wildling

Swift library and CLI for pattern-based string generation. Zero third-party packages (Foundation / Swift standard library only). Targets Swift 5.9+ / 6.x on Linux or macOS.

Docs: Website · Sandbox · Syntax · Source

Registry: Swift Package Index · Git (SwiftPM)

Example

http://${'dev,stage,prod'}\-${'api,web'}#{0-2}.example.${'com,net,org'}/@.html

(The \- is a literal hyphen; bare - would mean “one letter or digit”. @ is one lowercase letter.)

That builds URL-shaped candidates: scheme http://, then environment × service × optional digits × TLD, then a one-letter path page. Three environments, two services, zero–two digits ('', 0–9, 00–99), three TLDs, and a–z → 51948 strings — the kind of list you generate for fuzzing links or probing staging hosts, not type out.

A few of them:

http://dev-api.example.com/a.html / http://stage-web.example.com/z.html
http://dev-api0.example.net/a.html / http://prod-web9.example.org/m.html
http://dev-api00.example.com/a.html / http://prod-web99.example.org/z.html

Named dictionaries (%{'hosts'}) work the same way when the word lists live in files.

Try it in the sandbox, or see pattern syntax for length ranges, dictionaries, and escapes.

Install

From this repository:

cd swift
./build.sh
./bin/wildling "Year 19##"

SwiftPM (dotmonk/wildling-swift):

dependencies: [
    .package(url: "https://github.com/dotmonk/wildling-swift.git", from: "2.0.0"),
],
targets: [
    .target(name: "MyApp", dependencies: [
        .product(name: "Wildling", package: "wildling"),
    ]),
]

import Wildling

let wildling = Wildling(patterns: ["Year 19##"])
while let value = wildling.next() {
    print(value)
}

CLI

./bin/wildling "Year 19##"
./bin/wildling --dictionary planets:../dictionaries/planets.txt "%{'planets'}"
./bin/wildling --template ./config.json

Help text and --check output follow docs/cli.md / docs/help.txt.

Build

./build.sh   # Docker (swift:6.0-bookworm): swiftc -static-stdlib → dist/wildling

Project tests live in ../tests/ and are run with ../test.sh.