---json
{
    "page_id": "v8oxynmmjrs2dhkvt6n8f"
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---
====== Regular Expression Generator ======


===== About =====
''regexp'' is a [[:docs:generator:data-supplier|data supplier]] that generates data based on a regular expression.

===== Example =====

  * [[:howto:generator:regexp_number]]

===== Example =====

Generation of a decimal that has:
  * 3 digits in the integral part
  * 3 digits in the fractional part
thanks to the regular expression ''%%[0-9]{3}\.[0-9]{3}%%''

<file yml generator/regexp--generator.yml>
columns:
  - name: regexp_double
    type: Double
    precision: 6
    scale: 3
    data-supplier:
      type: regexp
      arguments:
        expression: '[0-9]{3}\.[0-9]{3}'
        # an optional seed to get deterministic value between execution
        seed: 1234L
</file>


===== Arguments =====

==== Expression ====

''expression'' is a [[kb>lang:regexp:regexp|regular expression]] that defines the pattern of the data that should be generated.

The following table shows the supported syntax:

^                        Pattern ^ Description  ^
|                            `.` | Any symbol. See below details - `Dot pattern generated symbols` section.                                                             |
|                            `?` | One or zero occurrences                                                                                                              |
|                            `+` | One or more occurrences                                                                                                              |
|                            `*` | Zero or more occurrences                                                                                                             |
|                           `\r` | Carriage return `CR` character                                                                                                       |
|                           `\t` | Tab `	` character                                                                                                                    |
|                           `\n` | Line feed `LF` character.                                                                                                            |
|                           `\d` | A digit. Equivalent to `[0-9]`                                                                                                       |
|                           `\D` | Not a digit. Equivalent to `[^0-9]`                                                                                                  |
|                           `\s` | Configurable. By default: Space or Tab. See `WHITESPACE_DEFINITION` property.                                                        |
|                           `\S` | Anything, but Carriage Return, Space, Tab, Newline, Vertical Tab, Form Feed                                                          |
|                           `\w` | Any word character. Equivalent to `[a-zA-Z0-9_]`                                                                                     |
|                           `\W` | Anything but a word character. Equivalent to `[^a-zA-Z0-9_]`                                                                         |
|                           `\i` | Places same value as capture group with index `i`. `i` is any integer number.                                                        |
|                  `\Q` and `\E` | Any characters between `\Q` and `\E`, including metacharacters, will be treated as literals.                                         |
|                  `\b` and `\B` | These characters are ignored. No validation is performed!                                                                            |
|          `\xXX` and `\x{XXXX}` | Hexadecimal value of unicode characters 2 or 4 hexadecimal digits                                                                    |
|                       `\uXXXX` | Hexadecimal value of unicode characters 4 hexadecimal digits                                                                         |
|                      `\p{...}` | Any character in class. See details below before use.                                                                                |
|                      `\P{...}` | Any character not in class. See details below before use.                                                                            |
|              `{a}` and `{a,b}` | Repeat a; or min a max b times. Use {n,} to repeat at least n times.                                                                 |
|                        `[...]` | Single character from ones that are inside brackets. `[a-zA-Z]` (dash) also supported                                                |
|                       `[^...]` | Single character except the ones in brackets. `[^a]` - any symbol except 'a'                                                         |
|                           `()` | To group multiple characters for the repetitions                                                                                     |
|                             %%\\%% | Escape character (use %%\\\\%% (double backslash) to generate single %\% character)                                                        |

==== Seed ====

''seed'' is optional. It's a [[kb>seed|start point in the generation of pseudo-random numbers]].

If set the data will be deterministic between executions.
===== Limitations =====

Limitations and syntax information can be found on the [[https://github.com/curious-odd-man/RgxGen|RxGen Library]]