Regular expressions in Tosca

A regular expression is a character string that consists of characters and metacharacters. You can use regular expressions to find character patterns in a text. For instance, regular expressions can help you find data that can be expressed in different formats, such as: Dates (e.g. mm/dd/yy, dd-mm-yyyy).

Tosca TBox supports regular expressions, which are used to compare whether the target attribute contains a string that matches the regular expression. The regular expression must be specified within double quotation marks.

Syntax:

{REGEX["regular expression"]}

A leading escape character is required in order to allow quotation marks to be used accordingly in the regular expression.

Metacharacters:  Metacharacters are characters with a special meaning. You can use the following metacharacters in regular expressions.

[ ] -Finds every character in the square brackets. we can group several characters.

Ex - 

[abc] matches a, b or c.

[a-z] defines the range of lowercase letters from a to z.

[^] - Finds every character that is not in the square brackets. We can group characters and use ranges.

Ex - 

[^abc] matches every character except a, b or c.

[^a-z] matches every character except lowercase letters from a to z.

. - Matches any single character except for a line or paragraph break.

Ex -  a.c matches abc, aTc, a$c, a c etc.

\d  - Finds numeric characters.

Ex -  \d\d\d matches any three digit number, e.g. 145, 238 etc.

\w - Finds alphanumeric characters.

Ex - \w matches a, b, c, d, e, f in abc def.

+ - Specifies that the preceding element appears one or more times.

Ex - ab+c matches abc, abbc, abbbc etc.

? - Specifies that the preceding element appears once or not at all.

Ex - ab?c matches ac or abc.

* - Specifies that the preceding element appears zero or more times.

Ex- ab*c matches ac, abc, abbc etc.

{n} - Specifies that the preceding element appears exactly n times.

Ex- ab{3}c matches abbbc.

{n,m} - Specifies that the preceding element can appear at least n times but not more than m times.

Ex- ab{2,4}c matches abbc, abbbc and abbbbc.

\b - Finds a word boundary.

Ex - \b\d\d\w+ matches a character string that begins with two numbers and continues with one or more alphanumeric characters, e.g. 12He(\t34aq.

( ) - Defines sub-expressions.

Ex - (\d\d\d\s)+ matches sequences of three-digit numbers, e.g. 123 456 789 012.

| - Finds either the preceding or following element.

Ex - (ab)|(cd) matches ab or cd.

\ - Specifies if the following character has a literal or special meaning.

Ex - \+ indicates the plus sign, + is a metacharacter.

\d is a metacharacter, d indicates the respective letter of the alphabet.

^ - Indicates the beginning of a line.

Ex - ^The matches any string that begins with The.

$ - Indicates the end of a line.

Ex - $end matches any string that ends with end.

\s - Finds whitespace characters.

Ex - \s* matches zero or more whitespace characters.

i - Uses case-insensitive matching.

Ex - (?i)test ignores upper-case and lower-case to find a match, e.g. test, Test, TEST, teST etc.