fix: array type inffering

crates/erg_common/macros.rs

@@ -503,6 +503,14 @@ macro_rules! log {
         }
     }};
 
+    (caller) => {{
+        if cfg!(feature = "debug") {
+            use $crate::style::*;
+            $crate::debug_info!();
+            println!("\n{}", std::panic::Location::caller());
+        }
+    }};
+
     ($($arg: tt)*) => {{
         if cfg!(feature = "debug") {
             use $crate::style::*;

crates/erg_compiler/context/eval.rs

@@ -23,7 +23,7 @@ use crate::ty::constructors::{
     array_t, bounded, dict_t, mono, mono_q, named_free_var, poly, proj, proj_call, ref_, ref_mut,
     refinement, set_t, subr_t, subtypeof, tp_enum, tuple_t, unknown_len_array_t, v_enum,
 };
-use crate::ty::free::{Constraint, HasLevel};
+use crate::ty::free::HasLevel;
 use crate::ty::typaram::{OpKind, TyParam};
 use crate::ty::value::{GenTypeObj, TypeObj, ValueObj};
 use crate::ty::{
@@ -1561,9 +1561,9 @@ impl Context {
                 } else {
                     self.eval_t_params(sup, level, t_loc)?
                 };
-                let new_constraint = Constraint::new_sandwiched(sub, sup);
-                fv.update_constraint(new_constraint, false);
-                Ok(Type::FreeVar(fv))
+                let fv = Type::FreeVar(fv);
+                fv.update_tyvar(sub, sup, None, false);
+                Ok(fv)
             }
             Type::Subr(mut subr) => {
                 for pt in subr.non_default_params.iter_mut() {

crates/erg_compiler/lower.rs

@@ -353,30 +353,7 @@ impl ASTLowerer {
         for elem in elems.into_iter() {
             let elem = self.lower_expr(elem.expr, expect_elem.as_ref())?;
             let union_ = self.module.context.union(&union, elem.ref_t());
-            if let Some((l, r)) = union_.union_pair() {
-                match (l.is_unbound_var(), r.is_unbound_var()) {
-                    // e.g. [1, "a"]
-                    (false, false) => {
-                        if let hir::Expr::TypeAsc(type_asc) = &elem {
-                            // e.g. [1, "a": Str or NoneType]
-                            if ERG_MODE
-                                && !self
-                                    .module
-                                    .context
-                                    .supertype_of(&type_asc.spec.spec_t, &union)
-                            {
-                                return Err(self.elem_err(&l, &r, &elem));
-                            } // else(OK): e.g. [1, "a": Str or Int]
-                        } else if ERG_MODE {
-                            return Err(self.elem_err(&l, &r, &elem));
-                        }
-                    }
-                    // TODO: check if the type is compatible with the other type
-                    (true, false) => {}
-                    (false, true) => {}
-                    (true, true) => {}
-                }
-            }
+            self.homogeneity_check(expect_elem.as_ref(), &union_, &union, &elem)?;
             union = union_;
             new_array.push(elem);
         }
@@ -398,6 +375,41 @@ impl ASTLowerer {
         Ok(hir::NormalArray::new(array.l_sqbr, array.r_sqbr, t, elems))
     }
 
