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/*
* Copyright (c) Peter Bjorklund. All rights reserved. https://github.com/swamp/swamp
* Licensed under the MIT License. See LICENSE in the project root for license information.
*/
use crate::Analyzer;
use swamp_semantic::err::ErrorKind;
use swamp_semantic::{NormalPattern, Pattern, PatternElement};
use swamp_symbol::TopLevelSymbolId;
use swamp_types::prelude::EnumVariantType as TypesEnumVariantType;
use swamp_types::prelude::{EnumVariantCommon, TypeKind, TypeRef};
impl Analyzer<'_> {
fn find_variant_in_pattern(
&mut self,
expression_type: &TypeRef,
ast_name: &swamp_ast::Node,
) -> TypesEnumVariantType {
let enum_type_ref = if let TypeKind::Enum(enum_type_ref) = &*expression_type.kind {
enum_type_ref
} else {
self.add_err(ErrorKind::ExpectedEnumInPattern, ast_name);
return TypesEnumVariantType {
common: EnumVariantCommon {
symbol_id: TopLevelSymbolId::new_illegal(),
name: Default::default(),
assigned_name: String::new(),
container_index: 0,
},
payload_type: self.types().unit(),
};
};
let variant_name = self.get_text(ast_name).to_string();
if let Some(variant) = enum_type_ref.get_variant(&variant_name) {
variant.clone()
} else {
self.add_err(ErrorKind::UnknownEnumVariantTypeInPattern, ast_name);
TypesEnumVariantType {
common: EnumVariantCommon {
symbol_id: TopLevelSymbolId::new_illegal(),
name: Default::default(),
assigned_name: String::new(),
container_index: 0,
},
payload_type: self.types().unit(),
}
}
}
pub(crate) fn analyze_pattern(
&mut self,
ast_pattern: &swamp_ast::Pattern,
expected_condition_type: &TypeRef,
) -> (Pattern, bool, bool) {
match ast_pattern {
swamp_ast::Pattern::Wildcard(node) => {
(Pattern::Wildcard(self.to_node(node)), false, false)
}
swamp_ast::Pattern::ConcretePattern(node, concrete_pattern, maybe_guard) => {
let (normal_pattern, was_pushed, wanted_mutable) =
self.analyze_normal_pattern(node, concrete_pattern, expected_condition_type);
let resolved_guard =
maybe_guard
.as_ref()
.and_then(|guard_clause| match guard_clause {
swamp_ast::GuardClause::Wildcard(_) => None,
swamp_ast::GuardClause::Expression(clause_expr) => {
Some(self.analyze_bool_argument_expression(clause_expr))
}
});
(
Pattern::Normal(normal_pattern, resolved_guard),
was_pushed,
wanted_mutable,
)
}
}
}
#[allow(clippy::too_many_lines)]
pub(crate) fn analyze_normal_pattern(
&mut self,
node: &swamp_ast::Node,
ast_concrete_pattern: &swamp_ast::ConcretePattern,
expected_condition_type: &TypeRef,
) -> (NormalPattern, bool, bool) {
let mut anyone_wants_mutable = false;
match ast_concrete_pattern {
swamp_ast::ConcretePattern::EnumPattern(variant_name, destructuring_pattern) => {
let mut scope_was_pushed = false;
let enum_variant_type_ref =
self.find_variant_in_pattern(expected_condition_type, variant_name);
let name_node = self.to_node(node);
self.shared.state.refs.add(enum_variant_type_ref.common.symbol_id.into(), name_node.clone());
self.shared.definition_table.refs.add(enum_variant_type_ref.common.symbol_id.into(), name_node);
match destructuring_pattern {
swamp_ast::DestructuringPattern::Struct { fields } => {
if !scope_was_pushed {
self.push_block_scope("enum struct");
scope_was_pushed = true;
}
let mut resolved_elements = Vec::new();
match &*enum_variant_type_ref.payload_type.kind {
TypeKind::AnonymousStruct(anon_struct_type) => {
// For structs, can match any subset of fields in any order
for var in fields {
let var_name_str = self.get_text(&var.name).to_string();
