BinaryFormat.Length

Last updated 5 months ago

BinaryFormat.Length

Returns a binary format that limits the amount of data that can be read.

function (binaryFormat as function, optional length as nullable any) as function

Description

Returns a binary format that limits the amount of data that can be read. Both BinaryFormat.List and BinaryFormat.Binary can be used to read until end of the data. BinaryFormat.Length can be used to limit the number of bytes that are read. The binaryFormat parameter specifes the binary format to limit. The length parameter specifies the number of bytes to read. The length parameter may either be a number value, or a binary format value that specifies the format of the length value that appears that preceeds the value being read.

Category

Binary Formats.Limiting input

Examples

Limit the number of bytes read to 2 when reading a list of bytes.

let
binaryData = #binary({1, 2, 3}),
listFormat = BinaryFormat.Length(
BinaryFormat.List(BinaryFormat.Byte), 2)
in
listFormat(binaryData)

{1, 2}

Limit the number of byte read when reading a list of bytes to the byte value preceeding the list.

let
binaryData = #binary({1, 2, 3}),
listFormat = BinaryFormat.Length(
BinaryFormat.List(BinaryFormat.Byte), BinaryFormat.Byte)
in
listFormat(binaryData)

{2}