+    fn homogeneity_check(
+        &self,
+        expect_elem: Option<&Type>,
+        union_: &Type,
+        union: &Type,
+        elem: &hir::Expr,
+    ) -> LowerResult<()> {
+        if ERG_MODE && expect_elem.is_none() {
+            if let Some((l, r)) = union_.union_pair() {
+                match (l.is_unbound_var(), r.is_unbound_var()) {
+                    // e.g. [1, "a"]
+                    (false, false) => {
+                        if let hir::Expr::TypeAsc(type_asc) = elem {
+                            // e.g. [1, "a": Str or NoneType]
+                            if !self
+                                .module
+                                .context
+                                .supertype_of(&type_asc.spec.spec_t, union)
+                            {
+                                return Err(self.elem_err(&l, &r, elem));
+                            } // else(OK): e.g. [1, "a": Str or Int]
+                        } else {
+                            return Err(self.elem_err(&l, &r, elem));
+                        }
+                    }
+                    // TODO: check if the type is compatible with the other type
+                    (true, false) => {}
+                    (false, true) => {}
+                    (true, true) => {}
+                }
+            }
+        }
+        Ok(())
+    }
+
     fn lower_array_with_length(
         &mut self,
         array: ast::ArrayWithLength,
@@ -1731,23 +1743,24 @@ impl ASTLowerer {
         if let Err(errs) = self.module.context.register_const(&body.block) {
             self.errs.extend(errs);
         }
-        match self.lower_block(body.block, None) {
+        let outer = self.module.context.outer.as_ref().unwrap();
+        let expect_body_t = sig
+            .t_spec
+            .as_ref()
+            .and_then(|t_spec| {
+                self.module
+                    .context
+                    .instantiate_var_sig_t(Some(&t_spec.t_spec), RegistrationMode::PreRegister)
+                    .ok()
+            })
+            .or_else(|| {
+                sig.ident()
+                    .and_then(|ident| outer.get_current_scope_var(&ident.name))
+                    .map(|vi| vi.t.clone())
+            });
+        match self.lower_block(body.block, expect_body_t.as_ref()) {
             Ok(block) => {
                 let found_body_t = block.ref_t();
-                let outer = self.module.context.outer.as_ref().unwrap();
-                let opt_expect_body_t = self
-                    .module
-                    .context
-                    .instantiate_var_sig_t(
-                        sig.t_spec.as_ref().map(|ts| &ts.t_spec),
-                        RegistrationMode::PreRegister,
-                    )
-                    .ok()
-                    .or_else(|| {
-                        sig.ident()
-                            .and_then(|ident| outer.get_current_scope_var(&ident.name))
-                            .map(|vi| vi.t.clone())
-                    });
                 let ident = match &sig.pat {
                     ast::VarPattern::Ident(ident) => ident.clone(),
                     ast::VarPattern::Discard(token) => {
@@ -1755,7 +1768,7 @@ impl ASTLowerer {
                     }
                     _ => unreachable!(),
                 };
-                if let Some(expect_body_t) = opt_expect_body_t {
+                if let Some(expect_body_t) = expect_body_t {
                     // TODO: expect_body_t is smaller for constants
                     // TODO: 定数の場合、expect_body_tのほうが小さくなってしまう
                     if !sig.is_const() {

crates/erg_compiler/ty/free.rs

@@ -6,7 +6,7 @@ use std::sync::atomic::AtomicUsize;
 
 use erg_common::shared::Forkable;
 use erg_common::traits::{LimitedDisplay, StructuralEq};
-use erg_common::Str;
+use erg_common::{addr, Str};
 use erg_common::{addr_eq, log};
 
 use super::typaram::TyParam;
@@ -556,7 +556,9 @@ impl Hash for Free<TyParam> {
         if let Some(lev) = self.level() {
             lev.hash(state);
         }
-        if let Some(t) = self.get_type() {
+        if self.is_recursive() {
+            addr!(self).hash(state);
+        } else if let Some(t) = self.get_type() {
             t.hash(state);
         } else if self.is_linked() {
             self.crack().hash(state);
@@ -691,6 +693,39 @@ impl Free<TyParam> {
             self.constraint().unwrap(),
         )
     }
+
+    pub fn is_recursive(&self) -> bool {
+        TyParam::FreeVar(self.clone()).is_recursive()
+    }
+
+    fn _do_avoiding_recursion<O, F: FnOnce() -> O>(
+        &self,
+        placeholder: Option<&TyParam>,
+        f: F,
+    ) -> O {
+        let placeholder = placeholder.unwrap_or(&TyParam::Failure);
+        let is_recursive = self.is_recursive();
+        if is_recursive {
+            self.undoable_link(placeholder);
+        }
+        let res = f();
+        if is_recursive {
+            self.undo();
+        }
+        res
+    }
+
+    pub fn do_avoiding_recursion<O, F: FnOnce() -> O>(&self, f: F) -> O {
+        self._do_avoiding_recursion(None, f)
+    }
+
+    pub fn do_avoiding_recursion_with<O, F: FnOnce() -> O>(
+        &self,
+        placeholder: &TyParam,
+        f: F,
+    ) -> O {
+        self._do_avoiding_recursion(Some(placeholder), f)
+    }
 }
 
