assignment is an expression

xffxff · Sep 25, 2023 · ed35a2f · ed35a2f
1 parent 03ff05a
commit ed35a2f
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Showing 6 changed files with 235 additions and 6 deletions.
diff --git a/components/lox-execute/src/vm.rs b/components/lox-execute/src/vm.rs
@@ -235,8 +235,8 @@ impl VM {
                     self.push(value.clone());
                 }
                 bytecode::Code::Assign(name) => {
-                    let value = self.pop();
-                    self.globals.insert(name, value);
+                    let value = self.peek();
+                    self.globals.insert(name, value.clone());
                 }
             }
             if let Some(step_inspect) = &mut step_inspect {
@@ -255,6 +255,10 @@ impl VM {
         self.stack.pop().unwrap()
     }
 
+    fn peek(&self) -> &Value {
+        self.stack.last().unwrap()
+    }
+
     fn push<T>(&mut self, value: T)
     where
         T: Into<Value>,

diff --git a/lox_tests/assignment.lox b/lox_tests/assignment.lox
@@ -1,3 +1,8 @@
 var a = 1;
 a = 2;
-print a;
+print a;
+print a = 3;
+var b = a;
+var c;
+c = b;
+print c;
diff --git a/lox_tests/assignment/bytecode b/lox_tests/assignment/bytecode
@@ -20,5 +20,34 @@ Chunk {
             "a",
         ),
         Print,
+        Constant(
+            F64(
+                3.0,
+            ),
+        ),
+        Assign(
+            "a",
+        ),
+        Print,
+        Variable(
+            "a",
+        ),
+        VarDeclaration(
+            "b",
+        ),
+        Nil,
+        VarDeclaration(
+            "c",
+        ),
+        Variable(
+            "b",
+        ),
+        Assign(
+            "c",
+        ),
+        Variable(
+            "c",
+        ),
+        Print,
     ],
 }
diff --git a/lox_tests/assignment/execute b/lox_tests/assignment/execute
@@ -28,7 +28,11 @@ stack: [
 execute: Assign(
     "a",
 )
-stack: []
+stack: [
+    Number(
+        2.0,
+    ),
+]
 
 execute: Variable(
     "a",
@@ -37,8 +41,135 @@ stack: [
     Number(
         2.0,
     ),
+    Number(
+        2.0,
+    ),
 ]
 
 execute: Print
-stack: []
+stack: [
+    Number(
+        2.0,
+    ),
+]
+
+execute: Constant(
+    F64(
+        3.0,
+    ),
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: Assign(
+    "a",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: Print
+stack: [
+    Number(
+        2.0,
+    ),
+]
+
+execute: Variable(
+    "a",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: VarDeclaration(
+    "b",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+]
+
+execute: Nil
+stack: [
+    Number(
+        2.0,
+    ),
+    Nil,
+]
+
+execute: VarDeclaration(
+    "c",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+]
+
+execute: Variable(
+    "b",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: Assign(
+    "c",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: Variable(
+    "c",
+)
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
+
+execute: Print
+stack: [
+    Number(
+        2.0,
+    ),
+    Number(
+        3.0,
+    ),
+]
 
diff --git a/lox_tests/assignment/syntax b/lox_tests/assignment/syntax
@@ -13,3 +13,28 @@ Expr {
 Print {
     expr: Variable(a),
 }
+Print {
+    expr: Assign {
+        name: "a",
+        value: NumberLiteral(3),
+    },
+}
+Var {
+    name: "b",
+    initializer: Some(
+        Variable(a),
+    ),
+}
+Var {
+    name: "c",
+    initializer: None,
+}
+Expr {
+    expr: Assign {
+        name: "c",
+        value: Variable(b),
+    },
+}
+Print {
+    expr: Variable(c),
+}
diff --git a/lox_tests/assignment/token b/lox_tests/assignment/token
@@ -1,5 +1,5 @@
 TokenTree {
-    source text: "var a = 1;\na = 2;\nprint a;",
+    source text: "var a = 1;\na = 2;\nprint a;\nprint a = 3;\nvar b = a;\nvar c;\nc = b;\nprint c;",
     tokens: [
         Alphabetic(var),
         Whitespace(' '),
@@ -21,5 +21,40 @@ TokenTree {
         Whitespace(' '),
         Alphabetic(a),
         Semicolon,
+        Whitespace('\n'),
+        Alphabetic(print),
+        Whitespace(' '),
+        Alphabetic(a),
+        Whitespace(' '),
+        Op(=),
+        Whitespace(' '),
+        Number(3),
+        Semicolon,
+        Whitespace('\n'),
+        Alphabetic(var),
+        Whitespace(' '),
+        Alphabetic(b),
+        Whitespace(' '),
+        Op(=),
+        Whitespace(' '),
+        Alphabetic(a),
+        Semicolon,
+        Whitespace('\n'),
+        Alphabetic(var),
+        Whitespace(' '),
+        Alphabetic(c),
+        Semicolon,
+        Whitespace('\n'),
+        Alphabetic(c),
+        Whitespace(' '),
+        Op(=),
+        Whitespace(' '),
+        Alphabetic(b),
+        Semicolon,
+        Whitespace('\n'),
+        Alphabetic(print),
+        Whitespace(' '),
+        Alphabetic(c),
+        Semicolon,
     ],
 }