Pattern Matching for Ports🔗ℹ

pat must be a head pattern, which may be specified as follows:

• (byte tail ...) — matches a single byte.

• (bytes amt tail ...) — matches a sequence of exactly amt bytes.

• (char tail ...) — matches a single UTF-8 character.

• (string len tail ...) — matches a sequence of exactly len characters.

• (regexp pattern tail ...) — matches a sequence of characters or bytes which match pattern. The pattern must match immediately to count as a match (as if it began with ^).

• eof — matches end-of-file.

• (seq head ...) — matches each head in sequence.

Head patterns recognize one or more datums, which may be matched against tail patterns:

• (app proc tail) — calls proc with the matched datum, and matches the result against tail.

• (? proc tail ...) — matches only if proc returns true when applied to the matched datum.

• id — binds id to the matched datum.

Patterns may be combined as follows:

• (and pat ...) — matches only if every pat matches.

• (or pat ...) — matches if at least one pat matches.

• _ — matches anything.