SWI-Prolog -- re_matchsub/4

Documentation
- Reference manual
- Packages
  - SWI-Prolog Regular Expression library
    - library(pcre): Perl compatible regular expression matching for SWI-Prolog

Availability::- use_module(library(pcre)).(can be autoloaded)

[semidet]re_matchsub(+Regex, +String, -Sub:dict, +Options)

Match String against Regex. On success, Sub is a dict containing integer keys for the numbered capture group and atom keys for the named capture groups. The associated value is determined by the capture_type(Type) option passed to re_compile/3, may be specified using flags if Regex is of the form Pattern/Flags and may be specified at the level of individual captures using a naming convention for the caption name. See re_compile/3 for details.

The example below exploits the typed groups to parse a date specification:

?- re_matchsub("(?<date> (?<year_I>(?:\\d\\d)?\\d\\d) -
                (?<month_I>\\d\\d) - (?<day_I>\\d\\d) )"/e,
               "2017-04-20", Sub, []).
Sub = re_match{0:"2017-04-20", date:"2017-04-20",
               day:20, month:4, year:2017}.

`Options`	Only execution options are processed. See re_match/3 for the set of options. Compilation options must be passed as‘/flags` to `Regex`.
`Regex`	See re_match/2 for a description of this argument.