regen (package)

This is a fork of nilium/regen transformed into a golang package.

Usage

$ go get github.com/kekersdev/regen

Examples

Simple

package main

import (
    "fmt"

    "github.com/kekersdev/regen"
)

func main() {
    xeger := regen.FromPattern(`0x[\da-f]{16}`)
    fmt.Println(xeger.MustGenerate())
}

FromPattern() accepts a regular expression as a single parameter, parses it assuming it uses Perl-like syntax and returns a ready-to-use instance of string generator or nil in case of an error.

MustGenerate() method returns a new generated string. Will panic if an error occurs during generation.

Advanced

package main

import (
    "fmt"
    "regexp/syntax"

    "github.com/kekersdev/regen"
)

func main() {
    xeger := &XegerGenerator

    xeger.AddPattern(`0x[\da-f]{16}`,     syntax.Perl,  false)
    xeger.AddPattern(`#[[:alpha:]]{5,6}`, syntax.POSIX, true)

    xeger.SetUnboundLimit(10)

    if str, err := xeger.Generate(); err != nil {
        fmt.Println("Failed to generate string")
    } else {
        fmt.Println(str)
    }
}

AddPattern() method offers more flexibility as it allows to specify expression parser flags and wether or not parsed expression should be simplified. Note: when a generator instance holds multiple expressions, a random one will be selected when generating a string.

SetUnboundLimit() method allows to change the default maximum number of repetitions for patterns with unbound quantifiers (+/*). Note: default limit for repetitions is 32, the same as for the original regen.

Generate() method works the same as MustGenerate() but returns an error alongside the generated string. If an error occurs during generation the returned string will be empty. Note: while the original regen may panic in certain situations, Generate() will return an error instead.

License

regen is licensed under a 2-clause BSD license. This can be found in LICENSE.txt.