Source code
Revision control
Copy as Markdown
Other Tools
use crate::component::*;
use crate::core;
use crate::gensym;
use crate::kw;
use crate::token::Id;
use crate::token::{Index, Span};
use std::collections::HashMap;
use std::mem;
/// Performs an AST "expansion" pass over the component fields provided.
///
/// This expansion is intended to desugar the AST from various parsed constructs
/// to bits and bobs amenable for name resolution as well as binary encoding.
/// For example `(import "i" (func))` is split into a type definition followed by
/// the import referencing that type definition.
///
/// Most forms of AST expansion happen in this file and afterwards the AST will
/// be handed to the name resolution pass which will convert `Index::Id` to
/// `Index::Num` wherever it's found.
pub fn expand(fields: &mut Vec<ComponentField<'_>>) {
Expander::default().expand_component_fields(fields)
}
enum AnyType<'a> {
Core(CoreType<'a>),
Component(Type<'a>),
}
impl<'a> From<AnyType<'a>> for ComponentTypeDecl<'a> {
fn from(t: AnyType<'a>) -> Self {
match t {
AnyType::Core(t) => Self::CoreType(t),
AnyType::Component(t) => Self::Type(t),
}
}
}
impl<'a> From<AnyType<'a>> for InstanceTypeDecl<'a> {
fn from(t: AnyType<'a>) -> Self {
match t {
AnyType::Core(t) => Self::CoreType(t),
AnyType::Component(t) => Self::Type(t),
}
}
}
impl<'a> From<AnyType<'a>> for ComponentField<'a> {
fn from(t: AnyType<'a>) -> Self {
match t {
AnyType::Core(t) => Self::CoreType(t),
AnyType::Component(t) => Self::Type(t),
}
}
}
#[derive(Default)]
struct Expander<'a> {
/// Fields, during processing, which should be prepended to the
/// currently-being-processed field. This should always be empty after
/// processing is complete.
types_to_prepend: Vec<AnyType<'a>>,
component_fields_to_prepend: Vec<ComponentField<'a>>,
/// Fields that are appended to the end of the module once everything has
/// finished.
component_fields_to_append: Vec<ComponentField<'a>>,
}
impl<'a> Expander<'a> {
fn expand_component_fields(&mut self, fields: &mut Vec<ComponentField<'a>>) {
let mut cur = 0;
while cur < fields.len() {
self.expand_field(&mut fields[cur]);
let amt = self.types_to_prepend.len() + self.component_fields_to_prepend.len();
fields.splice(cur..cur, self.component_fields_to_prepend.drain(..));
fields.splice(cur..cur, self.types_to_prepend.drain(..).map(Into::into));
cur += 1 + amt;
}
fields.append(&mut self.component_fields_to_append);
}
fn expand_decls<T>(&mut self, decls: &mut Vec<T>, expand: fn(&mut Self, &mut T))
where
T: From<AnyType<'a>>,
{
let mut cur = 0;
while cur < decls.len() {
expand(self, &mut decls[cur]);
assert!(self.component_fields_to_prepend.is_empty());
assert!(self.component_fields_to_append.is_empty());
let amt = self.types_to_prepend.len();
decls.splice(cur..cur, self.types_to_prepend.drain(..).map(From::from));
cur += 1 + amt;
}
}
fn expand_field(&mut self, item: &mut ComponentField<'a>) {
let expanded = match item {
ComponentField::CoreModule(m) => self.expand_core_module(m),
ComponentField::CoreInstance(i) => {
self.expand_core_instance(i);
None
}
ComponentField::CoreType(t) => {
self.expand_core_type(t);
None
}
ComponentField::Component(c) => self.expand_nested_component(c),
ComponentField::Instance(i) => self.expand_instance(i),
ComponentField::Type(t) => {
self.expand_type(t);
None
}
ComponentField::CanonicalFunc(f) => {
self.expand_canonical_func(f);
None
}
ComponentField::CoreFunc(f) => self.expand_core_func(f),
ComponentField::Func(f) => self.expand_func(f),
ComponentField::Import(i) => {
self.expand_item_sig(&mut i.item);
None
}
ComponentField::Export(e) => {
if let Some(sig) = &mut e.ty {
self.expand_item_sig(&mut sig.0);
}
None
}
ComponentField::Start(_)
