@isl-lang/typechecker

Semantic analyzer for ISL - validates AST, resolves types, and builds symbol tables.

Installation

``bash
npm install @isl-lang/typechecker

or

pnpm add @isl-lang/typechecker
`

Usage

`typescript
import { parse } from '@isl-lang/parser';
import { typecheck, TypeChecker } from '@isl-lang/typechecker';

const ast = parse(
domain UserManagement {
type User {
id: uuid
name: string
email: email
}

intent CreateUser {
input { name: string, email: email }
output { user: User }
}
}
);

// Quick validation
const result = typecheck(ast);

if (result.errors.length > 0) {
result.errors.forEach(err => console.error(err.message));
} else {
console.log('Type checking passed!');
console.log('Symbol table:', result.symbolTable);
}

// Or use the TypeChecker class for more control
const checker = new TypeChecker();
const checked = checker.check(ast);
`

API

$3

Perform type checking on an AST.

Returns:
- errors - Array of type errors found
- warnings - Array of type warnings
- symbolTable - Resolved symbol table
- typeMap - Map of nodes to their resolved types

$3

Class for incremental type checking with caching.

`typescript
const checker = new TypeChecker();

// Check multiple files
checker.addFile('user.isl', userAst);
checker.addFile('order.isl', orderAst);

// Get all errors
const errors = checker.getAllErrors();

// Get type for a specific node
const type = checker.getType(node);
`

Features

- Type inference - Infers types for expressions
- Contract validation - Validates pre/postconditions
- Cross-reference resolution - Resolves type references across domains
- Import validation - Validates imports and exports
- Incremental checking - Efficient re-checking of modified files

Error Types

`typescript
import { TypeError, TypeErrorCode } from '@isl-lang/typechecker';

// Error codes
TypeErrorCode.UNDEFINED_TYPE
TypeErrorCode.TYPE_MISMATCH
TypeErrorCode.DUPLICATE_DEFINITION
TypeErrorCode.INVALID_CONTRACT
``

Documentation

Full documentation: https://isl-lang.dev/docs/typechecker

Related Packages

- @isl-lang/parser - ISL parser
- @isl-lang/evaluator - Expression evaluator

License

MIT