 impl<T: StructuralEq + CanbeFree + Clone + Default + fmt::Debug + Send + Sync + 'static>

crates/erg_compiler/ty/mod.rs

@@ -1939,6 +1939,14 @@ impl Type {
         }
     }
 
+    pub fn is_projection(&self) -> bool {
+        match self {
+            Self::FreeVar(fv) if fv.is_linked() => fv.crack().is_projection(),
+            Self::Proj { .. } | Self::ProjCall { .. } => true,
+            _ => false,
+        }
+    }
+
     pub fn is_intersection_type(&self) -> bool {
         match self {
             Self::FreeVar(fv) if fv.is_linked() => fv.crack().is_intersection_type(),
@@ -2286,10 +2294,9 @@ impl Type {
     pub fn is_recursive(&self) -> bool {
         match self {
             Self::FreeVar(fv) if fv.is_linked() => fv.crack().is_recursive(),
-            Self::FreeVar(fv) => fv
-                .get_subsup()
-                .map(|(sub, sup)| sub.contains_type(self) || sup.contains_type(self))
-                .unwrap_or(false),
+            Self::FreeVar(fv) => fv.get_subsup().map_or(false, |(sub, sup)| {
+                sub.contains_type(self) || sup.contains_type(self)
+            }),
             Self::Record(rec) => rec.iter().any(|(_, t)| t.contains_type(self)),
             Self::NamedTuple(rec) => rec.iter().any(|(_, t)| t.contains_type(self)),
             Self::Poly { params, .. } => params.iter().any(|tp| tp.contains_type(self)),

crates/erg_compiler/ty/typaram.rs

@@ -1249,6 +1249,33 @@ impl TyParam {
         }
     }
 
+    pub fn is_recursive(&self) -> bool {
+        match self {
+            Self::FreeVar(fv) if fv.is_linked() => fv.crack().is_recursive(),
+            Self::FreeVar(fv) => fv.get_type().map_or(false, |t| t.contains_tp(self)),
+            Self::Proj { obj, .. } => obj.contains_tp(self),
+            Self::ProjCall { obj, args, .. } => {
+                obj.contains_tp(self) || args.iter().any(|t| t.contains_tp(self))
+            }
+            Self::BinOp { lhs, rhs, .. } => lhs.contains_tp(self) || rhs.contains_tp(self),
+            Self::UnaryOp { val, .. } => val.contains_tp(self),
+            Self::App { args, .. } => args.iter().any(|t| t.contains_tp(self)),
+            Self::Lambda(lambda) => lambda.body.iter().any(|t| t.contains_tp(self)),
+            Self::Array(ts) | Self::Tuple(ts) => ts.iter().any(|t| t.contains_tp(self)),
+            Self::UnsizedArray(elem) => elem.contains_tp(self),
+            Self::Set(ts) => ts.iter().any(|t| t.contains_tp(self)),
+            Self::Record(rec) => rec.iter().any(|(_, t)| t.contains_tp(self)),
+            Self::Dict(ts) => ts
+                .iter()
+                .any(|(k, v)| k.contains_tp(self) || v.contains_tp(self)),
+            Self::DataClass { fields, .. } => fields.iter().any(|(_, t)| t.contains_tp(self)),
+            Self::Type(t) => t.contains_tp(self),
+            Self::Value(ValueObj::Type(t)) => t.typ().contains_tp(self),
+            Self::Erased(t) => t.contains_tp(self),
+            _ => false,
+        }
+    }
+
     pub fn is_unbound_var(&self) -> bool {
         match self {
             Self::FreeVar(fv) => fv.is_unbound() || fv.crack().is_unbound_var(),

tests/should_ok/advanced_type_spec.er

@@ -14,4 +14,5 @@ g2: (|T|(_: Structural { .a = (self: T) -> Obj }) -> NoneType) = f2
 _, _ = f2, g2
 
 Packages = [{ .name = Str; .version = Str }; _]
-_: Packages = [{ .name = "a"; .version = "b" }]
+_: Packages = [{ .name = "a"; .version = "1.0.0" }]
+_: Packages = [{ .name = "a"; .version = "1.0.0" }, { .name = "b"; .version = "1.0.0" }]