Appendix A — Words, core ops and builtin ops

The text is where words are explained. This appendix gathers only tables to skim when you get stuck reading code. The word list is the same as the specification’s Appendix A, and anything not in that list is not a word.

The forty-eight words#

Kind	Words	Chapter
Declarations	module use type newtype struct enum trait contract actor state	chapters 21 and 13
ops	fn proc export unsafe extern satisfies	chapter 5
Locals	let var set keep	chapter 6
Flow	if else while for repeat range cycle next step guard match case return break continue try	chapter 7
Expressions and values	expr lit true false none	chapter 8
Concurrency	spawn send	chapter 25
Ownership	drop	chapter 19
Tests	test expect	chapter 31
Blocks	do end	chapter 3

Table 50.1 — All the words

rem and note are markers opening comments, and clause heads such as input, output, effects and requires and core ops such as add and len are not words but cannot be used as names.

Removed words#

Removed	Instead
loop	while true
give	return
unit	void
calcop · procop	fn · proc
is · as (in declarations) · local	Not written
to · in (field access)	field a. b . · idx a. i. .
on	proc inside an actor
fail	return error <variant>
; · ,	.
make	lit
index	idx
def struct·def enum·def type·def newtype (E-DEF-OLD)	delete def — struct · enum · type · newtype

Table 50.2 — Removed words and what to use instead (E-VOCAB-REMOVED)

as and to remain only as position markers in use … as <alias> and case <low> to <high>.

Frequently used core ops#

Kind	Operations
Arithmetic (stopping)	add sub mul div mod neg abs min max
Arithmetic (choosing the outcome)	wrap_* sat_* chk_* div_nz nonzero_of
Changing width	widen narrow narrow_wrap narrow_sat narrow_try cast bit_cast
Comparison and logic	eq ne lt le gt ge and or not
Bits	bit_and bit_or bit_xor bit_not shl shr rotl rotr wrap_shl wrap_shr count_ones leading_zeros trailing_zeros byte_swap
Sequences	len idx subslice view view_array same_slice copy
Groupings	field method isa payload
Answer-carrying types	some ok error is_some is_none is_ok is_error some_value ok_value error_value value_or
Translation time	size_of comptime config
Allocation	alloc_bytes
Atomic	atomic_load atomic_store atomic_add atomic_sub atomic_swap atomic_cas atomic_fence
Devices	read_volatile write_volatile
Concurrency	await drain channel chsend chrecv yield spawn send
Atomic (bits)	atomic_and atomic_or atomic_xor
Pipe stages — chapter 24	pipe map filter fold scan take skip zip enumerate collect count all any into
Lanes (SIMD) — chapter 27	splat load store load_masked store_masked lane_select lane_any lane_all reduce_add reduce_mul reduce_min reduce_max lane_avg native_lanes lane_reverse lane_rotate shuffle prefetch
Small-number sets — chapter 13	bitset_new bitset_count bitset_insert bitset_union bitset_intersect bitset_difference bitset_complement bitset_contains bitset_is_subset bitset_is_empty bitset_remove
Layouts and views — chapter 13	encode try_view view_segments capacity
Borrows and regions — chapter 12 · chapter 18	ref mut_ref deref borrow region stack_new stack_count push pop swap
Contracts and errors — chapter 14	range ret expect panic elem_lt elem_le elem_gt elem_ge
Builtin ops (computation) — stand only after call_builtin	clmul_lo clmul_hi mul_hi aes_round aes_round_last aes_ctr ghash chacha20 poly1305 aes_gcm chacha_poly sha256 sha384 sha512 crc32 hash_bytes rng_next
C strings and callbacks — chapter 29	cstr_of str_from_cstr unsafe_fn
Builtin ops (files, network, processes) — only after call_builtin	file_open file_read file_write file_seek file_close file_type link_type dir_open dir_read dir_close dir_make path_remove path_rename net_listen net_accept net_connect net_resolve net_send net_recv net_close net_pair net_port proc_spawn proc_read proc_poll proc_wait proc_kill
Builtin ops (standard I/O · arguments · environment · clock · terminal · random · reactor) — stand only after call_builtin	write_out read_in arg env_get time_now time_local time_sleep tty_raw tty_read tty_size random_bytes reactor_new r_read r_write
Builtin ops (floating-point functions) — stand only after call_builtin · chapter 4	sqrt sin cos exp log pow floor ceil round fmod sum_neumaier sum_seq

Table 50.3 — Kinds of core ops and builtin ops

★ Builtin ops have a name space of their own. They stand only in that position — call_builtin sha256 msg. out. . — and you may use the same spelling for a name of yours. Calling one bare when no name of yours is spelt that way is E-BUILTIN-BARE; naming something else after call_builtin is E-BUILTIN-NAME. Builtin ops are the material the system library is built from; a program calls the module that wraps them (chapter 32).

This table sorts every core op and builtin op of the canon into a group. The chapter next to each group name explains that group with examples. The one-line meanings are authoritative in the repository’s docs/spec/BUILTIN-MEANINGS.tsv.

Effects and capabilities#

Effect	Permitting capability	Chapter
io	cap io · file_system · net · tty · clock · random	chapter 16
alloc · heap	cap allocator · cap heap	chapters 18 and 20
atomic	cap atomic	chapter 27
device	cap mmio	chapter 30
unsafe	cap c · cap machine (depending on use)	chapters 29 and 30
state · panic · wait · concurrent	Written without capabilities	chapters 15 and 26

Table 50.4 — Effect atoms and their paired capabilities