feat: add list subscript set

examples/basic/24_list.peb

@@ -4,4 +4,21 @@ let a = [
     "c"
 ]
 print(a)
-print(a[0])
+print(a[0])
+
+a[1] = "B"
+
+print(a)
+
+let l = [
+    ["a", "b", "c"],
+    ["1", "2", "3"]
+]
+
+print(l)
+print(l[1][2])
+
+l[1][2] = "three"
+
+print(l)
+print(l[1][2])

src/ast/expr.py

@@ -74,6 +74,10 @@ class Expr(ABC):
         def visit_set_expr(self, expr: SetExpr) -> T:
             ...
 
+        @abstractmethod
+        def visit_subscript_set_expr(self, expr: SubscriptSetExpr) -> T:
+            ...
+
         @abstractmethod
         def visit_this_expr(self, expr: ThisExpr) -> T:
             ...
@@ -133,8 +137,8 @@ class GetExpr(Expr):
 @dataclass(frozen=True)
 class SubscriptGetExpr(Expr):
     object: Expr
-    bracket: Token
     index: Expr
+    bracket: Token
 
     def accept(self, visitor: Expr.Visitor[T]) -> T:
         return visitor.visit_subscript_get_expr(self)
@@ -214,6 +218,17 @@ class SetExpr(Expr):
         return visitor.visit_set_expr(self)
 
 
+@dataclass(frozen=True)
+class SubscriptSetExpr(Expr):
+    object: Expr
+    index: Expr
+    bracket: Token
+    value: Expr
+
+    def accept(self, visitor: Expr.Visitor[T]) -> T:
+        return visitor.visit_subscript_set_expr(self)
+
+
 @dataclass(frozen=True)
 class ThisExpr(Expr):
     keyword: Token

src/core/format_spec/string_formatter.py

@@ -21,7 +21,7 @@ class StringFormatter:
             return str(obj)
         if isinstance(obj, str) and quote_str:
             return '"' + obj + '"'
-        return obj
+        return str(obj)
 
     @staticmethod
     def assert_type(token: Token, obj: Any, expected_type: type | tuple[type, ...]):

src/formatter.py

@@ -2,7 +2,8 @@ from enum import Enum, auto
 from typing import Any
 
 from src.ast.expr import Expr, VariableExpr, LiteralExpr, GroupingExpr, UnaryExpr, BinaryExpr, AssignExpr, LogicalExpr, \
-    CallExpr, SetExpr, GetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr
+    CallExpr, SetExpr, GetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr, \
+    SubscriptSetExpr
 from src.ast.stmt import Stmt, LetStmt, IfStmt, ExpressionStmt, BlockStmt, WhileStmt, ForStmt, FunctionStmt, \
     ReturnStmt, BreakStmt, ContinueStmt, ClassStmt
 from src.core.format_spec.spec import FormatSpec
@@ -44,6 +45,9 @@ class Formatter(Expr.Visitor[str], Stmt.Visitor[str]):
     def visit_set_expr(self, expr: SetExpr) -> str:
         return f"{self.format(expr.object)}.{expr.name.lexeme} = {self.format(expr.value)}"
 
+    def visit_subscript_set_expr(self, expr: SubscriptSetExpr) -> str:
+        return f"{self.format(expr.object)}[{self.format(expr.index)}] = {self.format(expr.value)}"
+
     def visit_this_expr(self, expr: ThisExpr) -> str:
         return expr.keyword.lexeme
 

src/interpreter/interpreter.py

@@ -1,7 +1,8 @@
 from typing import Any, Optional
 
 from src.ast.expr import LiteralExpr, GroupingExpr, UnaryExpr, BinaryExpr, Expr, VariableExpr, AssignExpr, LogicalExpr, \
-    CallExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr
+    CallExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr, \
+    SubscriptSetExpr
 from src.ast.stmt import Stmt, ExpressionStmt, LetStmt, BlockStmt, IfStmt, WhileStmt, ForStmt, FunctionStmt, \
     ReturnStmt, BreakStmt, ContinueStmt, ClassStmt
 from src.consts import CONSTRUCTOR_NAME
@@ -90,6 +91,14 @@ class Interpreter(Expr.Visitor[Any], Stmt.Visitor[None]):
         obj.set(expr.name, value)
         return value
 