| ComponentField::Alias(_)
| ComponentField::Custom(_)
| ComponentField::Producers(_) => None,
};
if let Some(expanded) = expanded {
*item = expanded;
}
}
fn expand_core_module(&mut self, module: &mut CoreModule<'a>) -> Option<ComponentField<'a>> {
for name in module.exports.names.drain(..) {
let id = gensym::fill(module.span, &mut module.id);
self.component_fields_to_append
.push(ComponentField::Export(ComponentExport {
span: module.span,
id: None,
debug_name: None,
name,
kind: ComponentExportKind::module(module.span, id),
ty: None,
}));
}
match &mut module.kind {
// inline modules are expanded later during resolution
CoreModuleKind::Inline { .. } => None,
CoreModuleKind::Import { import, ty } => {
let idx = self.expand_core_type_use(ty);
Some(ComponentField::Import(ComponentImport {
span: module.span,
name: import.name,
item: ItemSig {
span: module.span,
id: module.id,
name: None,
kind: ItemSigKind::CoreModule(CoreTypeUse::Ref(idx)),
},
}))
}
}
}
fn expand_core_instance(&mut self, instance: &mut CoreInstance<'a>) {
match &mut instance.kind {
CoreInstanceKind::Instantiate { args, .. } => {
for arg in args {
self.expand_core_instantiation_arg(&mut arg.kind);
}
}
CoreInstanceKind::BundleOfExports { .. } => {}
}
}
fn expand_nested_component(
&mut self,
component: &mut NestedComponent<'a>,
) -> Option<ComponentField<'a>> {
for name in component.exports.names.drain(..) {
let id = gensym::fill(component.span, &mut component.id);
self.component_fields_to_append
.push(ComponentField::Export(ComponentExport {
span: component.span,
id: None,
debug_name: None,
name,
kind: ComponentExportKind::component(component.span, id),
ty: None,
}));
}
match &mut component.kind {
NestedComponentKind::Inline(fields) => {
expand(fields);
None
}
NestedComponentKind::Import { import, ty } => {
let idx = self.expand_component_type_use(ty);
Some(ComponentField::Import(ComponentImport {
span: component.span,
name: import.name,
item: ItemSig {
span: component.span,
id: component.id,
name: None,
kind: ItemSigKind::Component(ComponentTypeUse::Ref(idx)),
},
}))
}
}
}
fn expand_instance(&mut self, instance: &mut Instance<'a>) -> Option<ComponentField<'a>> {
for name in instance.exports.names.drain(..) {
let id = gensym::fill(instance.span, &mut instance.id);
self.component_fields_to_append
.push(ComponentField::Export(ComponentExport {
span: instance.span,
id: None,
debug_name: None,
name,
kind: ComponentExportKind::instance(instance.span, id),
ty: None,
}));
}
match &mut instance.kind {
InstanceKind::Import { import, ty } => {
let idx = self.expand_component_type_use(ty);
Some(ComponentField::Import(ComponentImport {
span: instance.span,
name: import.name,
item: ItemSig {
span: instance.span,
id: instance.id,
name: None,
kind: ItemSigKind::Instance(ComponentTypeUse::Ref(idx)),
},
}))
}
InstanceKind::Instantiate { args, .. } => {
for arg in args {
self.expand_instantiation_arg(&mut arg.kind);
}
None
}
InstanceKind::BundleOfExports { .. } => None,
}
}
fn expand_canonical_func(&mut self, func: &mut CanonicalFunc<'a>) {
match &mut func.kind {
CanonicalFuncKind::Lift { ty, .. } => {
self.expand_component_type_use(ty);
}
CanonicalFuncKind::Lower(_)
| CanonicalFuncKind::ResourceNew(_)
| CanonicalFuncKind::ResourceRep(_)
| CanonicalFuncKind::ResourceDrop(_) => {}
}
}
fn expand_core_func(&mut self, func: &mut CoreFunc<'a>) -> Option<ComponentField<'a>> {
match &mut func.kind {
CoreFuncKind::Alias(a) => Some(ComponentField::Alias(Alias {
span: func.span,
id: func.id,
name: func.name,
target: AliasTarget::CoreExport {
instance: a.instance,
name: a.name,
kind: core::ExportKind::Func,
},
})),
CoreFuncKind::Lower(info) => Some(ComponentField::CanonicalFunc(CanonicalFunc {