// Check if the field exists
let Some(field_index) = anon_struct_type
.field_name_sorted_fields
.get_index(&var_name_str)
else {
return (
NormalPattern::Literal(
self.create_err(ErrorKind::UnknownField, &var.name),
),
false,
false,
);
};
let Some(field_type) = anon_struct_type
.field_name_sorted_fields
.get(&var_name_str)
else {
return (
NormalPattern::Literal(
self.create_err(ErrorKind::UnknownField, &var.name),
),
false,
false,
);
};
if var.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self.create_local_variable_parameter_like(
&var.name,
Option::from(&var.is_mutable),
&field_type.field_type,
false,
);
resolved_elements.push(PatternElement::VariableWithFieldIndex(
variable_ref,
field_index,
));
}
}
_ => {
return (
NormalPattern::Literal(
self.create_err(ErrorKind::CanNotDestructure, variant_name),
),
false,
false,
);
}
}
(
NormalPattern::EnumPattern(
enum_variant_type_ref,
Some(resolved_elements),
),
scope_was_pushed,
anyone_wants_mutable,
)
}
swamp_ast::DestructuringPattern::Tuple { elements } => {
if !scope_was_pushed {
self.push_block_scope("enum tuple");
scope_was_pushed = true;
}
assert!(elements.len() > 1, "internal error with tuple");
let mut resolved_elements = Vec::new();
if let TypeKind::Tuple(fields_in_order) =
&*enum_variant_type_ref.payload_type.kind
{
// For tuples, elements must be in order but can be partial
if elements.len() > fields_in_order.len() {
return (
NormalPattern::Literal(self.create_err(
ErrorKind::TooManyTupleFields {
max: fields_in_order.len(),
got: elements.len(),
},
variant_name,
)),
false,
false,
);
}
// Only zip with as many fields as we have elements
for (tuple_element_index, (element, field_type)) in
elements.iter().zip(fields_in_order).enumerate()
{
match element {
swamp_ast::PatternVariableOrWildcard::Variable(var) => {
if var.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self
.create_local_variable_parameter_like(
&var.name,
var.is_mutable.as_ref(),
field_type,
false,
);
resolved_elements.push(
PatternElement::VariableWithFieldIndex(
variable_ref,
tuple_element_index,
),
);
}
swamp_ast::PatternVariableOrWildcard::Wildcard(node) => {
resolved_elements
.push(PatternElement::Wildcard(self.to_node(node)));
}
}
}
(
NormalPattern::EnumPattern(
enum_variant_type_ref,
Some(resolved_elements),
),
scope_was_pushed,
anyone_wants_mutable,
)
} else {
self.add_err(ErrorKind::ExpectedTupleType, node);
(NormalPattern::PatternList(vec![]), false, false)
}
}
swamp_ast::DestructuringPattern::None { variable } => {
// Single payload variable - capture the entire payload
if !scope_was_pushed {
self.push_block_scope("enum payload");
scope_was_pushed = true;
}
if variable.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self.create_local_variable(
&variable.name,
variable.is_mutable.as_ref(),
&enum_variant_type_ref.payload_type,
false,
);
let payload_pattern_element = PatternElement::Variable(variable_ref);
(
NormalPattern::EnumPattern(
enum_variant_type_ref,
Some(vec![payload_pattern_element]),
),
scope_was_pushed,
anyone_wants_mutable,
)
}
swamp_ast::DestructuringPattern::Unit => {
// Unit enum variant with no payload - like `Red`, `Green`, `Blue`
(
NormalPattern::EnumPattern(enum_variant_type_ref, None),
scope_was_pushed,
anyone_wants_mutable,
)
}
}
}
swamp_ast::ConcretePattern::Literal(ast_literal) => (
self.analyze_pattern_literal(node, ast_literal, expected_condition_type),
false,
anyone_wants_mutable,
),
}
}
}