bytes_ext

Byte conversion helpers for Crystal numeric types.

bytes_ext adds Rust-style byte conversion methods to integers and floats, making it easy to convert values to and from little-endian, big-endian, and native-endian byte arrays.

Installation

Add the shard to your application's shard.yml:

dependencies:
  bytes_ext:
    github: mamantoha/bytes_ext

Then require it:

require "bytes_ext"

API

The following methods are added to supported numeric types:

value.to_le_bytes
value.to_be_bytes
value.to_ne_bytes
value.to_bytes

The following class methods parse bytes back into values:

Int32.from_le_bytes(bytes)
Int32.from_be_bytes(bytes)
Int32.from_ne_bytes(bytes)
Int32.from_bytes(bytes)

to_ne_bytes and from_ne_bytes use native-endian byte order. to_bytes and from_bytes are native-endian by default, and also accept an explicit IO::ByteFormat.

Supported Types

• Int8, Int16, Int32, Int64, Int128
• UInt8, UInt16, UInt32, UInt64, UInt128
• Float32, Float64

Examples

Little Endian

i32 = 0x12345678_i32
bytes = i32.to_le_bytes
# => Bytes[0x78, 0x56, 0x34, 0x12]

Int32.from_le_bytes(bytes)
# => 0x12345678_i32

Big Endian

i32 = 0x12345678_i32
bytes = i32.to_be_bytes
# => Bytes[0x12, 0x34, 0x56, 0x78]

Int32.from_be_bytes(bytes)
# => 0x12345678_i32

Native Endian

i32 = 0x12345678_i32
bytes = i32.to_ne_bytes

Int32.from_ne_bytes(bytes)
# => 0x12345678_i32

Explicit Byte Format

i32 = 0x12345678_i32
bytes = i32.to_bytes(IO::ByteFormat::BigEndian)
# => Bytes[0x12, 0x34, 0x56, 0x78]

Int32.from_bytes(bytes, IO::ByteFormat::BigEndian)
# => 0x12345678_i32

Floats

f32 = 12.5_f32
bytes = f32.to_le_bytes
# => Bytes[0x00, 0x00, 0x48, 0x41]

Float32.from_le_bytes(bytes)
# => 12.5_f32

Development

Run the test suite with:

crystal spec

Contributing

1. Fork the repository.
2. Create a feature branch.
3. Make your changes with focused tests.
4. Open a pull request.

License

This shard is available under the MIT license. See LICENSE.