Match a string against a regular expression, which is parsed at macroexpansion time.
(match pattern str :case-insens nil :legible t) --> match-result
This macro runs parse at macroexpansion time to create a regular expression object that is "compiled in" to the function, so that parsing doesn't need to be done every time. This means that the input pattern must be a string literal and legible must be a Boolean literal. If the regular expression is malformed, it will result in an error at macroexpansion time.