Quickstart — WASM Runtime

@odata-filter/core-wasm is an AssemblyScript reimplementation of the core parser compiled to WebAssembly. Use it in environments where a native WASM runtime provides a performance advantage, or when you need to run the parser outside a standard Node.js context.

1. Install

npm i @odata-filter/core-wasm --save

2. Import (async)

AssemblyScript WASM modules are loaded asynchronously. Always await the import before calling any exported function.

const { tokenize, parse } = await import('@odata-filter/core-wasm');

3. Tokenize a Filter Expression

const { tokenize } = await import('@odata-filter/core-wasm');

const tokens = tokenize("country/name eq 'US' and age gte 21");
console.log(tokens);

4. Parse into an AST

const { tokenize, parse } = await import('@odata-filter/core-wasm');

const tokens = tokenize("country/name eq 'US' and age gte 21");
const ast = parse(tokens);

console.log(JSON.stringify(ast, null, 2));

AST Shape Differences from the TypeScript Core

Because AssemblyScript does not support union types, Node.value in the WASM output is a flattened struct instead of a single typed value:

Field	Description
`format`	Numeric token format identifier
`raw`	Original token string
`stringValue`	String representation of the value
`intValue`	Integer representation (0 if not applicable)
`floatValue`	Float representation (0 if not applicable)
`boolValue`	Boolean representation (false if not applicable)
`arrayValue`	Array representation (empty if not applicable)

Example output for "country/name eq 'US' and age gte 21":

{
  "type": 3,
  "value": {
    "format": 1,
    "raw": "and",
    "stringValue": "and",
    "intValue": 0,
    "floatValue": 0,
    "boolValue": false,
    "arrayValue": []
  },
  "left": {
    "type": 1,
    "value": {
      "format": 1,
      "raw": "eq",
      "stringValue": "eq",
      "intValue": 0,
      "floatValue": 0,
      "boolValue": false,
      "arrayValue": []
    },
    "left": {
      "type": 4,
      "value": {
        "format": 1,
        "raw": "country/name",
        "stringValue": "country/name",
        "intValue": 0,
        "floatValue": 0,
        "boolValue": false,
        "arrayValue": []
      },
      "left": null,
      "right": null
    },
    "right": {
      "type": 5,
      "value": {
        "format": 1,
        "raw": "'US'",
        "stringValue": "US",
        "intValue": 0,
        "floatValue": 0,
        "boolValue": false,
        "arrayValue": []
      },
      "left": null,
      "right": null
    }
  }
}

5. When to Choose WASM vs Node.js

	Node.js (`@odata-filter/core`)	WASM (`@odata-filter/core-wasm`)
TypeScript-native	✓
Typed union `Node.value`	✓
Works in browser / edge runtimes		✓
Compatible with `@odata-filter/validation`	✓
Compatible with `@odata-filter/marshalers`	✓