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Typecheck Expressions - Permanently enable match ergonomics
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@thepowersgang
thepowersgang committed May 5, 2019
1 parent 4c4a7b8 commit 1f432b8
Showing 1 changed file with 53 additions and 64 deletions.
117 changes: 53 additions & 64 deletions src/hir_typeck/expr_cs.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -812,24 +812,18 @@ namespace {
{
TRACE_FUNCTION_F(&node << " match ...");

#if 1
const auto& val_type = node.m_value->m_res_type;
{
auto _ = this->push_inner_coerce_scoped(true);
this->context.add_ivars(node.m_value->m_res_type);

// TODO: If a coercion point (and ivar for the value) is placed here, it will allow `match &string { "..." ... }`
node.m_value->visit( *this );
}
#else
auto val_type = this->context.m_ivars.new_ivar_tr();

{
auto _ = this->push_inner_coerce_scoped(true);
this->context.add_ivars(node.m_value->m_res_type);

node.m_value->visit( *this );
this->context.equate_types_coerce( node.span(), val_type, node.m_value );
// TODO: If a coercion point (and ivar for the value) is placed here, it will allow `match &string { "..." ... }`
// - But, this can break some parts of inferrence
this->context.equate_types( node.span(), val_type, node.m_value->m_res_type );
//this->context.equate_types_coerce( node.span(), val_type, node.m_value );
}
#endif

for(auto& arm : node.m_arms)
{
Expand Down Expand Up @@ -3961,7 +3955,7 @@ void Context::handle_pattern(const Span& sp, ::HIR::Pattern& pat, const ::HIR::T

// NOTE: Even if the top-level is a binding, and even if the top-level type is fully known, match ergonomics
// still applies.
if( TARGETVER_1_29 && ! H2::has_ref_or_borrow(sp, pat) ) {
if( TARGETVER_1_29 ) { //&& ! H2::has_ref_or_borrow(sp, pat) ) {
// There's not a `&` or `ref` in the pattern, and we're targeting 1.29
// - Run the match ergonomics handler
// TODO: Default binding mode can be overridden back to "move" with `mut`
Expand Down Expand Up @@ -4132,8 +4126,6 @@ void Context::handle_pattern(const Span& sp, ::HIR::Pattern& pat, const ::HIR::T
{
pattern.m_binding.m_type = binding_mode;
}
unsigned n_deref = 0;
const auto* type_p = &type;
::HIR::TypeRef tmp;
const ::HIR::TypeRef* binding_type = nullptr;
switch(pattern.m_binding.m_type)
Expand All @@ -4143,30 +4135,17 @@ void Context::handle_pattern(const Span& sp, ::HIR::Pattern& pat, const ::HIR::T
break;
case ::HIR::PatternBinding::Type::MutRef:
// NOTE: Needs to deref and borrow to get just `&mut T` (where T isn't a &mut T)
//while( TU_TEST1(type_p->m_data, Borrow, .type >= ::HIR::BorrowType::Unique) )
//{
// n_deref ++;
// type_p = &context.m_ivars.get_type(*type_p->m_data.as_Borrow().inner);
//}
DEBUG(n_deref << " from " << type << " to " << *type_p);
binding_type = &(tmp = ::HIR::TypeRef::new_borrow(::HIR::BorrowType::Unique, type_p->clone()));
binding_type = &(tmp = ::HIR::TypeRef::new_borrow(::HIR::BorrowType::Unique, type.clone()));
break;
case ::HIR::PatternBinding::Type::Ref:
// NOTE: Needs to deref and borrow to get just `&mut T` (where T isn't a &mut T)
//while( type_p->m_data.is_Borrow() )
//{
// n_deref ++;
// type_p = &context.m_ivars.get_type(*type_p->m_data.as_Borrow().inner);
//}
DEBUG(n_deref << " from " << type << " to " << *type_p);
binding_type = &(tmp = ::HIR::TypeRef::new_borrow(::HIR::BorrowType::Shared, type_p->clone()));
binding_type = &(tmp = ::HIR::TypeRef::new_borrow(::HIR::BorrowType::Shared, type.clone()));
break;
default:
TODO(sp, "Assign variable type using mode " << (int)binding_mode << " and " << type);
}
assert(binding_type);
context.equate_types(sp, context.get_var(sp, pattern.m_binding.m_slot), *binding_type);
pattern.m_binding.m_implicit_deref_count = n_deref;
}

