added struct getters

boring/parse.py

@@ -31,9 +31,7 @@ NEVER_TYPE = "!"
 
 @dataclass
 class FunctionTypeUsage:
-    arguments: List[
-        "TypeUsage"
-    ]
+    arguments: List["TypeUsage"]
     return_type: "TypeUsage"
 
 
@@ -68,6 +66,7 @@ class LiteralFloat:
     value: float
     type: TypeUsage
 
+
 @dataclass
 class LiteralStruct:
     name: str
@@ -82,6 +81,13 @@ class FunctionCall:
     type: TypeUsage
 
 
+@dataclass
+class StructGetter:
+    source: "Expression"
+    attribute: str
+    type: TypeUsage
+
+
 @dataclass
 class Operation:
     left: "Expression"
@@ -109,6 +115,7 @@ class Expression:
         LiteralFloat,
         LiteralStruct,
         FunctionCall,
+        StructGetter,
         "Block",
         ReturnStatement,
         VariableUsage,
@@ -190,6 +197,8 @@ boring_grammar = r"""
 
     function_call : expression "(" [expression ("," expression)*] ")"
 
+    struct_getter : expression "." identifier
+
     add_expression : expression plus factor
     sub_expression : expression minus factor
     mult_expression : expression mult term
@@ -212,6 +221,7 @@ boring_grammar = r"""
          | literal_struct
          | variable_usage
          | function_call
+         | struct_getter
          | "(" expression ")"
          | block
 
@@ -317,6 +327,10 @@ class TreeToBoring(Transformer):
     def function_call(self, call) -> FunctionCall:
         return FunctionCall(source=call[0], arguments=call[1:], type=UnknownTypeUsage())
 
+    def struct_getter(self, getter) -> StructGetter:
+        expression, attribute = getter
+        return StructGetter(expression, attribute, UnknownTypeUsage())
+
     def add_expression(self, ae) -> Operation:
         return Operation(left=ae[0], op=ae[1], right=ae[2], type=UnknownTypeUsage())
 

boring/type_checking.py

@@ -28,7 +28,9 @@ def unify(ctx: Context, first, second) -> bool:
     return changed
 
 
-def type_compare(ctx: Context, first: parse.TypeUsage, second: parse.TypeUsage) -> Tuple[parse.TypeUsage, bool]:
+def type_compare(
+    ctx: Context, first: parse.TypeUsage, second: parse.TypeUsage
+) -> Tuple[parse.TypeUsage, bool]:
     print(first, second)
     if isinstance(first, parse.UnknownTypeUsage):
         if not isinstance(second, parse.UnknownTypeUsage):
@@ -84,6 +86,7 @@ def assert_exists(ctx: Context, type: parse.TypeUsage):
         for argument in type.arguments:
             assert_exists(ctx, argument)
 
+
 class TypeChecker:
     def with_module(self, ctx: Context, module: parse.Module) -> bool:
         for type_declaration in module.types:
@@ -234,6 +237,11 @@ class TypeChecker:
             if unify(ctx, subexpression, expression):
                 changed = True
             return changed
+        if isinstance(subexpression, parse.StructGetter):
+            changed = self.with_struct_getter(ctx, subexpression)
+            if unify(ctx, subexpression, expression):
+                changed = True
+            return changed
         if isinstance(subexpression, parse.Block):
             changed = self.with_block(ctx, subexpression)
             if unify(ctx, subexpression, expression):
@@ -305,6 +313,22 @@ class TypeChecker:
                 changed = True
         return changed
 
+    def with_struct_getter(
+        self, ctx: Context, struct_getter: parse.StructGetter
+    ) -> bool:
+        changed = self.with_expression(ctx, struct_getter.source)
+        assert isinstance(struct_getter.source.type, parse.DataTypeUsage)
+        struct_declaration = ctx.environment[struct_getter.source.type.name]
+        assert isinstance(struct_declaration, parse.StructTypeDeclaration)
+        assert struct_getter.attribute in struct_declaration.fields
+        result_type, changed_getter = type_compare(
+            ctx, struct_getter.type, struct_declaration.fields[struct_getter.attribute]
+        )
+        if changed_getter:
+            changed = True
+            struct_getter.type = result_type
+        return changed
+
     def with_literal_float(
         self, ctx: Context, literal_float: parse.LiteralFloat
     ) -> bool:
@@ -321,7 +345,9 @@ class TypeChecker:
             assert literal_int.type.name in ints, f"{literal_int.type}"
         return False
 
-    def with_literal_struct(self, ctx: Context, literal_struct: parse.LiteralStruct) -> bool:
+    def with_literal_struct(
+        self, ctx: Context, literal_struct: parse.LiteralStruct
+    ) -> bool:
         assert literal_struct.name in ctx.environment
         struct_declaration = ctx.environment[literal_struct.name]
         assert isinstance(struct_declaration, parse.StructTypeDeclaration)
@@ -330,7 +356,9 @@ class TypeChecker:
             assert name in literal_struct.fields
             if self.with_expression(ctx, literal_struct.fields[name]):
                 changed = True
-            result_type, field_changed = type_compare(ctx, field_type, literal_struct.fields[name].type)
+            result_type, field_changed = type_compare(
+                ctx, field_type, literal_struct.fields[name].type
+            )
             if field_changed:
                 literal_struct.fields[name].type = result_type
                 changed = True

examples/math/main.bl

@@ -28,17 +28,22 @@ fn unit_function() {
   let a: I32 = 4;
 }
 
+fn main(): I32 {
+    add(4, subtract(5, 2))
+}
+
+
 fn returns_user(): User {
     return User{
         id: 4,
     };
 }
 
-fn main(): I32 {
-    add(4, subtract(5, 2))
+fn get_user_id(): U64 {
+    let user = returns_user();
+    return user.id;
 }
 
-
 type User struct {
     id: U64,
 }

notes.txt

@@ -40,12 +40,12 @@ TODO:
 * Structs
   * ~Define~
   * ~Literal~
-  * Getter
+  * ~Getter~
   * Setter
-* Generics
-* Enums
 * Methods
 * Traits
+* Generics
+* Enums
 * Arrays
 * Strings
 * Lambdas