50.3 Compiling regular expressions

Function: irregex pcre/sre options ...

Function: string->irregex pcre options ...

Function: sre->irregex sre options ...

Compile a regular expression from either a POSIX–style regular expression string (with most PCRE extensions) or an SCSH–style SRE. Return an object representing the compiled regular expression.

There is no (rx ...) syntax to specify the regular expression, we just use normal Scheme lists. Technically a string by itself could be considered a valid SRE, so if we want to just match a literal string we should use something like:

(irregex `(: ,str))

or use the explicit:

(string->irregex str)

The optional options are a list of any of the following symbols, which must be quoted:

i

case-insensitive

match case–insensitively;

m

multi-line

treat string as multiple lines (effects ^ and $);

s

single-line

treat string as a single line (. can match newline);

utf8

UTF-8 mode, assumes strings are byte–strings;

fast

try to optimize the regular expression;

small

try to compile a smaller regular expression.

NOTE The fast and small options may not actually make the compiled expression any faster or smaller at the moment.