// For `_` patterns, there's nothing to match, so they just succeed with no derefs
Expand All @@ -4175,6 +4154,16 @@ void Context::handle_pattern(const Span& sp, ::HIR::Pattern& pat, const ::HIR::T
return true;
}

if( auto* pe = pattern.m_data.opt_Ref() )
{
// Require a &-ptr (hard requirement), then visit sub-pattern
auto inner_ty = context.m_ivars.new_ivar_tr();
auto new_ty = ::HIR::TypeRef::new_borrow( pe->type, inner_ty.clone() );
context.equate_types(sp, type, new_ty);

return this->revisit_inner( context, *pe->sub, inner_ty, binding_mode );
}

// If the type is a borrow, then count derefs required for the borrow
// - If the first non-borrow inner is an ivar, return false
unsigned n_deref = 0;
Expand Down Expand Up @@ -4590,68 +4579,68 @@ void Context::handle_pattern(const Span& sp, ::HIR::Pattern& pat, const ::HIR::T
// - I'll leave the option open, MIR generation should handle cases where there's multiple borrows
// or moves.
}
TU_MATCHA( (pat.m_data), (e),
(Any,
),
(Value,
),
(Range,
),
(Box,
TU_MATCH_HDRA( (pat.m_data), { )
TU_ARMA(Any, e) {
}
TU_ARMA(Value, e) {
}
TU_ARMA(Range, e) {
}
TU_ARMA(Box, e) {
create_bindings(sp, context, *e.sub);
),
(Ref,
}
TU_ARMA(Ref, e) {
create_bindings(sp, context, *e.sub);
),
(Tuple,
}
TU_ARMA(Tuple, e) {
for(auto& subpat : e.sub_patterns)
create_bindings(sp, context, subpat);
),
(SplitTuple,
}
TU_ARMA(SplitTuple, e) {
for(auto& subpat : e.leading) {
create_bindings(sp, context, subpat);
}
for(auto& subpat : e.trailing) {
create_bindings(sp, context, subpat);
}
),
(Slice,
}
TU_ARMA(Slice, e) {
for(auto& sub : e.sub_patterns)
create_bindings(sp, context, sub);
),
(SplitSlice,
}
TU_ARMA(SplitSlice, e) {
for(auto& sub : e.leading)
create_bindings(sp, context, sub);
// TODO: extra_bind
if( e.extra_bind.is_valid() ) {
TODO(sp, "Handle split slice binding binding in match ergonomics");
const auto& pb = e.extra_bind;
context.add_var( sp, pb.m_slot, pb.m_name, context.m_ivars.new_ivar_tr() );
}
for(auto& sub : e.trailing)
create_bindings(sp, context, sub);
),
}

// - Enums/Structs
(StructValue,
),
(StructTuple,
TU_ARMA(StructValue, e) {
}
TU_ARMA(StructTuple, e) {
for(auto& subpat : e.sub_patterns)
create_bindings(sp, context, subpat);
),
(Struct,
}
TU_ARMA(Struct, e) {
for(auto& field_pat : e.sub_patterns)
create_bindings(sp, context, field_pat.second);
),
(EnumValue,
),
(EnumTuple,
}
TU_ARMA(EnumValue, e) {
}
TU_ARMA(EnumTuple, e) {
for(auto& subpat : e.sub_patterns)
create_bindings(sp, context, subpat);
),
(EnumStruct,
}
TU_ARMA(EnumStruct, e) {
for(auto& field_pat : e.sub_patterns)
create_bindings(sp, context, field_pat.second);
)
)
}
}
}
};
// - Create variables, assigning new ivars for all of them.
Expand Down

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