+    def visit_subscript_set_expr(self, expr: SubscriptSetExpr) -> Any:
+        obj: Any = self.evaluate(expr.object)
+        if not isinstance(obj, PebbleList):
+            raise PebbleRuntimeError(expr.bracket, "Only lists can be indexed.")
+        value: Any = self.evaluate(expr.value)
+        idx: Any = self.evaluate(expr.index)
+        obj.set(idx, value, expr.bracket)
+
     def visit_this_expr(self, expr: ThisExpr) -> Any:
         return self.look_up_variable(expr.keyword, expr)
 
@@ -177,10 +186,10 @@ class Interpreter(Expr.Visitor[Any], Stmt.Visitor[None]):
 
     def visit_subscript_get_expr(self, expr: SubscriptGetExpr) -> Any:
         obj: Any = self.evaluate(expr.object)
+        if not isinstance(obj, PebbleList):
+            raise PebbleRuntimeError(expr.bracket, "Only lists can be indexed.")
         idx: Any = self.evaluate(expr.index)
-        if isinstance(obj, PebbleList):
-            return obj.get(idx, expr.bracket)
-        raise PebbleRuntimeError(expr.bracket, "Only lists can be indexed.")
+        return obj.get(idx, expr.bracket)
 
     def visit_grouping_expr(self, expr: GroupingExpr) -> Any:
         return self.evaluate(expr.expression)

src/interpreter/resolver.py

@@ -4,7 +4,8 @@ from enum import Enum, auto
 from typing import TYPE_CHECKING
 
 from src.ast.expr import Expr, LogicalExpr, VariableExpr, LiteralExpr, GroupingExpr, CallExpr, UnaryExpr, BinaryExpr, \
-    AssignExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr
+    AssignExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr, \
+    SubscriptSetExpr
 from src.ast.stmt import Stmt, ForStmt, WhileStmt, LetStmt, ReturnStmt, IfStmt, FunctionStmt, \
     ExpressionStmt, BlockStmt, BreakStmt, ContinueStmt, ClassStmt
 from src.consts import CONSTRUCTOR_NAME
@@ -134,6 +135,11 @@ class Resolver(Expr.Visitor[None], Stmt.Visitor[None]):
         self.resolve(expr.value)
         self.resolve(expr.object)
 
+    def visit_subscript_set_expr(self, expr: SubscriptSetExpr) -> None:
+        self.resolve(expr.value)
+        self.resolve(expr.object)
+        self.resolve(expr.index)
+
     def visit_this_expr(self, expr: ThisExpr) -> None:
         if self.current_class == ClassType.NONE:
             Pebble.token_error(expr.keyword, "Cannot use 'this' outside of a class.")

src/parser/parser.py

@@ -1,7 +1,8 @@
 from typing import Optional
 
 from src.ast.expr import Expr, BinaryExpr, UnaryExpr, LiteralExpr, GroupingExpr, VariableExpr, AssignExpr, LogicalExpr, \
-    CallExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr
+    CallExpr, GetExpr, SetExpr, ThisExpr, SuperExpr, FStringExpr, FStringEmbedExpr, ListExpr, SubscriptGetExpr, \
+    SubscriptSetExpr
 from src.ast.stmt import Stmt, ExpressionStmt, LetStmt, BlockStmt, IfStmt, WhileStmt, ForStmt, FunctionStmt, \
     ReturnStmt, BreakStmt, ContinueStmt, ClassStmt
 from src.consts import MAX_FUNCTION_ARGS
@@ -275,6 +276,9 @@ class Parser:
 
             elif isinstance(expr, GetExpr):
                 return SetExpr(expr.object, expr.name, value)
+
+            elif isinstance(expr, SubscriptGetExpr):
+                return SubscriptSetExpr(expr.object, expr.index, expr.bracket, value)
             self.error(operator, "Invalid assignment target.")
         return expr
 
@@ -363,7 +367,7 @@ class Parser:
         while self.match(TokenType.LEFT_BRACKET):
             idx: Expr = self.expression()
             bracket: Token = self.consume(TokenType.RIGHT_BRACKET, "Unclosed list index")
-            expr = SubscriptGetExpr(expr, bracket, idx)
+            expr = SubscriptGetExpr(expr, idx, bracket)
         return expr
 
     def primary(self) -> Expr: