Appendix C: Built-in Types and Classes

The transpiler provides the following types, classes, and instances. None of them requires an import, and their names cannot be redefined.

Generic value types

Type	Variants / contents	Purpose
Option<T>	Some(T), None	A value that may be absent
Status<T>	Success, Failure(T)	Outcome of an operation with no produced value
Result<T; E>	Ok(T), Error(E)	Outcome of a computation that produces a value
box T	owned block holding a T	Linear handle to pool memory

Structures and enumerations

Type	Contents	Purpose
TimeVal	tv_sec, tv_usec	Time representation
SysPrintBase	Decimal, Hexadecimal	Numeric base for the print services

Resource classes

Instances of these classes are declared in the application module:

Class	Declaration	Access port type
Pool<T; N>	resource p : Pool<T; N>;	access Allocator<T>
Atomic<T>	resource a : Atomic<T> = { value = ... };	access AtomicAccess<T>
AtomicArray<T; N>	resource a : AtomicArray<T; N> = { values = [...] };	access AtomicArrayAccess<T; N>

The operations they offer through their access ports:

Port type	Operations
Allocator<T>	alloc(&mut Option<box T>), free(box T)
AtomicAccess<T>	load(&mut T), store(T)
AtomicArrayAccess<T; N>	load_index(usize, &mut T), store_index(usize, T)

Channels and emitters

Class	Declaration
MsgQueue<T; N>	channel c : MsgQueue<T; N>;
PeriodicTimer	emitter e : PeriodicTimer = { period = { tv_sec = ..., tv_usec = ... } };

Built-in event sources

These emitters exist without being declared; a sink port is wired to them directly:

Name	Event payload	Fires
system_init	TimeVal	Once, at system start-up
irq_N	u32 (vector)	On hardware interrupt N (per platform)
kbd_irq	u32	On console input (posix-gcc, behind enable-kbd-irq)

The system interface

The system_entry instance implements the SystemAPI interface and is deployed when enable-system-port is set in termina.yaml. It is reached through a port declared access SystemAPI and wired with <-> system_entry. Its procedures:

Group	Procedures	Typical call
Time	clock_get_uptime, delay_in	clock_get_uptime(&mut now)
Output	print, println, print_char	println(12, &msg)
Output (numeric)	print_<T> and println_<T> for every integer type, plus print_f32/f64 and println_f32/f64	println_u32(value, base)
Input	read	read(256, &mut buf, &mut nread)

Prelude functions

Function	Signature	Purpose
f32_to_bits	(f32) -> u32	Bit pattern of a single-precision value
f32_from_bits	(u32) -> f32	Single-precision value from a bit pattern
f64_to_bits	(f64) -> u64	Bit pattern of a double-precision value
f64_from_bits	(u64) -> f64	Double-precision value from a bit pattern