binparse

import { bp } from 'binparse';
const simpleParser = bp.object('SimpleObject', {
 id: bp.lu16,
 x: bp.u8,
 y: bp.u8,
});
const { value, offset } = simpleParser.read([0x01, 0x00, 0x01, 0x02]);
/** byte offset of where the reader finished */
offset; // 3
/** Parsed object */
value.id; // 0x01
value.x; // 0x01;
value.y; // 0x02
value.unk1; // Typescript error

Arrays

import { bp } from 'binparse';
const PointParser = bp.object('Point', {
 /** X Offset */
 x: bp.lu16,
 /** Y Offset */
 y: bp.lu16,
});
const PointsParser = bp.object('SimpleObject', {
 // Number of points to read
 length: bp.variable('len', bp.u8),
 // Array of points with length "len"
 points: bp.array('Points', PointParser, 'len'),
});
const points = PointsParser.read([0x01, 0x01, 0x00, 0x02, 0x00]);

BitFlags

import { bp } from 'binparse';
const FlagParser = bp.bits('Flags', {
 isRed: 1,
 isGreen: 1,
 isBlue: 1,
 isAlpha: 1,
});
const { value } = FlagParser.read([0b0101]);
value.isRed; // true
value.isGreen; // false
value.isBlue; // true
value.isAlpha; // false

Explicit offsets

import { bp } from 'binparse';
const sparseParser = bp.object('Sparse', {
 first: bp.at(0x30, bp.lu32), // Read a lu32 at 0x30
 second: bp.at(0x60, bp.lu32), // Read a lu32 at 0x60
});
sparseParser.size; // 0x64

Performance