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use super::*;
impl TypeChecker {
pub(super) fn check(&mut self, items: &[TopLevel], base_dir: Option<&str>) {
// Phase B: track the entry module's prefix so bare-name
// resolution in `resolve_fn_id` / `resolve_type_id` knows
// which scope to try first.
self.current_module_prefix = Self::module_decl(items).map(|m| m.name.clone());
// Load + integrate dependency modules FIRST so the alias
// maps are populated before `build_signatures` resolves local
// fn / type annotations.
let mut loaded_modules: Vec<crate::source::LoadedModule> = Vec::new();
if let Some(base) = base_dir
&& let Some(module) = Self::module_decl(items)
{
match crate::source::load_module_tree(&module.depends, base) {
Ok(modules) => {
self.integrate_loaded_modules(&modules);
loaded_modules = modules;
}
Err(e) => self.error(e),
}
}
self.build_signatures(items);
if !loaded_modules.is_empty() {
self.check_loaded_module_bodies(&loaded_modules);
}
self.check_body(items);
}
/// Type-check `items` against a caller-supplied list of already
/// loaded dependency modules (skips disk IO). Used by the
/// playground so multi-file projects stored in an in-browser map
/// type-check without touching a filesystem.
pub(super) fn check_with_loaded(
&mut self,
items: &[TopLevel],
loaded: &[crate::source::LoadedModule],
) {
// Phase B: track the entry module's prefix (see `check`).
self.current_module_prefix = Self::module_decl(items).map(|m| m.name.clone());
// Dependency aliases come in before local signatures so
// `build_signatures`'s resolution sees imported types
// (e.g. `Tile` resolves to `Types.Tile` when `Types` is in
// `depends`).
self.integrate_loaded_modules(loaded);
self.build_signatures(items);
self.check_loaded_module_bodies(loaded);
self.check_body(items);
}
fn integrate_loaded_modules(&mut self, modules: &[crate::source::LoadedModule]) {
// Phase B (peer review round 6): track each dep module's own
// `depends` list so the per-owner type resolver
// (`canonicalize_named_in_module`) can walk it instead of
// falling back to the importer's context or to whichever
// siblings happen to be in the entry's loaded tree.
for m in modules {
if let Some(module_decl) = TypeChecker::module_decl(&m.items) {
self.module_depends
.insert(m.dep_name.clone(), module_decl.depends.clone());
}
}
let pairs: Vec<_> = modules
.iter()
.map(|m| (m.dep_name.clone(), m.items.clone()))
.collect();
let registry = crate::visibility::SymbolRegistry::from_modules(&pairs);
if let Err(e) = self.integrate_registry(®istry) {
self.error(e);
}
}
/// Visit every function body in each loaded dependency module so the
/// per-`Spanned<Expr>` type slot gets populated. Without this, the
/// downstream codegen consumers (Step 2 legacy WASM, Step 1 Rust,
/// future wasm-gc) would see `Spanned::ty() == None` for everything in
/// dependent modules — which used to be patched over by per-backend
/// ad-hoc inference; the typed pipeline closes that gap properly.
///
/// Each module gets its own short-lived `TypeChecker` so unqualified
/// references inside the module resolve against that module's own
/// signatures (the parent checker only sees the qualified canonical
/// names from `integrate_loaded_modules`). `Spanned::set_ty` writes
/// straight to the shared AST node, so the type stamps survive the
/// sub-checker dropping. Diagnostics from the sub-check are folded
/// back into the parent so a real type bug in `combat.av` still
/// surfaces alongside any error in `main.av`.
fn check_loaded_module_bodies(&mut self, modules: &[crate::source::LoadedModule]) {
for module in modules {
// Phase B: clone the parent's `SymbolTable` into the sub-
// checker so every module shares the same opaque
// identity space. The dep module's own declarations are
// already registered in the table (the parent built it
// from `entry_items + dep_modules`).
let mut sub = TypeChecker::new_with_symbols(self.symbol_table.clone());
sub.self_host_mode = self.self_host_mode;
// Phase B: the dep module's prefix in the symbol table is
// its `dep_name` (the path the entry's `depends` clause
// wrote, e.g. `Pricing.Discount`), not the interior
// `module X` declaration inside the file. Use the
// `dep_name` so `resolve_fn_id` finds `mkDiscount` ->
// `FnKey::in_module(dep_name, "mkDiscount")` for own-module
// bodies in the sub-checker.
