stringi (version 0.2-4)

stri_opts_regex: Generate a List with Regex Matcher Settings

Description

A convenience function to tune the ICU regular expressions matcher's behavior, e.g. in stri_count_regex and other stringi-search-regex functions.

Usage

stri_opts_regex(case_insensitive, comments, dotall, literal, multiline,
  unix_lines, uword, error_on_unknown_escapes)

Arguments

case_insensitive

logical; enable case insensitive matching

comments

logical; allow white space and comments within patterns

dotall

logical; if set, `.` matches line terminators, otherwise matching of `.` stops at a line end

literal

logical; if set, treat the entire pattern as a literal string: metacharacters or escape sequences in the input sequence will be given no special meaning; note that in most cases you would rather use the stringi

multiline

logical; controls the behavior of `$` and `^`. If set, recognize line terminators within a string, otherwise, match only at start and end of input string

unix_lines

logical; Unix-only line endings. When this mode is enabled, only U+000a is recognized as a line ending by `.`, `$`, and `^`.

uword

logical; Unicode word boundaries. If set, uses the Unicode TR 29 definition of word boundaries; warning: Unicode word boundaries are quite different from traditional regex word boundaries. See http://unicode.org/reports/tr29/#Word_Boundaries

error_on_unknown_escapes

logical; whether to generate an error on unrecognized backslash escapes; if set, fail with an error on patterns that contain backslash-escaped ASCII letters without a known special meaning; otherwise, these escaped letters represent themselves.

Note that

Value

• Returns a named list object; missing settings are left with default values.

References

enum URegexpFlag: Constants for Regular Expression Match Modes -- ICU4C API Documentation, http://www.icu-project.org/apiref/icu4c/uregex_8h.html

Regular Expressions -- ICU User Guide, http://userguide.icu-project.org/strings/regexp

See Also

Other search_regex: stri_count_regex; stri_detect_regex; stri_extract_all_regex, stri_extract_first_regex, stri_extract_first_regex, stri_extract_last_regex, stri_extract_last_regex; stri_locate_all_regex, stri_locate_first_regex, stri_locate_first_regex, stri_locate_last_regex, stri_locate_last_regex; stri_match_all_regex, stri_match_first_regex, stri_match_first_regex, stri_match_last_regex, stri_match_last_regex; stri_replace_all_regex, stri_replace_first_regex, stri_replace_first_regex, stri_replace_last_regex, stri_replace_last_regex; stri_split_regex; stringi-search-regex; stringi-search

Examples

stri_detect_regex("ala", "ALA") # case-sensitive by default
stri_detect_regex("ala", "ALA", stri_opts_regex(case_insensitive=TRUE))
stri_detect_regex("ala", "(?i:)ALA") # equivalent