REGEXP – Regular expression parser

Block SymbolLicensing group: ADVANCED

Function Description
The REGEXP block implements the most common subset of regular expressions as known, for example, from the regex command in Perl or C#, or the grep command known from the command line of Unix operating systems.

Supported syntax is as follows:

(?i) …Must be at the beginning of the regex. Makes match case-insensitive
^ …Match beginning of a buffer
$ …Match end of a buffer
() …Grouping and substring capturing
\s …Match whitespace
\S …Match non-whitespace
\d …Match decimal digit
\n …Match new line character
\r …Match line feed character
\f …Match form feed character
\v …Match vertical tab character
\t …Match horizontal tab character
\b …Match backspace character
+ …Match one or more times (greedy)
+? …Match one or more times (non-greedy)
* …Match zero or more times (greedy)
*? …Match zero or more times (non-greedy)
? …Match zero or once (non-greedy)
x|y …Match x or y (alternation operator)
\meta …Match one of the meta characters: ^$().[ ]*+?|\
\xHH …Match byte with hex value 0xHH, e.g. \x4a
[...] …Match any character from set. Ranges like [a-z] are supported.
[^...]…Match any character except the ones in set. Ranges like [a-z] are supported.

Examples

[0-9]+ …Finds first integer in input string (and puts it into cap output).
[-+]?[0-9]*\.[0-9]+([eE][-+]?[0-9]+)?…Find first real number in input string (and puts it into cap output).
^\s*(.*?)\s*$ …Puts trimmed input string into cap1 output.
num\s*:\s*([0-9]*\.[0-9]*) …Expects input string in JSON format; find integer parameter num, and puts its value into cap1.

This block does not propagate the signal quality. More information can be found in the 1.4 section.

Input

text	String to parse	String
RUN	Enable execution	Bool

Parameter

expr	Regular expression pattern	String
nmax	Allocated size of string $↓$ 0 $↑$ 65534	Long (I32)
bufmax	Parser internal buffer size (0 = autodetect) $↓$ 0 $↑$ 10000000	Long (I32)

Output

MATCH	Pattern match flag	Bool
cap	Whole matching string	String
cap1..cap8	Captured string	String

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