anchored(Bool)

Force pattern anchoring

bsr(Mode)

If anycrlf, \R only matches CR, LF or CRLF. If unicode, \R matches all Unicode line endings.

caseless(Bool)

If true, do caseless matching.

dollar_endonly(Bool)

If true, $ not to match newline at end

dotall(Bool)

If true, . matches anything including NL

dupnames(Bool)

If true, allow duplicate names for subpatterns

extended(Bool)

If true, ignore white space and # comments

extra(Bool)

If true, PCRE extra features (not much use currently)

firstline(Bool)

If true, force matching to be before newline

compat(With)

If javascript, JavaScript compatibility

multiline(Bool)

If true, ^ and $ match newlines within data

newline(Mode)

If any, recognize any Unicode newline sequence, if anycrlf (default), recognize CR, LF, and CRLF as newline sequences, if cr, recognize CR, if lf, recognize LF and finally if crlf recognize CRLF as newline.

ucp(Bool)

If true, use Unicode properties for \d, \w, etc.

ungreedy(Bool)

If true, invert greediness of quantifiers

In addition to the options above that directly map to pcre flags the following options are processed:

optimize(Bool)

If true, study the regular expression.

capture_type(+Type)

How to return the matched part of the input and possibly captured groups in there. Possible values are:

string

Return the captured string as a string (default).

atom

Return the captured string as an atom.

range

Return the captured string as a pair Start-Length. Note the we use Start-Length` rather than the more conventional Start-End to allow for immediate use with sub_atom/5 and sub_string/5.

term

Parse the captured string as a Prolog term. This is notably practical if you capture a number.

The capture_type specifies the default for this pattern. The interface supports a different type for each named group using the syntax (?<name_T>...), where T is one of S (string), A (atom), I (integer), F (float), N (number), T (term) and R (range). In the current implementation I, F and N are synonyms for T. Future versions may act different if the parsed value is not of the requested numeric type.