Coding standards

The naming, error-handling, memory and documentation rules shared by the HardFOC drivers, in brief.

The full text, with rationale and examples, is CODING_STANDARDS.md. When a driver's existing code uses a different but consistent style, match the file you are editing.

Naming

Element	Convention	Example
Public functions	PascalCase	Init(), EnableChannel()
Private functions	camelCase	checkInitialized(), transferFrame()
Member variables	snake_case with trailing _	comm_, initialized_
Static member variables	snake_case with trailing _	instance_count_
Global variables	g_ prefix, snake_case	g_transfer_count
Constants (constexpr, const)	UPPER_CASE	MAX_CHANNELS, CH_CTRL
Enum classes	PascalCase	DriverError, ChannelMode
Enum values (errors, states)	PascalCase	None, NotInitialized
Enum values (flags, bits)	UPPER_CASE	CRC_ERROR
Local variables, parameters	snake_case	current_value, current_ma
Type aliases, classes, structs	PascalCase	CommResult, ChannelConfig, MAX22200
Namespaces	lowercase (preferred)	max22200, tmc9660
Macros	UPPER_CASE	DEVICE_HPP
Files	lowercase with underscores	max22200_spi_interface.hpp
Repositories	lowercase with dashes	hf-max22200-driver

Prefer full words (channel, not ch) and put units in names (current_setpoint_ma_).

Code organisation

• Include guards (#ifndef DEVICE_HPP), then includes in the order: system headers, third-party headers, the driver's own headers.
• Classes list public, then protected, then private members; within a section constructors first and data members last.
• Fixed-width integer types (uint8_t, int32_t) for anything that maps to hardware.

Errors

• C++ drivers return results: std::expected on C++23, or the driver's own expected-style polyfill on C++20.
• C code returns status codes.
• Every call that can fail is checked and its error propagated; no silent fallbacks.

Memory and threads

• Stack and static storage first; RAII for every resource; smart pointers when dynamic allocation is unavoidable.
• Drivers are not thread-safe by default: the caller synchronises shared access unless a function is documented as thread-safe.
• Document which functions are thread-safe; protect shared state with std::atomic or a mutex, and prefer class members to globals.

Documentation

• Doxygen comments (@brief, @param, @return) on every public declaration.
• Inline comments say why, not what.
• Documentation sites follow the HardFOC documentation style guide.