Merge pull request #118 from wrbl606/add_++_--_prefix_support

Add `++i` and `--i` support
ethanblake4 · Oct 19, 2023 · 3558bac · 3558bac
2 parents 1169c6b + 22386d8
commit 3558bac
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Showing 4 changed files with 207 additions and 21 deletions.
diff --git a/lib/src/eval/compiler/expression/postfix.dart b/lib/src/eval/compiler/expression/postfix.dart
@@ -8,22 +8,24 @@ import 'package:dart_eval/src/eval/runtime/runtime.dart';
 
 Variable compilePostfixExpression(PostfixExpression e, CompilerContext ctx) {
   final V = compileExpressionAsReference(e.operand, ctx);
-  var L = V.getValue(ctx);
+  final L = V.getValue(ctx);
   var out = L;
 
-  if (L.name != null) {
-    out = Variable.alloc(ctx, L.type);
-    ctx.pushOp(PushNull.make(), PushNull.LEN);
-    ctx.pushOp(CopyValue.make(out.scopeFrameOffset, L.scopeFrameOffset),
-        CopyValue.LEN);
-  }
+  out = Variable.alloc(ctx, L.type);
+  ctx.pushOp(PushNull.make(), PushNull.LEN);
+  ctx.pushOp(
+      CopyValue.make(out.scopeFrameOffset, L.scopeFrameOffset), CopyValue.LEN);
 
-  final opMap = {TokenType.PLUS_PLUS: '+', TokenType.MINUS_MINUS: '-'};
+  const opMap = {TokenType.PLUS_PLUS: '+', TokenType.MINUS_MINUS: '-'};
 
   V.setValue(
+    ctx,
+    L.invoke(
       ctx,
-      L.invoke(ctx, opMap[e.operator.type]!,
-          [BuiltinValue(intval: 1).push(ctx)]).result);
+      opMap[e.operator.type]!,
+      [BuiltinValue(intval: 1).push(ctx)],
+    ).result,
+  );
 
   return out;
 }
diff --git a/lib/src/eval/compiler/expression/prefix.dart b/lib/src/eval/compiler/expression/prefix.dart
@@ -3,23 +3,33 @@ import 'package:analyzer/dart/ast/token.dart';
 import 'package:dart_eval/dart_eval_bridge.dart';
 import 'package:dart_eval/src/eval/compiler/builtins.dart';
 import 'package:dart_eval/src/eval/compiler/context.dart';
+import 'package:dart_eval/src/eval/compiler/reference.dart';
 import 'package:dart_eval/src/eval/compiler/type.dart';
 import 'package:dart_eval/src/eval/compiler/variable.dart';
+import 'package:dart_eval/src/eval/runtime/runtime.dart';
 
 import '../errors.dart';
 import 'expression.dart';
 
+const _opMap = {
+  TokenType.MINUS: '-',
+  TokenType.BANG: '!',
+  TokenType.PLUS_PLUS: '+',
+  TokenType.MINUS_MINUS: '-',
+};
+
 /// Compile a [PrefixExpression] to EVC bytecode
 Variable compilePrefixExpression(CompilerContext ctx, PrefixExpression e) {
-  var V = compileExpression(e.operand, ctx);
+  final method = _opMap[e.operator.type] ??
+      (throw CompileError('Unknown unary operator ${e.operator.type}'));
 
-  final opMap = {
-    TokenType.MINUS: '-',
-    TokenType.BANG: '!',
-  };
+  if ([TokenType.PLUS_PLUS, TokenType.MINUS_MINUS].contains(e.operator.type)) {
+    final V = compileExpressionAsReference(e.operand, ctx);
+    final L = V.getValue(ctx);
+    return _handleDoubleOperands(e, ctx, V, L);
+  }
 
-  var method = opMap[e.operator.type] ??
-      (throw CompileError('Unknown unary operator ${e.operator.type}'));
+  final V = compileExpression(e.operand, ctx);
 