span: func.span,
id: func.id,
name: func.name,
kind: CanonicalFuncKind::Lower(mem::take(info)),
})),
CoreFuncKind::ResourceNew(info) => Some(ComponentField::CanonicalFunc(CanonicalFunc {
span: func.span,
id: func.id,
name: func.name,
kind: CanonicalFuncKind::ResourceNew(mem::take(info)),
})),
CoreFuncKind::ResourceDrop(info) => {
Some(ComponentField::CanonicalFunc(CanonicalFunc {
span: func.span,
id: func.id,
name: func.name,
kind: CanonicalFuncKind::ResourceDrop(mem::take(info)),
}))
}
CoreFuncKind::ResourceRep(info) => Some(ComponentField::CanonicalFunc(CanonicalFunc {
span: func.span,
id: func.id,
name: func.name,
kind: CanonicalFuncKind::ResourceRep(mem::take(info)),
})),
}
}
fn expand_func(&mut self, func: &mut Func<'a>) -> Option<ComponentField<'a>> {
for name in func.exports.names.drain(..) {
let id = gensym::fill(func.span, &mut func.id);
self.component_fields_to_append
.push(ComponentField::Export(ComponentExport {
span: func.span,
id: None,
debug_name: None,
name,
kind: ComponentExportKind::func(func.span, id),
ty: None,
}));
}
match &mut func.kind {
FuncKind::Import { import, ty } => {
let idx = self.expand_component_type_use(ty);
Some(ComponentField::Import(ComponentImport {
span: func.span,
name: import.name,
item: ItemSig {
span: func.span,
id: func.id,
name: None,
kind: ItemSigKind::Func(ComponentTypeUse::Ref(idx)),
},
}))
}
FuncKind::Lift { ty, info } => {
let idx = self.expand_component_type_use(ty);
Some(ComponentField::CanonicalFunc(CanonicalFunc {
span: func.span,
id: func.id,
name: func.name,
kind: CanonicalFuncKind::Lift {
ty: ComponentTypeUse::Ref(idx),
info: mem::take(info),
},
}))
}
FuncKind::Alias(a) => Some(ComponentField::Alias(Alias {
span: func.span,
id: func.id,
name: func.name,
target: AliasTarget::Export {
instance: a.instance,
name: a.name,
kind: ComponentExportAliasKind::Func,
},
})),
}
}
fn expand_core_type(&mut self, field: &mut CoreType<'a>) {
match &mut field.def {
CoreTypeDef::Def(_) => {}
CoreTypeDef::Module(m) => self.expand_module_ty(m),
}
let id = gensym::fill(field.span, &mut field.id);
let index = Index::Id(id);
match &field.def {
CoreTypeDef::Def(_) => {}
CoreTypeDef::Module(t) => t.key().insert(self, index),
}
}
fn expand_type(&mut self, field: &mut Type<'a>) {
match &mut field.def {
TypeDef::Defined(d) => self.expand_defined_ty(d),
TypeDef::Func(f) => self.expand_func_ty(f),
TypeDef::Component(c) => self.expand_component_ty(c),
TypeDef::Instance(i) => self.expand_instance_ty(i),
TypeDef::Resource(_) => {}
}
let id = gensym::fill(field.span, &mut field.id);
let index = Index::Id(id);
match &field.def {
TypeDef::Defined(t) => t.key().insert(self, index),
TypeDef::Func(t) => t.key().insert(self, index),
TypeDef::Component(t) => t.key().insert(self, index),
TypeDef::Instance(t) => t.key().insert(self, index),
TypeDef::Resource(_) => {}
}
for name in field.exports.names.drain(..) {
self.component_fields_to_append
.push(ComponentField::Export(ComponentExport {
span: field.span,
id: None,
debug_name: None,
name,
kind: ComponentExportKind::ty(field.span, id),
ty: None,
}));
}
}
fn expand_func_ty(&mut self, ty: &mut ComponentFunctionType<'a>) {
for param in ty.params.iter_mut() {
self.expand_component_val_ty(&mut param.ty);
}
for result in ty.results.iter_mut() {
self.expand_component_val_ty(&mut result.ty);
}
}
fn expand_module_ty(&mut self, ty: &mut ModuleType<'a>) {
use crate::core::resolve::types::{FuncKey, TypeKey, TypeReference};
// Note that this is a custom implementation from everything else in
// this file since this is using core wasm types instead of component
// types, so a small part of the core wasm expansion process is
// inlined here to handle the `TypeUse` from core wasm.
let mut func_type_to_idx = HashMap::new();
let mut to_prepend = Vec::new();
let mut i = 0;
while i < ty.decls.len() {
match &mut ty.decls[i] {
ModuleTypeDecl::Type(ty) => match &ty.def {
core::TypeDef::Func(f) => {
let id = gensym::fill(ty.span, &mut ty.id);
func_type_to_idx.insert(f.key(), Index::Id(id));
}
core::TypeDef::Struct(_) => {}
core::TypeDef::Array(_) => {}
},
ModuleTypeDecl::Alias(_) => {}
ModuleTypeDecl::Import(ty) => {
expand_sig(&mut ty.item, &mut to_prepend, &mut func_type_to_idx);
}
ModuleTypeDecl::Export(_, item) => {
expand_sig(item, &mut to_prepend, &mut func_type_to_idx);
}
}
ty.decls.splice(i..i, to_prepend.drain(..));
i += 1;
}
fn expand_sig<'a>(
item: &mut core::ItemSig<'a>,
to_prepend: &mut Vec<ModuleTypeDecl<'a>>,
func_type_to_idx: &mut HashMap<FuncKey<'a>, Index<'a>>,
) {
match &mut item.kind {
core::ItemKind::Func(t) | core::ItemKind::Tag(core::TagType::Exception(t)) => {
// If the index is already filled in then this is skipped
if t.index.is_some() {
return;
}
// Otherwise the inline type information is used to
// generate a type into this module if necessary. If the
// function type already exists we reuse the same key,
// otherwise a fresh type definition is created and we use
// that one instead.
let ty = t.inline.take().unwrap_or_default();
let key = ty.key();
if let Some(idx) = func_type_to_idx.get(&key) {
t.index = Some(*idx);
return;
}
let id = gensym::gen(item.span);
to_prepend.push(ModuleTypeDecl::Type(core::Type {
span: item.span,
id: Some(id),
name: None,
def: key.to_def(item.span),
parent: None,
final_type: None,
}));
let idx = Index::Id(id);
t.index = Some(idx);
}
core::ItemKind::Global(_)
| core::ItemKind::Table(_)
| core::ItemKind::Memory(_) => {}
}
}
}
fn expand_component_ty(&mut self, ty: &mut ComponentType<'a>) {
Expander::default().expand_decls(&mut ty.decls, |e, decl| match decl {
ComponentTypeDecl::CoreType(t) => e.expand_core_type(t),
ComponentTypeDecl::Type(t) => e.expand_type(t),
ComponentTypeDecl::Alias(_) => {}
ComponentTypeDecl::Export(t) => e.expand_item_sig(&mut t.item),
ComponentTypeDecl::Import(t) => e.expand_item_sig(&mut t.item),
})
}
fn expand_instance_ty(&mut self, ty: &mut InstanceType<'a>) {
Expander::default().expand_decls(&mut ty.decls, |e, decl| match decl {
InstanceTypeDecl::CoreType(t) => e.expand_core_type(t),
InstanceTypeDecl::Type(t) => e.expand_type(t),
InstanceTypeDecl::Alias(_) => {}
InstanceTypeDecl::Export(t) => e.expand_item_sig(&mut t.item),
})
}
fn expand_item_sig(&mut self, ext: &mut ItemSig<'a>) {
match &mut ext.kind {
ItemSigKind::CoreModule(t) => {
self.expand_core_type_use(t);
}
ItemSigKind::Func(t) => {
self.expand_component_type_use(t);
}
ItemSigKind::Component(t) => {
self.expand_component_type_use(t);
}
ItemSigKind::Instance(t) => {
self.expand_component_type_use(t);
}
ItemSigKind::Value(t) => {
self.expand_component_val_ty(&mut t.0);
}
ItemSigKind::Type(_) => {}
}
}
fn expand_defined_ty(&mut self, ty: &mut ComponentDefinedType<'a>) {
match ty {
ComponentDefinedType::Primitive(_)
| ComponentDefinedType::Flags(_)
| ComponentDefinedType::Enum(_) => {}
ComponentDefinedType::Record(r) => {
for field in r.fields.iter_mut() {
self.expand_component_val_ty(&mut field.ty);
}
}
ComponentDefinedType::Variant(v) => {
for case in v.cases.iter_mut() {
if let Some(ty) = &mut case.ty {
self.expand_component_val_ty(ty);
}
}
}
ComponentDefinedType::List(t) => {
self.expand_component_val_ty(&mut t.element);
}
ComponentDefinedType::Tuple(t) => {
for field in t.fields.iter_mut() {
self.expand_component_val_ty(field);
}
}
ComponentDefinedType::Option(t) => {
self.expand_component_val_ty(&mut t.element);
}
ComponentDefinedType::Result(r) => {
if let Some(ty) = &mut r.ok {
self.expand_component_val_ty(ty);
}
if let Some(ty) = &mut r.err {
self.expand_component_val_ty(ty);
}
}
ComponentDefinedType::Own(_) | ComponentDefinedType::Borrow(_) => {}
}
}
fn expand_component_val_ty(&mut self, ty: &mut ComponentValType<'a>) {
let inline = match ty {
ComponentValType::Inline(ComponentDefinedType::Primitive(_))
| ComponentValType::Ref(_) => return,
ComponentValType::Inline(inline) => {
self.expand_defined_ty(inline);
mem::take(inline)
}
};
// If this inline type has already been defined within this context
// then reuse the previously defined type to avoid injecting too many
// types into the type index space.
if let Some(idx) = inline.key().lookup(self) {
*ty = ComponentValType::Ref(idx);
return;
}
// And if this type isn't already defined we append it to the index
// space with a fresh and unique name.
let span = Span::from_offset(0); // FIXME(#613): don't manufacture
let id = gensym::gen(span);
self.types_to_prepend.push(inline.into_any_type(span, id));
let idx = Index::Id(id);
*ty = ComponentValType::Ref(idx);
}
fn expand_core_type_use<T>(
&mut self,
item: &mut CoreTypeUse<'a, T>,
) -> CoreItemRef<'a, kw::r#type>
where
T: TypeReference<'a>,
{
let span = Span::from_offset(0); // FIXME(#613): don't manufacture
let mut inline = match mem::take(item) {
// If this type-use was already a reference to an existing type
// then we put it back the way it was and return the corresponding
// index.
CoreTypeUse::Ref(idx) => {
*item = CoreTypeUse::Ref(idx.clone());
return idx;
}
// ... otherwise with an inline type definition we go into
// processing below.
CoreTypeUse::Inline(inline) => inline,
};
inline.expand(self);
// If this inline type has already been defined within this context
// then reuse the previously defined type to avoid injecting too many
// types into the type index space.
if let Some(idx) = inline.key().lookup(self) {
let ret = CoreItemRef {
idx,
kind: kw::r#type(span),
export_name: None,
};
*item = CoreTypeUse::Ref(ret.clone());
return ret;
}
// And if this type isn't already defined we append it to the index
// space with a fresh and unique name.
let id = gensym::gen(span);
self.types_to_prepend.push(inline.into_any_type(span, id));
let idx = Index::Id(id);
let ret = CoreItemRef {
idx,
kind: kw::r#type(span),
export_name: None,
};
*item = CoreTypeUse::Ref(ret.clone());
ret
}
fn expand_component_type_use<T>(
&mut self,
item: &mut ComponentTypeUse<'a, T>,
) -> ItemRef<'a, kw::r#type>
where
T: TypeReference<'a>,
{
let span = Span::from_offset(0); // FIXME(#613): don't manufacture
let mut inline = match mem::take(item) {
// If this type-use was already a reference to an existing type
// then we put it back the way it was and return the corresponding
// index.
ComponentTypeUse::Ref(idx) => {
*item = ComponentTypeUse::Ref(idx.clone());
return idx;
}
// ... otherwise with an inline type definition we go into
// processing below.
ComponentTypeUse::Inline(inline) => inline,
};
inline.expand(self);
// If this inline type has already been defined within this context
// then reuse the previously defined type to avoid injecting too many
// types into the type index space.
if let Some(idx) = inline.key().lookup(self) {
let ret = ItemRef {
idx,
kind: kw::r#type(span),
export_names: Vec::new(),
};
*item = ComponentTypeUse::Ref(ret.clone());
return ret;
}
// And if this type isn't already defined we append it to the index
// space with a fresh and unique name.
