# alias Regex::CompileOptions

##
Overview

Represents compile options passed to `Regex.new`.

This alias is supposed to replace `Options`.

##
Alias Definition

`Regex::Options`

##
Defined in:

regex.cr

##
Constant Summary

All = `6980118591_u64`
ANCHORED = `16_u64`

  Force pattern anchoring at the start of the subject.

DOLLAR_ENDONLY = `32_u64`
DOTALL = `2_u64`
ENDANCHORED = `2147483648_u64`

  Force pattern anchoring at the end of the subject.

  Unsupported with PCRE.

EXTENDED = `8_u64`

  Ignore white space and `#` comments.

FIRSTLINE = `262144_u64`
IGNORE_CASE = `1_u64`

  Case insensitive match.

MATCH_INVALID_UTF = `4294967296_u64`

  Enable matching against subjects containing invalid UTF bytes. Invalid bytes never match anything. The entire subject string is effectively split into segments of valid UTF.

  Read more in the PCRE2 documentation.

  When this option is set, `MatchOptions::NO_UTF_CHECK` is ignored at match time.

  Unsupported with PCRE.

  NOTE This option was introduced in PCRE2 10.34 but a bug that can lead to an infinite loop is only fixed in 10.36 (https://github.com/PCRE2Project/pcre2/commit/e0c6029a62db9c2161941ecdf459205382d4d379).

MULTILINE = `6_u64`

  Multiline matching.

  Equivalent to `MULTILINE | DOTALL` in PCRE and PCRE2.

NO_UTF_CHECK = `8192_u64`

  Do not check the pattern for valid UTF encoding.

  This option is potentially dangerous and must only be used when the pattern is guaranteed to be valid (e.g. `String#valid_encoding?`). Failing to do so can lead to undefined behaviour in the regex library and may crash the entire process.

  NOTE `String` is supposed to be valid UTF-8, but this is not guaranteed or enforced. Especially data originating from external sources should not be trusted.

  UTF validation is comparatively expensive, so skipping it can produce a significant performance improvement.

      pattern = "fo+"
      if pattern.valid_encoding?
        regex = Regex.new(pattern, options: Regex::CompileOptions::NO_UTF_CHECK)
        regex.match(foo)
      else
        raise "Invalid UTF in regex pattern"
      end

  The standard library implicitly applies this option when it can be sure about the patterns's validity (e.g. on repeated matches in `String#gsub`).

None = `0_u64`