Enum Helper 

pub enum Helper {
    LoadConstant,
    Unary,
    Binary,
    CreateObject,
    CreateArray,
    CreateCell,
    CreateClosure,
    GetProperty,
    SetProperty,
    DeleteProperty,
    Call,
    Construct,
    Import,
    Truthy,
    ResumeValue,
    DefineAccessor,
    LoadGlobal,
    StoreGlobal,
    TypeOfGlobal,
    LoadThis,
    LoadArguments,
    LoadNewTarget,
    ArrayPush,
    ArrayExtend,
    ObjectSpread,
    SetPrototype,
    CreatePrivateName,
    CreateRegExp,
    GetIterator,
    IteratorNext,
    Export,
    ConsumeFuel,
}

A runtime routine the lowered code calls but does not define. Backends resolve each Helper::symbol to an address (JIT) or relocation (AOT).

Stable helper table

The variant order below is the canonical external_index order and the public contract a backend and the runtime link against. frame (i64) leads and out (*mut Completion, i64) trails every completion helper; runtime Values are i64; small integer selectors and indices are i32.

idx	variant	params after frame (before out)
0	LoadConstant	const_id: i32
1	Unary	op: i32, operand: i64
2	Binary	op: i32, left: i64, right: i64
3	CreateObject	—
4	CreateArray	—
5	CreateClosure	function_id: i32, captures: i64
6	GetProperty	object: i64, key: i64
7	SetProperty	object: i64, key: i64, value: i64
8	DeleteProperty	object: i64, key: i64
9	Call	callee: i64, this: i64, arguments: i64
10	Construct	callee: i64, arguments: i64
11	Import	specifier: i32
12	Truthy	value: i64 → i32 (no out, total)
13	ResumeValue	—
14	DefineAccessor	object: i64, key: i64, accessor: i64, kind: i32
15	LoadGlobal	name: i32
16	StoreGlobal	name: i32, value: i64
17	TypeOfGlobal	name: i32 (total)
18	LoadThis	— (total)
19	LoadArguments	— (total)
20	LoadNewTarget	— (total)
21	ArrayPush	array: i64, value: i64
22	ArrayExtend	array: i64, iterable: i64
23	ObjectSpread	target: i64, source: i64
24	SetPrototype	object: i64, prototype: i64
25	CreatePrivateName	description: i32 (total)
26	CreateRegExp	pattern: i32, flags: i32
27	GetIterator	src: i64, kind: i32
28	IteratorNext	iterator: i64, done_reg: i32, value_reg: i32 (two-write)
29	Export	name: i32, src: i64
30	ConsumeFuel	amount: i32 (total except FatalTrap)
31	CreateCell	—

Every helper except Helper::Truthy returns a bamts_native::CompletionTag. Helper::Truthy returns 0/1.

Variants

LoadConstant

bamts_load_constant(frame, const_id, out): materialize the module constant named by const_id into out.value.

Unary

bamts_unary(frame, op, operand, out): apply the unary operator op (see [unary_op_selector]) to operand.

Binary

bamts_binary(frame, op, left, right, out): apply the binary operator op (see [binary_op_selector]) to left and right.

CreateObject

bamts_create_object(frame, out): fresh empty object into out.value.

CreateArray

bamts_create_array(frame, out): fresh empty array into out.value.

CreateCell

bamts_create_cell(frame, out): fresh compiler-private TDZ cell.

CreateClosure

bamts_create_closure(frame, function_id, captures, out): materialize a closure over the named function, binding the captured cells held in the captures array value, into out.value. The runtime reads the callee’s capture_count to copy the leading capture registers.

GetProperty

bamts_get_property(frame, object, key, out): out.value = object[key], with key a runtime value coerced to a property key.

SetProperty

bamts_set_property(frame, object, key, value, out): object[key] = value.

DeleteProperty

bamts_delete_property(frame, object, key, out): out.value = delete object[key].

Call

bamts_call(frame, callee, this, arguments, out): call callee with receiver this over the dynamic arguments array value.

Construct

bamts_construct(frame, callee, arguments, out): construct with callee over the dynamic arguments array value.

Import

bamts_import(frame, specifier, out): import the module named by the string constant specifier into out.value.

Truthy

bamts_truthy(frame, value) -> u32: the total ToBoolean coercion, returning 1 when value is truthy and 0 otherwise. Never throws and never writes out.

ResumeValue

bamts_resume_value(frame, out): write the verified resumed value for frame into out.value. Resolves the resume-input gap in the native entry ABI (see the crate docs); may return Throw (generator.throw) or FatalTrap.

DefineAccessor

bamts_define_accessor(frame, object, key, accessor, kind, out): install a getter or setter (kind, see [accessor_kind_selector]) under key.

LoadGlobal

bamts_load_global(frame, name, out): out.value = globalThis[name]; throws a ReferenceError for an undeclared global.

StoreGlobal

bamts_store_global(frame, name, value, out): globalThis[name] = value.

TypeOfGlobal

bamts_typeof_global(frame, name, out): out.value = typeof globalThis[name]; total, yielding "undefined" for an undeclared global.

LoadThis

bamts_load_this(frame, out): load the this binding into out.value. Total.

LoadArguments

bamts_load_arguments(frame, out): load the arguments object into out.value. Total.

LoadNewTarget

bamts_load_new_target(frame, out): load new.target into out.value. Total.

ArrayPush

bamts_array_push(frame, array, value, out): append value to array.

ArrayExtend

bamts_array_extend(frame, array, iterable, out): spread iterable onto the end of array.

ObjectSpread

bamts_object_spread(frame, target, source, out): copy the own enumerable properties of source onto target.

SetPrototype

bamts_set_prototype(frame, object, prototype, out): set the [[Prototype]] of object.

CreatePrivateName

bamts_create_private_name(frame, description, out): create a fresh private name into out.value. Total.

CreateRegExp

bamts_create_regexp(frame, pattern, flags, out): build a RegExp from the string-constant pattern and flags into out.value.

GetIterator

bamts_get_iterator(frame, src, kind, out): acquire an iterator over src using protocol kind (see [iterator_kind_selector]).

IteratorNext

bamts_iterator_next(frame, iterator, done_reg, value_reg, out): advance iterator, writing the done flag into handles[done_reg] and the produced value into handles[value_reg] directly (two writes). On Throw, the thrown handle is in out.value and neither slot is written.

Export

bamts_export(frame, name, src, out): export the local value src under the string constant name.

ConsumeFuel

bamts_consume_fuel(frame, amount, out): reserve amount bytecode instructions from the shared machine budget. Returns FatalTrap on exhaustion and never routes through a bytecode exception handler.

Implementations

impl Helper

pub const fn symbol(self) -> &'static str

The C symbol the backend links against.

pub const fn external_index(self) -> u32

The stable helper index within HELPER_NAMESPACE; the index of the u1:<index> external name a backend must resolve to Helper::symbol.

pub const fn from_external_index(index: u32) -> Option<Helper>

The helper for a HELPER_NAMESPACE external-name index, inverting Helper::external_index. Returns None for an unknown index.

Trait Implementations

impl Clone for Helper

fn clone(&self) -> Helper

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Helper

impl Debug for Helper

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Helper

impl Hash for Helper

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Helper

fn cmp(&self, other: &Helper) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Helper

fn eq(&self, other: &Helper) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for Helper

fn partial_cmp(&self, other: &Helper) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Helper