A convenience function to tune the ICU regular expressions
matcher's behavior, e.g., in stri_count_regex
and other stringi-search-regex functions.
stri_opts_regex(
case_insensitive,
comments,
dotall,
dot_all = dotall,
literal,
multiline,
multi_line = multiline,
unix_lines,
uword,
error_on_unknown_escapes,
time_limit = 0L,
stack_limit = 0L,
...
)logical; enables case insensitive matching [regex flag (?i)]
logical; allows white space and comments within patterns [regex flag (?x)]
logical; if set, `.` matches line terminators,
otherwise matching of `.` stops at a line end [regex flag (?s)]
alias of dotall
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-search-fixed facilities in this case
logical; controls the behavior of `$` and `^`.
If set, recognize line terminators within a string, otherwise,
match only at start and end of input string [regex flag (?m)]
alias of multiline
logical; Unix-only line endings;
when enabled, only U+000a is recognized as a
line ending by `.`, `$`, and `^`.
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. [regex flag (?w)]
See https://unicode.org/reports/tr29/#Word_Boundaries
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
integer; processing time limit, in ~milliseconds (but not precisely so, depends on the CPU speed), for match operations; setting a limit is desirable if poorly written regexes are expected on input; 0 for no limit
integer; maximal size, in bytes, of the heap storage available for the match backtracking stack; setting a limit is desirable if poorly written regexes are expected on input; 0 for no limit
[DEPRECATED] any other arguments passed to this function generate a warning; this argument will be removed in the future
Returns a named list object; missing settings are left with default values.
Note that some regex settings may be changed using ICU regex flags
inside regexes. For example, '(?i)pattern' performs
a case-insensitive match of a given pattern,
see the ICU User Guide entry on Regular Expressions
in the References section or stringi-search-regex.
enum URegexpFlag: Constants for Regular Expression Match Modes
-- ICU4C API Documentation,
https://unicode-org.github.io/icu-docs/apidoc/dev/icu4c/uregex_8h.html
Regular Expressions -- ICU User Guide, http://userguide.icu-project.org/strings/regexp
Other search_regex:
about_search_regex,
about_search
# NOT RUN {
stri_detect_regex('ala', 'ALA') # case-sensitive by default
stri_detect_regex('ala', 'ALA', opts_regex=stri_opts_regex(case_insensitive=TRUE))
stri_detect_regex('ala', 'ALA', case_insensitive=TRUE) # equivalent
stri_detect_regex('ala', '(?i)ALA') # equivalent
# }
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