sub.current_module_prefix = Some(module.dep_name.clone());
// Phase B (peer review round 6): the sub-checker for
// module `B` must see `B`'s *own* depends — not every
// sibling the entry happened to load. The pre-fix sent
// `modules - self`, which let an unrelated sibling `C`
// (also a dep of the entry) leak into `B`'s resolver
// context and silently shadow types `B` genuinely
// depends on. Filter `modules` by the dep names listed
// in `B`'s own `depends [...]` declaration so the only
// bare-name aliases the sub-checker sees come from
// modules `B` itself imported.
let own_depends: Vec<String> = TypeChecker::module_decl(&module.items)
.map(|m| m.depends.clone())
.unwrap_or_default();
let visible_to_sub: Vec<_> = modules
.iter()
.filter(|m| own_depends.iter().any(|d| d == &m.dep_name))
.cloned()
.collect();
sub.integrate_loaded_modules(&visible_to_sub);
sub.build_signatures(&module.items);
sub.check_top_level_stmts(&module.items);
sub.check_verify_blocks(&module.items);
for item in &module.items {
if let TopLevel::FnDef(f) = item {
sub.check_fn(f);
}
}
self.errors.append(&mut sub.errors);
}
}
fn check_body(&mut self, items: &[TopLevel]) {
self.check_top_level_stmts(items);
self.check_verify_blocks(items);
for item in items {
if let TopLevel::FnDef(f) = item {
self.check_fn(f);
}
}
}
// ── Memo-safety analysis ─────────────────────────────────────────────
/// A type is memo-safe if its runtime values can be cheaply hashed and
/// compared for equality (scalars, records/variants of scalars).
pub(super) fn is_memo_safe(&self, ty: &Type, visiting: &mut HashSet<String>) -> bool {
match ty {
// String stays excluded for now: memo keys hash String content,
// so string-heavy recursion can degrade to O(n) keying work.
Type::Int | Type::Float | Type::Bool | Type::Unit => true,
Type::Str => false,
Type::Tuple(items) => items.iter().all(|item| self.is_memo_safe(item, visiting)),
Type::List(_)
| Type::Vector(_)
| Type::Map(_, _)
| Type::Fn(_, _, _)
| Type::Invalid
| Type::Var(_) => false,
Type::Result(_, _) | Type::Option(_) => false,
Type::Named { name, .. } => {
// Prevent infinite recursion for cyclic type defs
if !visiting.insert(name.clone()) {
return true;
}
let safe = self.named_type_memo_safe(name, visiting);
visiting.remove(name);
safe
}
}
}
/// Check whether a named user-defined type has only memo-safe fields.
pub(super) fn named_type_memo_safe(&self, name: &str, visiting: &mut HashSet<String>) -> bool {
// Iron — A5: `fields_for_type` resolves `name` through
// `sig_aliases` and returns one `(field_name, field_type)`
// per declared field; no dual-key arithmetic.
let fields = self.fields_for_type(name);
if !fields.is_empty() {
for (_, field_ty) in fields {
if !self.is_memo_safe(&field_ty, visiting) {
return false;
}
}
return true;
}
// Check sum type variants: constructors are registered as
// "TypeName.VariantName" with param types, or in value_members
// for zero-arg constructors. Phase B: constructors live in
// `extra_sigs`, never in the FnId-keyed `fn_sigs`, but
// `all_fn_sigs` flattens both halves for the prefix scan.
let prefix = format!("{}.", name);
let mut found_variants = false;
for (key, sig) in self.all_fn_sigs() {
if key.starts_with(&prefix) && key.len() > prefix.len() {
found_variants = true;
for param in &sig.params {
if !self.is_memo_safe(param, visiting) {
return false;
}
}
}
}
for key in self.value_members.keys() {
if key.starts_with(&prefix) && key.len() > prefix.len() {
found_variants = true;
// Zero-arg constructors carry no data — always safe
}
}
if found_variants {
return true;
}
// Unknown named type — conservatively not safe
false
}
/// Compute the set of user-defined type names that are memo-safe.
pub(super) fn compute_memo_safe_types(&self, items: &[TopLevel]) -> HashSet<String> {
let mut safe = HashSet::new();
for item in items {
if let TopLevel::TypeDef(td) = item {
let name = match td {
TypeDef::Sum { name, .. } | TypeDef::Product { name, .. } => name,
};
let mut visiting = HashSet::new();
if self.is_memo_safe(&Type::named(name.clone()), &mut visiting) {
safe.insert(name.clone());
}
}
}
safe
}
}