refactor(ast): move expression visitor class inside Expr

src/ast/expr.py

@@ -16,23 +16,22 @@ class Expr(ABC):
     def accept(self, visitor: Visitor[T]) -> T:
         ...
 
+    class Visitor(ABC, Generic[T]):
+        @abstractmethod
+        def visit_binary_expr(self, expr: BinaryExpr) -> T:
+            ...
 
-class Visitor(ABC, Generic[T]):
+        @abstractmethod
-    @abstractmethod
+        def visit_unary_expr(self, expr: UnaryExpr) -> T:
-    def visit_binary_expr(self, expr: BinaryExpr) -> T:
+            ...
-        ...
 
-    @abstractmethod
+        @abstractmethod
-    def visit_unary_expr(self, expr: UnaryExpr) -> T:
+        def visit_grouping_expr(self, expr: GroupingExpr) -> T:
-        ...
+            ...
 
-    @abstractmethod
+        @abstractmethod
-    def visit_grouping_expr(self, expr: GroupingExpr) -> T:
+        def visit_literal_expr(self, expr: LiteralExpr) -> T:
-        ...
+            ...
-
-    @abstractmethod
-    def visit_literal_expr(self, expr: LiteralExpr) -> T:
-        ...
 
 
 @dataclass(frozen=True)
@@ -41,7 +40,7 @@ class BinaryExpr(Expr):
     operator: Token
     right: Expr
 
-    def accept(self, visitor: Visitor[T]) -> T:
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_binary_expr(self)
 
 
@@ -50,7 +49,7 @@ class UnaryExpr(Expr):
     operator: Token
     right: Expr
 
-    def accept(self, visitor: Visitor[T]) -> T:
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_unary_expr(self)
 
 
@@ -58,7 +57,7 @@ class UnaryExpr(Expr):
 class GroupingExpr(Expr):
     expression: Expr
 
-    def accept(self, visitor: Visitor[T]) -> T:
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_grouping_expr(self)
 
 
@@ -66,5 +65,5 @@ class GroupingExpr(Expr):
 class LiteralExpr(Expr):
     value: Any
 
-    def accept(self, visitor: Visitor[T]) -> T:
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_literal_expr(self)

src/ast/printer.py

@@ -1,7 +1,7 @@
-from src.ast.expr import Visitor, Expr, LiteralExpr, T, GroupingExpr, UnaryExpr, BinaryExpr
+from src.ast.expr import Expr, LiteralExpr, GroupingExpr, UnaryExpr, BinaryExpr
 
 
-class AstPrinter(Visitor[str]):
+class AstPrinter(Expr.Visitor[str]):
     def print(self, expr: Expr):
         return expr.accept(self)
 

src/interpreter/interpreter.py

@@ -1,12 +1,12 @@
 from typing import Any
 
-from src.ast.expr import Visitor, LiteralExpr, T, GroupingExpr, UnaryExpr, BinaryExpr, Expr
+from src.ast.expr import LiteralExpr, GroupingExpr, UnaryExpr, BinaryExpr, Expr
 from src.interpreter.error import PebbleRuntimeError
 from src.pebble import Pebble
 from src.token import TokenType, Token
 
 
-class Interpreter(Visitor[Any]):
+class Interpreter(Expr.Visitor[Any]):
     def interpret(self, expr: Expr) -> Any:
         try:
             return self.evaluate(expr)