Fix missing fields not warning in structs

README.md

@@ -53,7 +53,7 @@ Currently missing big features (TODOs) are:
 - Importable binops?
 
 Big features that I want later but are not necessary:
-- Associated functions
+- Associated functions (for e.g. sizeof)
 - ~~User-defined binary operations~~ (DONE)
 - ~~Asymmetric binary operations (e.g. string + u32)~~ (DONE)
 - Error handling

examples/struct.reid

@@ -7,11 +7,10 @@ struct Test {
 
 fn main() -> u32 {
     let mut value = Test {
-        field: 5,
         second: 3,
+        field: 5,
     };
 
-    value.second = 17;
 
     return value.second;
 }

reid/src/mir/typecheck/mod.rs

@@ -50,6 +50,8 @@ pub enum ErrorKind {
     TriedAccessingNonStruct(TypeKind),
     #[error("No such struct-field on type {0}")]
     NoSuchField(String),
+    #[error("Missing definition for field \"{0}\"")]
+    MissingStructField(String),
     #[error("Struct field declared twice {0}")]
     DuplicateStructField(String),
     #[error("Type declared twice {0}")]

reid/src/mir/typecheck/typecheck.rs

@@ -632,6 +632,13 @@ impl Expression {
                     .get_struct_type(&type_key)
                     .ok_or(ErrorKind::NoSuchType(struct_name.clone(), type_key.1))?
                     .clone();
+
+                let mut expected_fields = if let Some(struct_ty) = state.scope.get_struct_type(&type_key) {
+                    struct_ty.0.iter().map(|f| f.0.clone()).collect()
+                } else {
+                    HashSet::new()
+                };
+
                 for (field_name, field_expr) in items {
                     // Get expected type, or error if field does not exist
                     let expected_ty = state.or_else(
@@ -641,6 +648,7 @@ impl Expression {
                         &TypeKind::Vague(VagueType::Unknown),
                         field_expr.1,
                     );
+                    expected_fields.remove(field_name);
 
                     // Typecheck the actual expression
                     let expr_res = field_expr.typecheck(state, typerefs, HintKind::Coerce(expected_ty.clone()));
@@ -649,6 +657,15 @@ impl Expression {
                     // Make sure both are the same type, report error if not
                     state.ok(expr_ty.narrow_into(&expr_ty), field_expr.1);
                 }
+
+                state.note_errors(
+                    &expected_fields
+                        .into_iter()
+                        .map(|v| ErrorKind::MissingStructField(v))
+                        .collect(),
+                    self.1,
+                );
+
                 Ok(TypeKind::CustomType(type_key))
             }
             ExprKind::Borrow(var_ref, mutable) => {