chickadee » srfi-135 » textual-filter

(textual-filter pred textual [start end]) → textprocedure
(textual-remove pred textual [start end]) → textprocedure

Filter the given subtext of textual, retaining only those characters that satisfy / do not satisfy pred.

If textual is a string, then that string does not share any storage with the result, so subsequent mutation of that string will not affect the text returned by these procedures. If textual is a text, the result shares storage with that text whenever sharing would be space-efficient.