   if (method == '-' &&
       V.type != CoreTypes.int.ref(ctx) &&
@@ -34,8 +44,40 @@ Variable compilePrefixExpression(CompilerContext ctx, PrefixExpression e) {
   if (method == "!") {
     return V.invoke(ctx, method, []).result;
   }
-  final zero = V.type == CoreTypes.int.ref(ctx)
-      ? BuiltinValue(intval: 0)
-      : BuiltinValue(doubleval: 0.0);
-  return zero.push(ctx).invoke(ctx, method, [V]).result;
+
+  return _zeroForType(V.type, ctx).push(ctx).invoke(ctx, method, [V]).result;
+}
+
+BuiltinValue _zeroForType(TypeRef type, CompilerContext ctx) =>
+    type == CoreTypes.int.ref(ctx)
+        ? BuiltinValue(intval: 0)
+        : BuiltinValue(doubleval: 0.0);
+
+BuiltinValue _oneForType(TypeRef type, CompilerContext ctx) =>
+    type == CoreTypes.int.ref(ctx)
+        ? BuiltinValue(intval: 1)
+        : BuiltinValue(doubleval: 1.0);
+
+Variable _handleDoubleOperands(
+  PrefixExpression e,
+  CompilerContext ctx,
+  Reference V,
+  Variable L,
+) {
+  var l = L;
+
+  l = Variable.alloc(ctx, L.type);
+  ctx.pushOp(PushNull.make(), PushNull.LEN);
+  ctx.pushOp(
+    CopyValue.make(l.scopeFrameOffset, L.scopeFrameOffset),
+    CopyValue.LEN,
+  );
+
+  final result = l.invoke(
+    ctx,
+    _opMap[e.operator.type]!,
+    [_oneForType(l.type, ctx).push(ctx)],
+  ).result;
+
+  return V.setValue(ctx, result);
 }
diff --git a/test/postfix_test.dart b/test/postfix_test.dart
@@ -0,0 +1,71 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:test/expect.dart';
+import 'package:test/scaffolding.dart';
+
+void main() {
+  group('Postfix', () {
+    late Compiler compiler;
+
+    setUp(() {
+      compiler = Compiler();
+    });
+
+    test('i++', () {
+      final runtime = compiler.compileWriteAndLoad({
+        'eval_test': {
+          'main.dart': '''
+            void main() {
+              double d = 0.0;
+              double di = d++;
+              print(di);
+              print(d);
+              int i = 0;
+              int ii = i++;
+              print(ii);
+              print(i);
+              List<int> list = [0];
+              print(list[0]++);
+              print(list[0]);
+            }
+          '''
+        }
+      });
+
+      expect(
+        () {
+          runtime.executeLib('package:eval_test/main.dart', 'main');
+        },
+        prints('0.0\n1.0\n0\n1\n0\n1\n'),
+      );
+    });
+
+    test('i--', () {
+      final runtime = compiler.compileWriteAndLoad({
+        'eval_test': {
+          'main.dart': '''
+            void main() {
+              double d = 1.0;
+              double di = d--;
+              print(di);
+              print(d);
+              int i = 1;
+              int ii = i--;
+              print(ii);
+              print(i);
+              List<int> list = [1];
+              print(list[0]--);
+              print(list[0]);
+            }
+          '''
+        }
+      });
+
+      expect(
+        () {
+          runtime.executeLib('package:eval_test/main.dart', 'main');
+        },
+        prints('1.0\n0.0\n1\n0\n1\n0\n'),
+      );
+    });
+  });
+}
diff --git a/test/prefix_test.dart b/test/prefix_test.dart
@@ -0,0 +1,71 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:test/expect.dart';
+import 'package:test/scaffolding.dart';
+
+void main() {
+  group('Prefix', () {
+    late Compiler compiler;
+
+    setUp(() {
+      compiler = Compiler();
+    });
+
+    test('++i', () {
+      final runtime = compiler.compileWriteAndLoad({
+        'eval_test': {
+          'main.dart': '''
+            void main() {
+              double d = 0.0;
+              double di = ++d;
+              print(di);
+              print(d);
+              int i = 0;
+              int ii = ++i;
+              print(ii);
+              print(i);
+              List<int> list = [0];
+              print(++list[0]);
+              print(list[0]);
+            }
+          '''
+        }
+      });
+
+      expect(
+        () {
+          runtime.executeLib('package:eval_test/main.dart', 'main');
+        },
+        prints('1.0\n1.0\n1\n1\n1\n1\n'),
+      );
+    });
+
+    test('--i', () {
+      final runtime = compiler.compileWriteAndLoad({
+        'eval_test': {
+          'main.dart': '''
+            void main() {
+              double d = 1.0;
+              double di = --d;
+              print(di);
+              print(d);
+              int i = 1;
+              int ii = --i;
+              print(ii);
+              print(i);
+              List<int> list = [1];
+              print(--list[0]);
+              print(list[0]);
+            }
+          '''
+        }
+      });
+
+      expect(
+        () {
+          runtime.executeLib('package:eval_test/main.dart', 'main');
+        },
+        prints('0.0\n0.0\n0\n0\n0\n0\n'),
+      );
+    });
+  });
+}