token-types
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6.0.0 • Public • Published

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token-types

A primitive token library used to read and write from a Uint8Array. Although it is possible to use this module directly, it is primarily designed to be used with strtok3 tokenizer.

Compatibility

Module: version 5 migrated from CommonJS to pure ECMAScript Module (ESM). JavaScript is compliant with ECMAScript 2019 (ES10).

Installation

npm install --save token-types

Usually in combination with strtok3:

npm install --save strtok3

Using TypeScript you should also install @tokenizer/token as a development dependency:

npm install --save-dev @tokenizer/token

Example

import * as strtok3 from 'strtok3';
import * as token from 'token-types';

(async () => {

  const tokenizer = await strtok3.fromFile("somefile.bin");
  try {
    const myNumber = await tokenizer.readToken(token.Float32_BE);
    console.log(`My number: ${myNumber}`);
  } finally {
    tokenizer.close(); // Close the file
  }
})();

Tokens

Numeric tokens

token-types supports a wide variety of numeric tokens out of the box:

Token Number Bits Endianness
UINT8 Unsigned integer 8 n/a
UINT16_BE Unsigned integer 16 big endian
UINT16_LE Unsigned integer 16 little endian
UINT24_BE Unsigned integer 24 big endian
UINT24_LE Unsigned integer 24 little endian
UINT32_BE Unsigned integer 32 big endian
UINT32_LE Unsigned integer 32 little endian
UINT64_BE Unsigned integer 64 big endian
UINT64_LE* Unsigned integer 64 little endian
INT8 Signed integer 8 n/a
INT16_BE Signed integer 16 big endian
INT16_LE Signed integer 16 little endian
INT24_BE Signed integer 24 big endian
INT24_LE Signed integer 24 little endian
INT32_BE Signed integer 32 big endian
INT32_LE Signed integer 32 little endian
INT64_BE Signed integer 64 big endian
INT64_LE* Signed integer 64 little endian
Float16_BE IEEE 754 float 16 big endian
Float16_LE IEEE 754 float 16 little endian
Float32_BE IEEE 754 float 32 big endian
Float32_LE IEEE 754 float 32 little endian
Float64_BE IEEE 754 float 64 big endian
Float64_LE IEEE 754 float 64 little endian
Float80_BE* IEEE 754 float 80 big endian
Float80_LE* IEEE 754 float 80 little endian

(*) The tokens exceed the JavaScript IEEE 754 64-bit Floating Point precision, decoding and encoding is best effort based.

String tokens

StringType decoding is implemented using TextDecoder which supports a large number of encodings including but not limited to:

  • UTF-8 (the default)
  • Windows-1252
  • ISO-8859-1

Check out the MDN web docs for the TextDecoder for a complete list

Custom tokens

Custom tokens can be added, suitable for reading binary files or network messages:

  ExtendedHeader = {
    len: 10,

    get: (buf, off) => {
      return {
        // Extended header size
        size: Token.UINT32_BE.get(buf, off),
        // Extended Flags
        extendedFlags: Token.UINT16_BE.get(buf, off + 4),
        // Size of padding
        sizeOfPadding: Token.UINT32_BE.get(buf, off + 6),
        // CRC data present
        crcDataPresent: common.strtokBITSET.get(buf, off + 4, 31)
      };
    }
  };

Dependencies (2)

Dev Dependencies (21)

Package Sidebar

Install

npm i token-types

Weekly Downloads

5,094,306

Version

6.0.0

License

MIT

Unpacked Size

22.8 kB

Total Files

5

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Collaborators

  • borewit