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use crate::{
bytecompiler::{Access, ByteCompiler, Literal},
vm::{BindingOpcode, Opcode},
};
use boa_ast::{
pattern::{ArrayPatternElement, ObjectPatternElement, Pattern},
property::PropertyName,
};
impl ByteCompiler<'_, '_> {
pub(crate) fn compile_declaration_pattern_impl(
&mut self,
pattern: &Pattern,
def: BindingOpcode,
) {
match pattern {
Pattern::Object(pattern) => {
self.emit_opcode(Opcode::ValueNotNullOrUndefined);
self.emit_opcode(Opcode::RequireObjectCoercible);
let mut additional_excluded_keys_count = 0;
let rest_exits = pattern.has_rest();
for binding in pattern.bindings() {
use ObjectPatternElement::{
AssignmentPropertyAccess, AssignmentRestPropertyAccess, Pattern,
RestProperty, SingleName,
};
match binding {
// SingleNameBinding : BindingIdentifier Initializer[opt]
SingleName {
ident,
name,
default_init,
} => {
self.emit_opcode(Opcode::Dup);
self.emit_opcode(Opcode::Dup);
match name {
PropertyName::Literal(name) => {
let index = self.get_or_insert_name((*name).into());
self.emit(Opcode::GetPropertyByName, &[index]);
}
PropertyName::Computed(node) => {
self.compile_expr(node, true);
if rest_exits {
self.emit_opcode(Opcode::GetPropertyByValuePush);
} else {
self.emit_opcode(Opcode::GetPropertyByValue);
}
}
}
if let Some(init) = default_init {
let skip =
self.emit_opcode_with_operand(Opcode::JumpIfNotUndefined);
self.compile_expr(init, true);
self.patch_jump(skip);
}
self.emit_binding(def, *ident);
if rest_exits && name.computed().is_some() {
self.emit_opcode(Opcode::Swap);
additional_excluded_keys_count += 1;
}
}
// BindingRestProperty : ... BindingIdentifier
RestProperty {
ident,
excluded_keys,
} => {
self.emit_opcode(Opcode::PushEmptyObject);
for key in excluded_keys {
self.emit_push_literal(Literal::String(
self.interner().resolve_expect(key.sym()).into_common(false),
));
}
self.emit(
Opcode::CopyDataProperties,
&[excluded_keys.len() as u32, additional_excluded_keys_count],
);
self.emit_binding(def, *ident);
}
AssignmentRestPropertyAccess {
access,
excluded_keys,
} => {
self.emit_opcode(Opcode::Dup);
self.emit_opcode(Opcode::PushEmptyObject);
for key in excluded_keys {
self.emit_push_literal(Literal::String(
self.interner().resolve_expect(key.sym()).into_common(false),
));
}
self.emit(Opcode::CopyDataProperties, &[excluded_keys.len() as u32, 0]);
self.access_set(
Access::Property { access },
false,
ByteCompiler::access_set_top_of_stack_expr_fn,
);
}
AssignmentPropertyAccess {
name,
access,
default_init,
} => {
self.emit_opcode(Opcode::Dup);
self.emit_opcode(Opcode::Dup);
match name {
PropertyName::Literal(name) => {
let index = self.get_or_insert_name((*name).into());
self.emit(Opcode::GetPropertyByName, &[index]);
}
PropertyName::Computed(node) => {
self.compile_expr(node, true);
if rest_exits {
self.emit_opcode(Opcode::GetPropertyByValuePush);
} else {
self.emit_opcode(Opcode::GetPropertyByValue);
}
}
}
if let Some(init) = default_init {
let skip =
self.emit_opcode_with_operand(Opcode::JumpIfNotUndefined);
self.compile_expr(init, true);
self.patch_jump(skip);
}
self.access_set(
Access::Property { access },
false,
ByteCompiler::access_set_top_of_stack_expr_fn,
);
if rest_exits && name.computed().is_some() {
self.emit_opcode(Opcode::Swap);
additional_excluded_keys_count += 1;
}
}
Pattern {
name,
pattern,
default_init,
} => {
self.emit_opcode(Opcode::Dup);
self.emit_opcode(Opcode::Dup);
match name {
PropertyName::Literal(name) => {
let index = self.get_or_insert_name((*name).into());
self.emit(Opcode::GetPropertyByName, &[index]);
}
PropertyName::Computed(node) => {
self.compile_expr(node, true);
self.emit_opcode(Opcode::GetPropertyByValue);
}
}
if let Some(init) = default_init {
let skip =
self.emit_opcode_with_operand(Opcode::JumpIfNotUndefined);
self.compile_expr(init, true);
self.patch_jump(skip);
}
self.compile_declaration_pattern(pattern, def);
}
}
}
if !rest_exits {
self.emit_opcode(Opcode::Pop);
}
}
Pattern::Array(pattern) => {
self.emit_opcode(Opcode::ValueNotNullOrUndefined);
self.emit_opcode(Opcode::GetIterator);
for element in pattern.bindings() {
self.compile_array_pattern_element(element, def);
}
self.iterator_close(false);
}
}
}
fn compile_array_pattern_element(&mut self, element: &ArrayPatternElement, def: BindingOpcode) {
use ArrayPatternElement::{
Elision, Pattern, PatternRest, PropertyAccess, PropertyAccessRest, SingleName,
SingleNameRest,
};
match element {
// ArrayBindingPattern : [ Elision ]
Elision => {
self.emit_opcode(Opcode::IteratorNext);
}
// SingleNameBinding : BindingIdentifier Initializer[opt]
SingleName {
ident,
default_init,
} => {
self.emit_opcode(Opcode::IteratorNext);
self.emit_opcode(Opcode::IteratorValue);
if let Some(init) = default_init {
let skip = self.emit_opcode_with_operand(Opcode::JumpIfNotUndefined);
self.compile_expr(init, true);
self.patch_jump(skip);
}
self.emit_binding(def, *ident);
}
PropertyAccess { access } => {
self.access_set(Access::Property { access }, false, |compiler, _level| {
compiler.emit_opcode(Opcode::IteratorNext);
compiler.emit_opcode(Opcode::IteratorValue);
});
}
// BindingElement : BindingPattern Initializer[opt]
Pattern {
pattern,
default_init,
} => {
self.emit_opcode(Opcode::IteratorNext);
self.emit_opcode(Opcode::IteratorValue);
if let Some(init) = default_init {
let skip = self.emit_opcode_with_operand(Opcode::JumpIfNotUndefined);
self.compile_expr(init, true);
self.patch_jump(skip);
}
self.compile_declaration_pattern(pattern, def);
}
// BindingRestElement : ... BindingIdentifier
SingleNameRest { ident } => {
self.emit_opcode(Opcode::IteratorToArray);
self.emit_binding(def, *ident);
}
PropertyAccessRest { access } => {
self.access_set(Access::Property { access }, false, |compiler, _level| {
compiler.emit_opcode(Opcode::IteratorToArray);
});
}
// BindingRestElement : ... BindingPattern
PatternRest { pattern } => {
self.emit_opcode(Opcode::IteratorToArray);
self.compile_declaration_pattern(pattern, def);
}
}
}
}