The Javascript powered, pluggable Muschcode engine.

• Installation
• Basic Usage
  • string(lists: string, ctx: Context) => Promise<string>
  • Functions
    • add(name: string, (args: string[], data = {}) => {})
  • Substitutions
    • addSubs(list: string, ...subs: Sub[])
    • substitute(lists: string, msg: string)
• Plugins
• Development

Installation

install the parser with your favorite package manager:

npm install @ursamu/parser
yarn add @ursamu/parser

Basic Usage

import { Parser } from "@ursamu/parser";

// Create a new parser.
const parser = new Parser();

// add a function
parser.add("div", (args) => parseInt(args[0]) / parseInt(args[1]));

// Add some substitutions
parser.addSub(
  "telnet",
  { before: /%r/g, after: "\n" },
  { before: /%b/g, after: " " },
  { before: /%t/g, after: "\t" }
);

// run the parser!
parser
  .string("telnet", {
    msg: "Hello %0!! [div(6,2)]",
    scope: { "%0": "World!" },
    data: {},
  })
  .then((results) => console.log(results)); // => Hello World!!! 3

string(lists: string, ctx: Context) => Promise<string>

Functions

Functions are the basis of mushcode, and through the parser you are able to represent whatever codebase you wish!

add(name: string, (args: string[], data = {}) => {})

Add a new function to the parser.

parser.add("hello", (args) => `hello ${args[0]}!`);
// hello(Dave) => hello Dave!

parser.add("add", (args) => args.reduce((a, b) => a + parseInt(b), 0));
// add(2,3) => 5

• args The following args are available to the add method:
  • args: any[] An array of arguments given the function in a comma seperated list.
  • data: {} An object where any data needed by the run of the parser is kept. enactor, target, location, etc.

Substitutions

The parser comes with a customisable substitution system that can take stand in expressions. In a Mux-like example %crWARNING!!%cn. To customize what substitutisns are available through the parser:

addSubs(list: string, ...subs: Sub[])

Add a new subsitution to the parser. There are two lists that are pre-determined. pre and post. pre substitutions happen before the code is run through the eval process. post happens after all of the other substitutions have been run.

• list is the list of substitutions that this range should be added too.
• subs A comma seperated list of substitutions to be added to the particular label.
  • before The starting string or regular expression to search for.
  • after What the matched regular expression or text should be substituted for. If you've ised a regi;ar expression for your before, then you can use wildcard matches $1.
  • strip? When a function strips the substitutions from your string, what characters should it be substituted with? With most you can get away with a space, or leaving the field blank.

parser.addSubs("telnet", [
  {
    before: /%r/g,
    after: "\n",
  }.
  {
    before: /%t/g,
    after: "\t",
    strip: "    "
  }
]);

substitute(lists: string, msg: string)

Make substitutions from the provided apace seperated list string omto the message.

const results = parser.substitute("telnet", "This is a %rtest.");

Plugins

The parser is customizable through a rogbust plugin system.

parser.plugin(myPlugin)

The syntax for creating a plugin is simple:

export const plugin = (parser) => {
  parser.add("add", (args) => args.reduce((a, b) => a + b, 0));
};

Development