Refine type error reporting for readability

The `display_compact` method on `StaticType` has been enhanced to
provide more concise representations of types within error messages.
This change aims to improve the clarity of type-related diagnostics
generated by the compiler.

src/ast/compiler/type_checker.rs

@@ -307,7 +307,7 @@ impl TypeChecker {
             (a, b) if a == b => {}
             (StaticType::TypeVar(n), ty) | (ty, StaticType::TypeVar(n)) => {
                 if Self::occurs(n, &ty, &subst) {
-                    diag.push_error(format!("Infinite type: ?{} = {}", n, ty), None);
+                    diag.push_error(format!("Infinite type: ?{} = {}", n, ty.display_compact()), None);
                     return;
                 }
                 // Release the borrow before routing through bind_var so that
@@ -369,7 +369,7 @@ impl TypeChecker {
                 self.unify(*body, other, diag);
             }
             (a, b) => {
-                diag.push_error(format!("Type mismatch: expected {}, got {}", a, b), None);
+                diag.push_error(format!("Type mismatch: expected {}, got {}", a.display_compact(), b.display_compact()), None);
             }
         }
     }
@@ -1000,7 +1000,7 @@ impl TypeChecker {
                 diag.push_error(
                     format!(
                         "Cannot destructure type {} as a tuple/vector",
-                        specialized_ty
+                        specialized_ty.display_compact()
                     ),
                     Some(node.identity.clone()),
                 );
@@ -1194,7 +1194,7 @@ impl TypeChecker {
                             format!(
                                 "Cannot access field :{} on non-record type {}",
                                 field.name(),
-                                rec_typed.ty
+                                rec_typed.ty.display_compact()
                             ),
                             Some(rec_typed.identity.clone()),
                         );
@@ -1519,7 +1519,7 @@ impl TypeChecker {
                     diag.push_error(
                         format!(
                             "Type mismatch in 'again' call: expected {}, but got {}",
-                            expected_ty, args_typed.ty
+                            expected_ty.display_compact(), args_typed.ty.display_compact()
                         ),
                         Some(node.identity.clone()),
                     );

src/ast/types.rs

@@ -498,7 +498,7 @@ impl StaticType {
     /// Abbreviates verbose types like records to keep diagnostics readable.
     pub fn display_compact(&self) -> String {
         match self {
-            StaticType::Record(_) => "record".to_string(),
+            StaticType::Record(_) => "<record>".to_string(),
             StaticType::Tuple(elements) => {
                 let inner: Vec<String> = elements.iter().map(|e| e.display_compact()).collect();
                 format!("[{}]", inner.join(" "))