Paggern
Pattern interpreter for generating random strings.
Generator
$generator = new \Gajus\Paggern\Generator();
/**
* Generate a set of random codes based on Paggern pattern.
* Codes are guaranteed to be unique within the set.
*
* @param string $pattern Paggern pattern.
* @param int $amount Number of codes to generate.
* @param int $safeguard Number of additional codes generated in case there are duplicates that need to be replaced.
* @return array
*/
$codes = $generator->generateFromPattern('FOO[A-Z]{10}[0-9]{2}', 100);
The above example will generate an array containing 100 codes, each prefixed with "FOO", followed by 10 characters from "ABCDEFGHKMNOPRSTUVWXYZ23456789" haystack and 2 numbers from "0123456789" haystack.
Paggern utilises RandomLib to generate the pattern matching random character pool.
Lexer
Lexer exposes a method to tokenise the string. Lexer
is independant of the Generator
. You can choose to interpret Lexer
tokens using your own implementation of the Generator
.
$lexer = new \Gajus\Paggern\Lexer();
/**
* Tokeniser explodes input into components describing the properties expressed in the pattern.
*
* @param string $pattern
* @param boolean $expand Augment token definition with the haystack of possible values.
* @return array
*/
$lexer->tokenise('[a-c]{3}[1-3]{3}', true);
[
[
'type' => 'range',
'token' => 'a-c',
'repetition' => 3,
'haystack' => 'abc'
],
[
'type' => 'range',
'token' => '1-3',
'repetition' => 3,
'haystack' => 123
]
]
Supported Tokens
Literal
Pattern can consist of literal characters, e.g. prefix of suffix of the code.
$lexer->tokenise('abc');
[
[
'type' => 'literal',
'string' => 'abc'
]
]
The above pattern commands that the string is literally "abc".
Range
Range can be either numeric or ASCII.
$lexer->tokenise('[a-z]');
In the [a-z]
example, string must be a character from "abcdefghijklmnopqrstuvwxyz" haystack.
[
[
'type' => 'range',
'token' => 'a-z',
'repetition' => 1
]
]
Range with Repetition
If the character must occur more than once, use repetition.
$lexer->tokenise('[a-c]{3}');
In the [a-z]{3}
example, string must consist of 3 characters from the "abc" haystack.
[
[
'type' => 'range',
'token' => 'a-c',
'repetition' => 3
]
]
Character Classes
Predefined character classes can be used instead of ranges.
Character Class | Range |
---|---|
\U |
"ABCDEFGHKMNOPRSTUVWXYZ23456789" (or A-Z0-9 excluding IJLQ01) describes characters that are unambiguously recognised regardless of the font or case-sensitivity. The designated use case is voucher codes. |
Character Classes with Repetition
Similar to the Range with Repetition, Character Classes can be used with repetition, e.g.
$lexer->tokenise('\U{3}');
Limitations
- Pattern cannot include
[]{}
characters. - Pattern cannot include characters outside of the ASCII.