Module combinators

Combinators for composing and building complex encodables.

This module provides utility types for building complex Encodable types from simpler ones. These combinators allow common operations for encoding values, such as conditional encoding, prefixes or custom byte ordering.

These building blocks follow the Encodable trait interface and can be nested or chained together to define rich encoding behavior with minimal boilerplate.

Categories of Encodables

Primitive and Built-in Encodables

These are the basic types that can be directly encoded.

Type	Description
(...)	Encodes a tuple by encoding each element in order
i8 and u8	Encodes a single byte
char	Encodes a character as its UTF-8 byte representation
str	Encodes a UTF-8 string slice
CStr	Encodes a C string slice, including the null terminator (\0)
[u8; N]	Encodes a byte array
[u8]	Encodes a byte slice
[bool; 8]	Encodes a set of flags as a single byte
Arguments	Encodes formatted data from format_args with zero allocations

Composition and Flow Combinators

These types wrap or transform other encodables, allowing conditional encoding, iteration, or control over the format and structure of the output.

Type	Description
Option	Encodes the inner value if Some; does nothing if None
Result	Encodes the value on Ok; returns the error on Err
Cond	Encodes a value only if a condition is met
LE	Encodes a number in little-endian order
BE	Encodes a number in big-endian order
LengthPrefix	Encodes a length prefixed value (TLV)
Separated	Encodes a sequence of encodables separated by a given delimiter
Iter	Encodes a sequence of encodables
FromError	Transforms the error type of an encodable.

Alloc Encodables (requires the alloc OR std features)

These types are supported when the alloc or std feature is enabled.

Type	Description
Vec<u8>	Encodes a byte vector as a contiguous sequence of bytes
String	Encodes a heap-allocated UTF-8 string
CString	Encodes a C-style string including the null terminator (\0)
Box<T>	Encodes the value pointed to by a Box, as if it were directly encoded

Structs

BE

Encodes a number in big-endian order.

Cond

Encodes a value only if a condition is met

FlagsDeprecated

Encodes a set of bit flags packed into a single byte

FromError

Transforms the error type of an encodable.

Iter

Encodes a sequence of encodables.

LE

Encodes a number in little-endian order.

LengthPrefix

Encodes a length prefixed value (TLV).

Separated

Encodes a sequence of encodables separated by a given delimiter.