npm i struct-compile --save

This project provides a convenient function to create a JavaScript class from a C structure, for further parsing or creating binary data.

• Node.js >= 16.18.0

The main function is compile with the signature:

compile(string, [arch], [BufferImpl]) => object

import { compile } from 'struct-compile';

// also available for commonJS
// const { compile } = require('struct-compile');

const { Data, PDU } = compile(`
  //simple example
  struct Data {
    uint8_t c;
    int v;
    unsigned long da;
  };

  //@NE Network-endiannes for all members of this struct
  struct __attribute__((__packed__)) PDU {
    //Some useful comment
    char name /*in-between comment*/ [16];
    double dbl;
    int p;
  };
`);

// creating objects
const obj = new PDU();

obj.name = 'seva';
obj.dbl = 1.1;

console.log('PDU size: ', obj.length);
console.log('PDU buffer example: ', obj.buffer);

// parsing raw binary data
const parsed = new PDU(
  Buffer.from([0x73, 0x65, 0x76, 0x61,
               0x00, 0x00, 0x00, 0x00,
               0x00, 0x00, 0x00, 0x00,
               0x00, 0x00, 0x00, 0x00,
               0x3f, 0xf1, 0x99, 0x99,
               0x99, 0x99, 0x99, 0x9a,
               0x00, 0x00, 0x00, 0x00])
);

console.log(parsed.name.toString());
console.log(parsed.dbl);

The syntax for creating structures takes into account C rules for aligning objects within a structure, and auxiliary comments help to automatically set the endianness of the field. Learn more about alignment here and here.

An important note is that the input syntax is the subset of the C syntax, current syntax rules can be viewed here.

This project has been tailored with specific compatibilities and limitations. Below is a checklist highlighting the current state of support for various features:

Please note that while some features like bitfields, nested structures, and enums are not currently supported, the project is continually evolving. Contributions or suggestions for these areas are welcome.

If you have any ideas, or something is not working correctly, feel free to open an issue.