wildling

TypeScript library and CLI for pattern-based string generation. Runtime has zero npm dependencies (Node.js only); TypeScript is a build-time devDependency.

Docs: Website · Sandbox · Syntax · Source

Registry: npm

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

Registry:

npm install wildling

Git (monorepo subdirectory):

npm install "git+https://github.com/dotmonk/wildling.git#v2.0.0:javascript"

prepare builds dist/ when missing (Node 18+, network for TypeScript on first install).

In package.json:

"wildling": "github:dotmonk/wildling#v2.0.0:javascript"

From this repository:

cd javascript
npm ci --include=dev
npm run build

The CLI is ./bin/wildling. The library entry is dist/index.js.

Library

const createWildling = require("wildling").default;
// or: import createWildling from "wildling";

const wildling = createWildling({
  patterns: ["abrakadabra", "Year 19##"],
  dictionaries: {
    colors: ["red", "blue"],
  },
});

wildling.count(); // 101
wildling.get(0); // "abrakadabra"

let value;
while ((value = wildling.next())) {
  console.log(value);
}

wildling.reset();

Options

Field	Type	Description
`patterns`	`string[]`	One or more patterns to expand
`dictionaries`	`{ [name: string]: string[] }`	Named word lists for `%{'name'}`

API

Method	Description
`next()`	Next combination, or `false` when exhausted
`get(index)`	Combination at `index`, or `false` if out of range
`count()`	Total combinations across all patterns
`index()`	Current position (after `next` calls)
`reset()`	Reset iteration to the start
`generators()`	Per-pattern generators

CLI

wildling [options] [pattern ...]

Option	Description
`--select #`	Print only combination `#` (repeatable)
`--range #-#`	Print combinations from `#` to `#` inclusive (repeatable)
`--check`	Print generation info instead of results
`--dictionary <name>:<path>`	Load a dictionary file as `<name>` (repeatable)
`--template <path>`	Load options from a JSON template
`--help`, `-h`	Help (shared text from `docs/help.txt`)
`--version`, `-v`	Version

--check and help text follow the cross-language contracts in docs/cli.md.

Examples:

./bin/wildling "Year 19##"
./bin/wildling --dictionary planets:../dictionaries/planets.txt "%{'planets'}"
./bin/wildling --select 0 --range 8-9 "##"
./bin/wildling --template ./config.json

Template JSON

{
  "patterns": ["Year 19##", "%{'colors'}"],
  "dictionaries": {
    "colors": "path/to/colors.txt",
    "inline": ["red", "blue"]
  },
  "select": [0, 2],
  "range": ["5-7"],
  "check": false
}

Dictionary values may be a file path or an inline string array. Template fields merge with CLI flags in argument order.

Patterns

Simple wildcards

Token	Alphabet
`#`	`0-9`
`@`	`a-z`
`*`	`a-z` and `0-9`
`&`	`a-zA-Z`
`!`	`A-Z`
`?`	`A-Z` and `0-9`
`-`	`a-zA-Z0-9`

Optional length: #{2}, @{1-2}, *{1-2} (start–end inclusive).

Special wildcards

${'blue,red,green',1-2}   words / punctuation from a list
%{'colors'}               dictionary named "colors"
%{'colors',1-2}           dictionary with length range

Escape a wildcard with a backslash: \## → #0 … #9.

Build

npm run build
# or from repo root: ./build.sh  (Docker)

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