Bytes Functions and Operators​

bytes

Byte sequence

bytes[i]

Bytes indexing.

bytes[from:to]

Bytes slicing.

bytes ++ bytes

Bytes concatenation.

= != ?= ?!= < > <= >=

Comparison operators

len()

Returns the number of bytes.

contains()

Check if the byte sequence contains a subsequence.

find()

Find the index of the first occurrence of a subsequence.

bytes_get_bit()

Get the nth bit of the bytes value.

type

bytes

Bytes - 图1

bytes

A sequence of bytes representing raw data.

There’s a special byte literal:

  1. select b'Hello, world';
  1. {b'Hello, world'}
  1. select b'Hello,\x20world\x01';
  1. {b'Hello, world\x01'}

There are also some generic functions that can operate on bytes:

  1. select contains(b'qwerty', b'42');
  1. {false}

It is possible to cast between bytes and json. Bytes are represented as base64 encoded strings in json.:

  1. select <json>b'Hello EdgeDB!';
  1. {"\"SGVsbG8gRWRnZURCIQ==\""}
  1. select <bytes>to_json("\"SGVsbG8gRWRnZURCIQ==\"");
  1. {b'Hello EdgeDB!'}

operator

bytes[i]

Bytes - 图2

bytes [ int64 ] -> bytes

Bytes indexing.

Examples:

  1. select b'binary \x01\x02\x03\x04 ftw!'[8];
  1. {b'\x02'}

operator

bytes[from:to]

Bytes - 图3

bytes [ int64 : int64 ] -> bytes

Bytes slicing.

Examples:

  1. select b'\x01\x02\x03\x04 ftw!'[2:-1];
  1. {b'\x03\x04 ftw'}
  1. select b'some bytes'[2:-3];
  1. {b'me by'}

operator

bytes ++ bytes

Bytes - 图4

bytes ++ bytes -> bytes

Bytes concatenation.

  1. select b'\x01\x02' ++ b'\x03\x04';
  1. {b'\x01\x02\x03\x04'}

function

bytes_get_bit()

Bytes - 图5

std::bytes_get_bit(bytes: bytes, nth: int64) -> int64

Get the nth bit of the bytes value.

When looking for the nth bit, this function enumerates bits from least to most significant in each byte.

  1. for n in {0, 1, 2, 3, 4, 5, 6, 7,
  2. 8, 9, 10, 11, 12, 13 ,14, 15}
  3. union bytes_get_bit(b'ab', n);
  1. {1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 1, 0}