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use super::*;
use crate::ir::{SemanticConstructor, WrapperKind};
impl Interpreter {
#[allow(dead_code)]
pub(super) fn match_pattern(
&self,
pattern: &Pattern,
value: &Value,
) -> Option<Vec<(String, Value)>> {
match pattern {
Pattern::Wildcard => Some(Vec::new()),
Pattern::Literal(lit) => {
let matches = match (lit, value) {
(Literal::Int(i), Value::Int(v)) => i == v,
(Literal::Float(f), Value::Float(v)) => f == v,
(Literal::Str(s), Value::Str(v)) => s == v,
(Literal::Bool(b), Value::Bool(v)) => b == v,
(Literal::Unit, Value::Unit) => true,
_ => false,
};
if matches { Some(Vec::new()) } else { None }
}
Pattern::Ident(name) => Some(vec![(name.clone(), value.clone())]),
Pattern::EmptyList => {
if list_len(value) == Some(0) {
Some(Vec::new())
} else {
None
}
}
Pattern::Cons(head, tail) => {
let (head_value, tail_value) = {
let items = list_view(value)?;
let (head_value, tail_items) = aver_rt::list_uncons_cloned(items)?;
(head_value, Value::List(tail_items))
};
let mut bindings = Vec::with_capacity(2);
if head != "_" {
bindings.push((head.clone(), head_value));
}
if tail != "_" {
bindings.push((tail.clone(), tail_value));
}
Some(bindings)
}
Pattern::Tuple(patterns) => {
let Value::Tuple(values) = value else {
return None;
};
if patterns.len() != values.len() {
return None;
}
let mut all = Vec::new();
for (p, v) in patterns.iter().zip(values.iter()) {
let sub = self.match_pattern(p, v)?;
all.extend(sub);
}
Some(all)
}
Pattern::Constructor(ctor_name, bindings) => {
match (self.classify_runtime_constructor_name(ctor_name), value) {
(SemanticConstructor::NoneValue, Value::None) => Some(Vec::new()),
(SemanticConstructor::Wrapper(WrapperKind::ResultOk), Value::Ok(inner)) => {
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), *inner.clone()));
}
Some(result)
}
(SemanticConstructor::Wrapper(WrapperKind::ResultErr), Value::Err(inner)) => {
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), *inner.clone()));
}
Some(result)
}
(SemanticConstructor::Wrapper(WrapperKind::OptionSome), Value::Some(inner)) => {
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), *inner.clone()));
}
Some(result)
}
// User-defined variant: match by fully-qualified constructor name.
(
SemanticConstructor::TypeConstructor {
qualified_type_name,
variant_name,
},
Value::Variant {
type_name,
variant,
fields,
..
},
) => {
if !Self::ctor_type_matches_runtime(&qualified_type_name, type_name)
|| variant_name != *variant
{
return None;
}
if !bindings.is_empty() && bindings.len() != fields.len() {
return None;
}
let mut result = Vec::with_capacity(bindings.len());
for (name, val) in bindings.iter().zip(fields.iter()) {
if name != "_" {
result.push((name.clone(), val.clone()));
}
}
Some(result)
}
_ => None,
}
}
}
}
/// NanValue-native match_pattern — used by the eval loop.
/// Takes `&mut self` because Cons pattern needs to allocate the tail list in arena.
pub(super) fn match_pattern_nv(
&mut self,
pattern: &Pattern,
value: NanValue,
) -> Option<Vec<(String, NanValue)>> {
match pattern {
Pattern::Wildcard => Some(Vec::new()),
Pattern::Literal(lit) => {
let matches = match lit {
Literal::Int(i) => value.is_int() && value.as_int(&self.arena) == *i,
Literal::Float(f) => value.is_float() && value.as_float() == *f,
Literal::Str(s) => {
value.is_string()
&& self.arena.get_string_value(value).as_str() == s.as_str()
}
Literal::Bool(b) => value.is_bool() && value.as_bool() == *b,
Literal::Unit => value.is_unit(),
};
if matches { Some(Vec::new()) } else { None }
}
Pattern::Ident(name) => Some(vec![(name.clone(), value)]),
Pattern::EmptyList => {
if value.is_list() && self.arena.list_is_empty_value(value) {
Some(Vec::new())
} else {
None
}
}
Pattern::Cons(head, tail) => {
if !value.is_list() {
return None;
}
let (head_val, tail_val) = self.arena.list_uncons(value)?;
let mut bindings = Vec::with_capacity(2);
if head != "_" {
bindings.push((head.clone(), head_val));
}
if tail != "_" {
bindings.push((tail.clone(), tail_val));
}
Some(bindings)
}
Pattern::Tuple(patterns) => {
if !value.is_tuple() {
return None;
}
let items: Vec<NanValue> = self.arena.get_tuple(value.arena_index()).to_vec();
if patterns.len() != items.len() {
return None;
}
let mut all = Vec::new();
for (p, v) in patterns.iter().zip(items.iter()) {
let sub = self.match_pattern_nv(p, *v)?;
all.extend(sub);
}
Some(all)
}
Pattern::Constructor(ctor_name, bindings) => {
match self.classify_runtime_constructor_name(ctor_name) {
SemanticConstructor::NoneValue => {
if value.is_none() {
Some(Vec::new())
} else {
None
}
}
SemanticConstructor::Wrapper(WrapperKind::ResultOk) => {
if !value.is_ok() {
return None;
}
let inner = value.wrapper_inner(&self.arena);
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), inner));
}
Some(result)
}
SemanticConstructor::Wrapper(WrapperKind::ResultErr) => {
if !value.is_err() {
return None;
}
let inner = value.wrapper_inner(&self.arena);
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), inner));
}
Some(result)
}
SemanticConstructor::Wrapper(WrapperKind::OptionSome) => {
if !value.is_some() {
return None;
}
let inner = value.wrapper_inner(&self.arena);
let mut result = Vec::with_capacity(1);
if let Some(name) = bindings.first()
&& name != "_"
{
result.push((name.clone(), inner));
}
Some(result)
}
SemanticConstructor::TypeConstructor {
qualified_type_name,
variant_name,
} => {
// User-defined variant
if !value.is_variant() {
return None;
}
let (type_name, runtime_variant_name, fields) =
if let Some((type_id, variant_id, inner)) =
value.inline_variant_info(&self.arena)
{
(
self.arena.get_type_name(type_id),
self.arena.get_variant_name(type_id, variant_id),
vec![inner],
)
} else {
let (type_id, variant_id, fields) =
value.variant_parts(&self.arena)?;
(
self.arena.get_type_name(type_id),
self.arena.get_variant_name(type_id, variant_id),
fields.to_vec(),
)
};
if !Self::ctor_type_matches_runtime(&qualified_type_name, type_name)
|| variant_name != runtime_variant_name
{
return None;
}
if !bindings.is_empty() && bindings.len() != fields.len() {
return None;
}
let mut result = Vec::with_capacity(bindings.len());
for (name, val) in bindings.iter().zip(fields.iter()) {
if name != "_" {
result.push((name.clone(), *val));
}
}
Some(result)
}
SemanticConstructor::Unknown(_) => None,
}
}
}
}
}