The predicate is “witness–generating”:

• If bytevector-u8-any returns true, the returned true value is the one produced by the application of the predicate.
• If bytevector-u8-every returns true, the returned true value is the one produced by the application of the predicate to the last byte in the subvector.

If the predicate is applied to the final element of the selected subvector, that final application is a tail call.

The names of these procedures do not end with a question mark; this is to indicate that, in the predicate case, they do not return a simple boolean (#t or #f), but a general value.