Appendix A: Keywords

The following words are reserved by the Termina language and cannot be used as identifiers. They are listed here by the role they play.

Type names

Keyword	Role
u8 u16 u32 u64	Unsigned integer types
i8 i16 i32 i64	Signed integer types
usize	Unsigned machine-word integer
f32 f64	Floating-point types
bool	Boolean type
char	Character type
unit	The empty type (internal; not written in user code)

Type definitions

Keyword	Role
struct	Structure definition
enum	Enumeration definition
interface	Interface definition
class	Class definition, combined with task, handler, or resource

Type qualifiers

Keyword	Role
box	Owned block allocated from a pool
loc	Located (memory-mapped) field
const	Constant declaration
constexpr	Compile-time constant expression

Components and ports

Keyword	Role
task	Task class definition or task instance declaration
handler	Handler class definition or handler instance declaration
resource	Resource class definition or resource instance declaration
emitter	Event emitter instance declaration
channel	Message queue instance declaration
access	Access port to a resource
sink	Event sink port
in	Message input port
out	Message output port
triggers	Names the action a sink or input port activates
provides	Lists the interfaces a resource class implements
extends	Interface extension

Class members

Keyword	Role
function	Free function definition
procedure	Interface-visible operation of a resource class
method	Private helper of a class
action	Event response of a task or handler class
self	The receiving instance in a member's body

Statements and expressions

Keyword	Role
var	Mutable binding
let	Immutable binding
if / else	Conditional execution
match / case	Branching on a variant
for / while	Bounded iteration and its optional runtime guard
return	End of a body, with or without a value
continue	Tail transfer to another action of the same task
reboot	Platform-level system reset
as	Explicit type conversion
is	Variant test
true / false	Boolean literals
import	Module import

Reserved words

The words viewer, null, termina, option, and config are reserved by the toolchain and cannot be used as identifiers, although they do not currently appear in user programs.