Module Regexp.PCRE.OPTION

Description: contains all option constants

Constant ANCHORED: constant Regexp.PCRE.OPTION.ANCHORED
Description: (from the pcreapi manpage) If this bit is set, the pattern is forced to be "anchored", that is, it is constrained to match only at the first matching point in the string which is being searched (the "subject string"). This effect can also be achieved by appropriate constructs in the pattern itself, which is the only way to do it in Perl.

Constant CASELESS: constant Regexp.PCRE.OPTION.CASELESS
Description: (from the pcreapi manpage) If this bit is set, letters in the pattern match both upper and lower case letters. It is equivalent to Perl's /i option, and it can be changed within a pattern by a (?i) option setting.

Constant DOLLAR_ENDONLY: constant Regexp.PCRE.OPTION.DOLLAR_ENDONLY
Description: (from the pcreapi manpage) If this bit is set, a dollar metacharacter in the pattern matches only at the end of the subject string. Without this option, a dollar also matches immediately before the final character if it is a newline (but not before any other newlines). The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set. There is no equivalent to this option in Perl, and no way to set it within a pattern.

Constant DOTALL: constant Regexp.PCRE.OPTION.DOTALL
Description: (from the pcreapi manpage) If this bit is set, a dot metacharater in the pattern matches all characters, including newlines. Without it, newlines are excluded. This option is equivalent to Perl's /s option, and it can be changed within a pattern by a (?s) option setting. A negative class such as [^a] always matches a newline character, independent of the setting of this option.

Constant EXTENDED

constant Regexp.PCRE.OPTION.EXTENDED

Description

(from the pcreapi manpage) If this bit is set, whitespace data characters in the pattern are totally ignored except when escaped or inside a character class. Whitespace does not include the VT character (code 11). In addition, characters between an unescaped # outside a character class and the next newline character, inclusive, are also ignored. This is equivalent to Perl's /x option, and it can be changed within a pattern by a (?x) option setting.

This option makes it possible to include comments inside complicated patterns. Note, however, that this applies only to data characters. Whitespace characters may never appear within special character sequences in a pattern, for example within the sequence (?( which introduces a conditional subpattern.

Constant EXTRA: constant Regexp.PCRE.OPTION.EXTRA
Description: (from the pcreapi manpage) This option was invented in order to turn on additional functionality of PCRE that is incompatible with Perl, but it is currently of very little use. When set, any backslash in a pattern that is followed by a letter that has no special meaning causes an error, thus reserving these combinations for future expansion. By default, as in Perl, a backslash followed by a letter with no special meaning is treated as a literal. There are at present no other features controlled by this option. It can also be set by a (?X) option setting within a pattern.

Constant MULTILINE

constant Regexp.PCRE.OPTION.MULTILINE

Description

(from the pcreapi manpage) By default, PCRE treats the subject string as consisting of a single "line" of characters (even if it actually contains several newlines). The "start of line" metacharacter (^) matches only at the start of the string, while the "end of line" metacharacter ($) matches only at the end of the string, or before a terminating newline (unless PCRE_DOL- LAR_ENDONLY is set). This is the same as Perl.

When PCRE_MULTILINE it is set, the "start of line" and "end of line" constructs match immediately following or immediately before any new- line in the subject string, respectively, as well as at the very start and end. This is equivalent to Perl's /m option, and it can be changed within a pattern by a (?m) option setting. If there are no "\n" charac- ters in a subject string, or no occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect.

Constant NO_AUTO_CAPTURE: constant Regexp.PCRE.OPTION.NO_AUTO_CAPTURE
Description: (from the pcreapi manpage) If this option is set, it disables the use of numbered capturing paren- theses in the pattern. Any opening parenthesis that is not followed by ? behaves as if it were followed by ?: but named parentheses can still be used for capturing (and they acquire numbers in the usual way). There is no equivalent of this option in Perl.

Constant UNGREEDY: constant Regexp.PCRE.OPTION.UNGREEDY
Description: (from the pcreapi manpage) This option inverts the "greediness" of the quantifiers so that they are not greedy by default, but become greedy if followed by "?". It is not compatible with Perl. It can also be set by a (?U) option setting within the pattern.

Constant UTF8: constant Regexp.PCRE.OPTION.UTF8
Description: (from the pcreapi manpage) This option causes PCRE to regard both the pattern and the subject as strings of UTF-8 characters instead of single-byte character strings. However, it is available only if PCRE has been built to include UTF-8 support. If not, the use of this option provokes an error. Details of how this option changes the behaviour of PCRE are given in the section on UTF-8 support in the main pcre page.