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/*
* Copyright (c) Peter Bjorklund. All rights reserved. https://github.com/swamp/script
* Licensed under the MIT License. See LICENSE in the project root for license information.
*/
use crate::Analyzer;
use crate::err::{Error, ErrorKind};
use swamp_script_semantic::{NormalPattern, Pattern, PatternElement};
use swamp_script_types::prelude::*;
impl Analyzer<'_> {
fn find_variant_in_pattern(
&self,
expression_type: &Type,
ast_name: &swamp_script_ast::Node,
) -> Result<EnumVariantType, Error> {
let enum_type_ref = match expression_type {
Type::Enum(enum_type_ref) => enum_type_ref,
_ => Err(self.create_err(ErrorKind::ExpectedEnumInPattern, ast_name))?,
};
let variant_name = self.get_text(ast_name).to_string();
enum_type_ref.get_variant(&variant_name).map_or_else(
|| Err(self.create_err(ErrorKind::UnknownEnumVariantTypeInPattern, ast_name)),
|found_variant| Ok(found_variant.clone()),
)
}
pub(crate) fn analyze_pattern(
&mut self,
ast_pattern: &swamp_script_ast::Pattern,
expected_condition_type: &Type,
) -> Result<(Pattern, bool, bool), Error> {
match ast_pattern {
swamp_script_ast::Pattern::Wildcard(node) => {
Ok((Pattern::Wildcard(self.to_node(node)), false, false))
}
swamp_script_ast::Pattern::NormalPattern(node, normal_pattern, maybe_guard) => {
let (normal_pattern, was_pushed, wanted_mutable) =
self.analyze_normal_pattern(node, normal_pattern, expected_condition_type)?;
let resolved_guard = if let Some(guard_clause) = maybe_guard {
match guard_clause {
swamp_script_ast::GuardClause::Wildcard(_) => None,
swamp_script_ast::GuardClause::Expression(clause_expr) => {
Some(self.analyze_bool_argument_expression(clause_expr)?)
}
}
} else {
None
};
Ok((
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_script_ast::Node,
ast_normal_pattern: &swamp_script_ast::NormalPattern,
expected_condition_type: &Type,
) -> Result<(NormalPattern, bool, bool), Error> {
let mut anyone_wants_mutable = false;
match ast_normal_pattern {
swamp_script_ast::NormalPattern::PatternList(elements) => {
let mut resolved_elements = Vec::new();
let mut scope_is_pushed = false;
for element in elements {
match element {
swamp_script_ast::PatternElement::Variable(var) => {
if !scope_is_pushed {
self.push_block_scope("pattern_list one variable");
scope_is_pushed = true;
}
if var.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self.create_local_variable(
&var.name,
Option::from(&var.is_mutable),
expected_condition_type,
)?;
resolved_elements.push(PatternElement::Variable(variable_ref));
}
swamp_script_ast::PatternElement::Expression(expr) => {
return Err(self.create_err(
ErrorKind::ExpressionsNotAllowedInLetPattern,
&expr.node,
));
}
swamp_script_ast::PatternElement::Wildcard(node) => {
resolved_elements.push(PatternElement::Wildcard(self.to_node(node)));
}
}
}
Ok((
NormalPattern::PatternList(resolved_elements),
scope_is_pushed,
anyone_wants_mutable,
))
}
swamp_script_ast::NormalPattern::EnumPattern(variant_name, maybe_elements) => {
let mut scope_was_pushed = false;
let enum_variant_type_ref =
self.find_variant_in_pattern(expected_condition_type, variant_name)?;
if let Some(elements) = maybe_elements {
let mut resolved_elements = Vec::new();
match enum_variant_type_ref {
EnumVariantType::Tuple(ref tuple_type) => {
// For tuples, elements must be in order but can be partial
if elements.len() > tuple_type.fields_in_order.len() {
return Err(self.create_err(
ErrorKind::TooManyTupleFields {
max: tuple_type.fields_in_order.len(),
got: elements.len(),
},
variant_name,
));
}
if !scope_was_pushed {
self.push_block_scope("enum tuple");
scope_was_pushed = true;
}
// Only zip with as many fields as we have elements
for (element, field_type) in
elements.iter().zip(&tuple_type.fields_in_order)
{
match element {
swamp_script_ast::PatternElement::Variable(var) => {
if var.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self.create_local_variable(
&var.name,
var.is_mutable.as_ref(),
field_type,
)?;
resolved_elements
.push(PatternElement::Variable(variable_ref));
}
swamp_script_ast::PatternElement::Wildcard(node) => {
resolved_elements
.push(PatternElement::Wildcard(self.to_node(node)));
}
swamp_script_ast::PatternElement::Expression(expr) => {
return Err(self.create_err(
ErrorKind::ExpressionsNotAllowedInLetPattern,
&expr.node,
));
}
}
}
}
EnumVariantType::Struct(ref struct_type) => {
if !scope_was_pushed {
self.push_block_scope("enum struct");
scope_was_pushed = true;
}
// For structs, can match any subset of fields in any order
for element in elements {
match element {
swamp_script_ast::PatternElement::Variable(var) => {
let var_name_str = self.get_text(&var.name).to_string();
// Check if the field exists
let field_index = struct_type
.anon_struct
.field_name_sorted_fields
.get_index(&var_name_str)
.ok_or_else(|| {
self.create_err(ErrorKind::UnknownField, &var.name)
})?;
let field_type = struct_type
.anon_struct
.field_name_sorted_fields
.get(&var_name_str)
.ok_or_else(|| {
self.create_err(ErrorKind::UnknownField, &var.name)
})?;
if var.is_mutable.is_some() {
anyone_wants_mutable = true;
}
let variable_ref = self.create_local_variable(
&var.name,
Option::from(&var.is_mutable),
&field_type.field_type,
)?;
resolved_elements.push(
PatternElement::VariableWithFieldIndex(
variable_ref,
field_index,
),
);
}
swamp_script_ast::PatternElement::Wildcard(node) => {
resolved_elements
.push(PatternElement::Wildcard(self.to_node(node)));
}
swamp_script_ast::PatternElement::Expression(expr) => {
return Err(self.create_err(
ErrorKind::ExpressionsNotAllowedInLetPattern,
&expr.node,
));
}
}
}
}
EnumVariantType::Nothing(_) => {
if !elements.is_empty() {
return Err(self
.create_err(ErrorKind::EnumVariantHasNoFields, variant_name));
}
}
}
Ok((
NormalPattern::EnumPattern(enum_variant_type_ref, Some(resolved_elements)),
scope_was_pushed,
anyone_wants_mutable,
))
} else {
Ok((
NormalPattern::EnumPattern(enum_variant_type_ref, None),
false,
anyone_wants_mutable,
))
}
}
swamp_script_ast::NormalPattern::Literal(ast_literal) => Ok((
self.analyze_pattern_literal(node, ast_literal, expected_condition_type)?,
false,
anyone_wants_mutable,
)),
}
}
}