Index: pkg/kernel/lib/interpreter/interpreter.dart |
diff --git a/pkg/kernel/lib/interpreter/interpreter.dart b/pkg/kernel/lib/interpreter/interpreter.dart |
new file mode 100644 |
index 0000000000000000000000000000000000000000..f4f87794487782fad8e299b6762d142050ce8dcd |
--- /dev/null |
+++ b/pkg/kernel/lib/interpreter/interpreter.dart |
@@ -0,0 +1,83 @@ |
+// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file |
+// for details. All rights reserved. Use of this source code is governed by a |
+// BSD-style license that can be found in the LICENSE file. |
+library kernerl.interpreter; |
+ |
+import 'dart:collection'; |
+import '../ast.dart'; |
+ |
+class NotImplemented { |
+ String message; |
+ |
+ NotImplemented(this.message); |
+ |
+ String toString() => message; |
+} |
+ |
+class Interpreter { |
+ Program program; |
+ |
+ Interpreter(this.program); |
+ |
+ void evalProgram() { |
+ assert(program.libraries.isEmpty); |
+ Procedure mainMethod = program.mainMethod; |
+ Statement statementBlock = mainMethod.function.body; |
+ // Evaluate only statement with one expression, ExpressionStatement, which |
+ // is StaticInvocation of the method print. |
+ if (statementBlock is Block) { |
+ Statement statement = statementBlock.statements.first; |
+ if (statement is ExpressionStatement) { |
+ statement.expression.accept1(new ExpressionEval1(), |
+ new ExpressionState(new HashMap<String, Object>())); |
+ } |
+ } else { |
+ throw new NotImplemented('Evaluation for statement type ' |
+ '${statementBlock.runtimeType} is not implemented'); |
+ } |
+ } |
+} |
+ |
+class InvalidExpressionError { |
+ InvalidExpression expression; |
+ |
+ InvalidExpressionError(this.expression); |
+ |
+ String toString() => 'Invalid expression at ' |
+ '${expression.location.toString()}'; |
+} |
+ |
+class ExpressionState { |
+ Map<String, Object> environment; |
+ |
+ ExpressionState(this.environment); |
+} |
+ |
+class ExpressionEval1 extends ExpressionVisitor1<Object> { |
+ @override |
+ Object defaultExpression(Expression node, arg) { |
+ throw new NotImplemented('Evaluation for expressions of type ' |
+ '${node.runtimeType} is not implemented.'); |
+ } |
+ |
+ Object visitInvalidExpression1(InvalidExpression node, arg) => |
+ throw new InvalidExpressionError(node); |
+ |
+ Object visitStaticInvocation(StaticInvocation node, arg) { |
+ if ('print' == node.name.toString()) { |
+ // Special evaluation of print. |
+ var res = node.arguments.positional[0].accept1(this, arg); |
+ print(res); |
+ } else { |
+ throw new NotImplemented('Support for statement type ' |
+ '${node.runtimeType} is not implemented'); |
+ } |
+ } |
+ |
+ // Evaluation of BasicLiterals. |
+ Object visitStringLiteral(StringLiteral node, arg) => node.value; |
+ Object visitIntLiteral(IntLiteral node, arg) => node.value; |
+ Object visitDoubleLiteral(DoubleLiteral node, arg) => node.value; |
+ Object visitBoolLiteral(BoolLiteral node, arg) => node.value; |
+ Object visitNullLiteral(NullLiteral node, arg) => node.value; |
+} |