Data types

Data types

When defining the remote function or notification signatures, the user may choose arguments and return values of several types. These types mostly make sense only in a context of Python definition file. Compost messages do not contain any metadata about contents, so it is basically possible to send anything. However, a type safe interface will be ensured by the code generated from the definition file.

This chapter goes through all the features and restrictions.

Primitive types

Table below lists all supported primitive Compost types, with the respective native type for each supported language.

Compost	C	Python	C#	Description
U8	uint8_t	int	byte	8-bit unsigned integer
I8	int8_t	int	sbyte	8-bit signed integer
U16	uint16_t	int	ushort	16-bit unsigned integer
I16	int16_t	int	short	16-bit signed integer
U32	uint32_t	int	uint	32-bit unsigned integer
I32	int32_t	int	int	32-bit signed integer
U64	uint64_t	int	ulong	64-bit unsigned integer
I64	int64_t	int	long	64-bit signed integer
F32	float	float	float	32-bit floating point - IEEE 754 binary32 or single
F64	double	float	double	64-bit floating point - IEEE 754 binary64 or double

All primitive types are always transmitted in big-endian.

Composite types

Primitive types can be further wrapped into more complex types.

• Enums
• Structs
• Lists

How you can use each type

Context	Primitive type	Enum	List	Struct
Remote function parameter	✅	✅	✅	✅
Remote function return value	✅	✅	✅	✅
Member of compost_struct	✅	✅	✅	✅
Inner type of a list	✅	❌	❌	❌
Notification parameter	✅	✅	✅	✅