let id = gensym::gen(span);
self.types_to_prepend.push(inline.into_any_type(span, id));
let idx = Index::Id(id);
let ret = ItemRef {
idx,
kind: kw::r#type(span),
export_names: Vec::new(),
};
*item = ComponentTypeUse::Ref(ret.clone());
ret
}
fn expand_core_instantiation_arg(&mut self, arg: &mut CoreInstantiationArgKind<'a>) {
let (span, exports) = match arg {
CoreInstantiationArgKind::Instance(_) => return,
CoreInstantiationArgKind::BundleOfExports(span, exports) => (*span, mem::take(exports)),
};
let id = gensym::gen(span);
self.component_fields_to_prepend
.push(ComponentField::CoreInstance(CoreInstance {
span,
id: Some(id),
name: None,
kind: CoreInstanceKind::BundleOfExports(exports),
}));
*arg = CoreInstantiationArgKind::Instance(CoreItemRef {
kind: kw::instance(span),
idx: Index::Id(id),
export_name: None,
});
}
fn expand_instantiation_arg(&mut self, arg: &mut InstantiationArgKind<'a>) {
let (span, exports) = match arg {
InstantiationArgKind::Item(_) => return,
InstantiationArgKind::BundleOfExports(span, exports) => (*span, mem::take(exports)),
};
let id = gensym::gen(span);
self.component_fields_to_prepend
.push(ComponentField::Instance(Instance {
span,
id: Some(id),
name: None,
exports: Default::default(),
kind: InstanceKind::BundleOfExports(exports),
}));
*arg = InstantiationArgKind::Item(ComponentExportKind::instance(span, id));
}
}
trait TypeReference<'a> {
type Key: TypeKey<'a>;
fn key(&self) -> Self::Key;
fn expand(&mut self, cx: &mut Expander<'a>);
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a>;
}
impl<'a> TypeReference<'a> for ComponentDefinedType<'a> {
type Key = Todo; // FIXME(#598): should implement this
fn key(&self) -> Self::Key {
Todo
}
fn expand(&mut self, cx: &mut Expander<'a>) {
cx.expand_defined_ty(self)
}
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a> {
AnyType::Component(Type {
span,
id: Some(id),
name: None,
exports: Default::default(),
def: TypeDef::Defined(self),
})
}
}
impl<'a> TypeReference<'a> for ComponentType<'a> {
type Key = Todo; // FIXME(#598): should implement this
fn key(&self) -> Self::Key {
Todo
}
fn expand(&mut self, cx: &mut Expander<'a>) {
cx.expand_component_ty(self)
}
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a> {
AnyType::Component(Type {
span,
id: Some(id),
name: None,
exports: Default::default(),
def: TypeDef::Component(self),
})
}
}
impl<'a> TypeReference<'a> for ModuleType<'a> {
type Key = Todo; // FIXME(#598): should implement this
fn key(&self) -> Self::Key {
Todo
}
fn expand(&mut self, cx: &mut Expander<'a>) {
cx.expand_module_ty(self)
}
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a> {
AnyType::Core(CoreType {
span,
id: Some(id),
name: None,
def: CoreTypeDef::Module(self),
})
}
}
impl<'a> TypeReference<'a> for InstanceType<'a> {
type Key = Todo; // FIXME(#598): should implement this
fn key(&self) -> Self::Key {
Todo
}
fn expand(&mut self, cx: &mut Expander<'a>) {
cx.expand_instance_ty(self)
}
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a> {
AnyType::Component(Type {
span,
id: Some(id),
name: None,
exports: Default::default(),
def: TypeDef::Instance(self),
})
}
}
impl<'a> TypeReference<'a> for ComponentFunctionType<'a> {
type Key = Todo; // FIXME(#598): should implement this
fn key(&self) -> Self::Key {
Todo
}
fn expand(&mut self, cx: &mut Expander<'a>) {
cx.expand_func_ty(self)
}
fn into_any_type(self, span: Span, id: Id<'a>) -> AnyType<'a> {
AnyType::Component(Type {
span,
id: Some(id),
name: None,
exports: Default::default(),
def: TypeDef::Func(self),
})
}
}
trait TypeKey<'a> {
fn lookup(&self, cx: &Expander<'a>) -> Option<Index<'a>>;
fn insert(&self, cx: &mut Expander<'a>, index: Index<'a>);
}
struct Todo;
impl<'a> TypeKey<'a> for Todo {
fn lookup(&self, _cx: &Expander<'a>) -> Option<Index<'a>> {
None
}
fn insert(&self, _cx: &mut Expander<'a>, _index: Index<'a>) {}
}