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Function "Matches"
Matches(text, regexp)
Function: Checks if "text" matches the regular expression in "regexp". Returns "true" if the text matches, "false" if not.
A regular expression, which can be seen as a "pattern", is an expression that describes a set of texts. With this expression, the desired set can be described without having to list all elements. Therefore, the "Matches" function actually does nothing else than to check whether the given "text" is among the set of texts that is defined by the regular expression in "regexp".
To be able to describe a whole set of texts with a single expression, regular expressions make intensive use of special character constructs, such as wildcards, quantifiers, boundary matchers, and others. The topic of regular expressions is a very wide field. For more details, please see the available literature.
For the regular expression constructs that are supported by LISTSERV Maestro, please see below.
Return-Type: Boolean
Arguments:
text - Type Text: The text string to match.
regexp - Type Text: The regular expression to use.
Examples:
Matches("a longer text", "longer")
Matches(&VALUE;, "sample")
Regular Expression Constructs Supported by Maestro
Note: Maestro's evaluation of regular expression is based on the regular expression implementation of the Java class library. For details about escaping, quoting, character classes, line terminators, groups, capturing, Unicode support, a comparision to Perl-5 and other in-depth information, please see the Java documentation.
| Construct | Matches |
|---|---|
| Characters | |
| x | The character x |
| \\ | The backslash character |
| \0n | The character with octal value 0n (0 <= n <= 7) |
| \0nn | The character with octal value 0nn (0 <= n <= 7) |
| \0mnn | The character with octal value 0mnn (0 <= m <= 3, 0 <= n <= 7) |
| \xhh | The character with hexadecimal value 0xhh |
| \uhhhh | The character with hexadecimal value 0xhhhh |
| \t | The tab character ('\u0009') |
| \n | The newline (line feed) character ('\u000A') |
| \r | The carriage-return character ('\u000D') |
| \f | The form-feed character ('\u000C') |
| \a | The alert (bell) character ('\u0007') |
| \e | The escape character ('\u001B') |
| \cx | The control character corresponding to x |
| Character classes | |
| [abc] | a, b, or c (simple class) |
| [^abc] | Any character except a, b, or c (negation) |
| [a-zA-Z] | a through z or A through Z, inclusive (range) |
| [a-d[m-p]] | a through d, or m through p: [a-dm-p] (union) |
| [a-z&&[def]] | d, e, or f (intersection) |
| [a-z&&[^bc]] | a through z, except for b and c: [ad-z] (subtraction) |
| [a-z&&[^m-p]] | a through z, and not m through p: [a-lq-z](subtraction) |
| Predefined character classes | |
| . | Any character (may or may not match line terminators) |
| \d | A digit: [0-9] |
| \D | A non-digit: [^0-9] |
| \s | A whitespace character: [ \t\n\x0B\f\r] |
| \S | A non-whitespace character: [^\s] |
| \w | A word character: [a-zA-Z_0-9] |
| \W | A non-word character: [^\w] |
| POSIX character classes (US-ASCII only) | |
| \p{Lower} | A lower-case alphabetic character: [a-z] |
| \p{Upper} | An upper-case alphabetic character:[A-Z] |
| \p{ASCII} | All ASCII:[\x00-\x7F] |
| \p{Alpha} | An alphabetic character:[\p{Lower}\p{Upper}] |
| \p{Digit} | A decimal digit: [0-9] |
| \p{Alnum} | An alphanumeric character:[\p{Alpha}\p{Digit}] |
| \p{Punct} | Punctuation: One of !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~ |
| \p{Graph} | A visible character: [\p{Alnum}\p{Punct}] |
| \p{Print} | A printable character: [\p{Graph}\x20] |
| \p{Blank} | A space or a tab: [ \t] |
| \p{Cntrl} | A control character: [\x00-\x1F\x7F] |
| \p{XDigit} | A hexadecimal digit: [0-9a-fA-F] |
| \p{Space} | A whitespace character: [ \t\n\x0B\f\r] |
| java.lang.Character classes | |
| \p{javaLowerCase} | Equivalent to java.lang.Character.isLowerCase() |
| \p{javaUpperCase} | Equivalent to java.lang.Character.isUpperCase() |
| \p{javaWhitespace} | Equivalent to java.lang.Character.isWhitespace() |
| \p{javaMirrored} | Equivalent to java.lang.Character.isMirrored() |
| Classes for Unicode blocks and categories | |
| \p{InGreek} | A character in the Greek block (simple block) |
| \p{Lu} | An uppercase letter (simple category) |
| \p{Sc} | A currency symbol |
| \P{InGreek} | Any character except one in the Greek block (negation) |
| [\p{L}&&[^\p{Lu}]] | Any letter except an uppercase letter (subtraction) |
| Boundary matchers | |
| ^ | The beginning of a line |
| $ | The end of a line |
| \b | A word boundary |
| \B | A non-word boundary |
| \A | The beginning of the input |
| \G | The end of the previous match |
| \Z | The end of the input but for the final terminator, if any |
| \z | The end of the input |
| Greedy quantifiers | |
| X? | X, once or not at all |
| X* | X, zero or more times |
| X+ | X, one or more times |
| X{n} | X, exactly n times |
| X{n,} | X, at least n times |
| X{n,m} | X, at least n but not more than m times |
| Reluctant quantifiers | |
| X?? | X, once or not at all |
| X*? | X, zero or more times |
| X+? | X, one or more times |
| X{n}? | X, exactly n times |
| X{n,}? | X, at least n times |
| X{n,m}? | X, at least n but not more than m times |
| Possessive quantifiers | |
| X?+ | X, once or not at all |
| X*+ | X, zero or more times |
| X++ | X, one or more times |
| X{n}+ | X, exactly n times |
| X{n,}+ | X, at least n times |
| X{n,m}+ | X, at least n but not more than m times |
| Logical operators | |
| XY | X followed by Y |
| X|Y | Either X or Y |
| (X) | X, as a capturing group |
| Back references | |
| \n | Whatever the nth capturing group matched |
| Quotation | |
| \ | Nothing, but quotes the following character |
| \Q | Nothing, but quotes all characters until \E |
| \E | Nothing, but ends quoting started by \Q |
| Special constructs (non-capturing) | |
| (?:X) | X, as a non-capturing group |
| (?idmsux-idmsux) | Nothing, but turns match flags on - off |
| (?idmsux-idmsux:X) | X, as a non-capturing group with the given flags on - off |
| (?=X) | X, via zero-width positive lookahead |
| (?!X) | X, via zero-width negative lookahead |
| (?<=X) | X, via zero-width positive lookbehind |
| (?<!X) | X, via zero-width negative lookbehind |
| (?>X) | X, as an independent, non-capturing group |