Appendix D: Naming Conventions

The language does not enforce the following conventions, but the examples of this book, the demo applications, and the on-board software written in Termina all follow them. A consistent scheme makes the role of each identifier visible at the point of use.

Element	Convention	Examples
Task, handler, and resource classes	C prefix, PascalCase, kind suffix where it helps	CHKTask, CKbdIRQHandler, CTMChannel
Interfaces	I prefix, PascalCase	ITMChannel, ICounter, ISensorArray
Structs and enums	PascalCase	TCDescriptor, MissionOBT, CharDevIrqStatus
Enum variants	PascalCase	RxComplete, IrqError
Instances	snake_case, no prefix	hk_task, tm_channel, sample_pool
Functions, procedures, methods, actions	snake_case	accept_tc, do_housekeeping
Fields and variables	snake_case	interval_control, tc_pool_port
const globals	UPPER_SNAKE_CASE	TM_POOL_ALLOC_FAILURE
constexpr size constants	UPPER_SNAKE_CASE	SDP_NUM_PARAMS, SENSOR_ARRAY_SIZE
Unused parameters	leading underscore	_current_time, _vector

Port names

A port is named after what it connects to, with a suffix that recalls its role:

Port kind	Convention	Examples
Access port to a service	interface name without the I, snake_case, _port suffix	tm_channel_port, counter_port
Access port to a pool	content type plus _pool_port	tc_pool_port
Input port	in_ prefix or _input suffix	in_tc_channel, tc_message_queue_input
Output port	_out or _output suffix	tc_channel_out, frame_ready_output
Sink port	event name, _ev or descriptive	timer, irq, system_init_ev

Interface granularity

Service interfaces with a single natural implementor carry a plain noun (ITMChannel, IHKSubsystem). Capability interfaces that several classes may implement combine the noun with the capability (ICharDevSend, ICharDevNotifyIrq); a driver typically provides several of them, and each client is wired only to the facet it needs.

Modules

Module files and directories use snake_case, and the directory structure mirrors the import path: src/resources/tm_channel.fin is imported as resources.tm_channel. Modules are grouped by component kind: common/ for shared types, lib/ for functions, and resources/, tasks/, handlers/ for the classes.