wildling

F# library and CLI for pattern-based string generation. Zero NuGet dependencies (.NET BCL only). Targets .NET 8.

Docs: Website · Sandbox · Syntax · Source

Registry: NuGet

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 fsharp
./build.sh
./bin/wildling "Year 19##"

From a release tag:

git clone --branch v2.0.7 --depth 1 https://github.com/dotmonk/wildling.git
cd wildling
./build.sh fsharp

Registry (CLI): NuGet package DotMonk.Wildling.FSharp is a .NET tool (PackAsTool), not a library PackageReference:

dotnet tool install -g DotMonk.Wildling.FSharp
wildling-fs "Year 19##"

Library: reference the project from a clone (or the built dist/ assembly).

open WildlingLib

let wildling = Wildling.Create([ "Year 19##" ])
let mutable value = wildling.Next()
while not (match value with :? bool as b -> b = false | _ -> false) do
    printfn "%O" value
    value <- wildling.Next()

Produces dist/wildling.dll when built from this tree. Requires the .NET 8 runtime, or Docker (the launcher falls back to the runtime image if dotnet is not on PATH).

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 (dotnet SDK 8): publish to dist/, copies help.txt

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