greyscript-core

A lexer and parser that extends greybel-core with Grey Hack-specific language features. GreyScript is the scripting language used inside Grey Hack and is a superset of both MiniScript and Greybel.

Features on top of greybel-core

import_code

Grey Hack's native mechanism for importing compiled scripts at runtime:

import_code("mylib.src")

The parser produces an ASTImportCodeExpression node with the following properties:

| Property | Description | |---|---| | directory | The resolved import path | | originalDirectory | The path as written in source | | eval | Whether the import should be evaluated (default true) | | emit | Whether the import should be emitted (default true) |

Meta options can be attached via semicolon-delimited tags in the path string (e.g. no-eval, no-emit, override=<path>).

Full feature stack

greyscript-core inherits all features from the packages it extends:

| Layer | Key additions | |---|---| | miniscript-core | Base MiniScript lexer, parser, AST, error recovery | | greybel-core | #include, #import, #inject, #envar, #line, #filename, debugger, #if/#else/#endif, bitwise operators (&, \|, <<, >>, >>>) | | greyscript-core | import_code |

Install

npm install greyscript-core

Usage

import { Parser } from 'greyscript-core';

const code = `
import_code("networking.src")
#include "utils.src"
print("hello")
`;

const parser = new Parser(code, {
  filename: 'main.src'
});
const chunk = parser.parseChunk();

console.log(chunk.nativeImports); // [ASTImportCodeExpression]
console.log(chunk.includes);      // [ASTFeatureIncludeExpression]
console.log(chunk.toString());

Unsafe mode

import { UnsafeParser, UnsafeLexer } from 'greyscript-core';

const code = 'import_code("lib.src"\nprint("hello")';
const lexer = new UnsafeLexer(code);
const parser = new UnsafeParser(code, { lexer });

parser.parseChunk();

console.log(parser.errors); // recoverable errors
console.log(lexer.errors);  // lexer-level errors

Extending

greyscript-core follows the same extension patterns as miniscript-core and greybel-core. The keyword handler builder is available via greyscriptKeywordHandlerBuilder() and can be extended with additional entries.

GreyscriptParserState extends GreybelParserState with a nativeImports array. Subclasses that add their own state fields should override snapshot(), restore(), merge(), createEmpty(), and clone().

Testing

npm test