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Diffstat (limited to '')
-rw-r--r-- | sca-cpp/branches/gcc-4.4/modules/scheme/driver.hpp | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sca-cpp/branches/gcc-4.4/modules/scheme/driver.hpp b/sca-cpp/branches/gcc-4.4/modules/scheme/driver.hpp new file mode 100644 index 0000000000..112c226ed1 --- /dev/null +++ b/sca-cpp/branches/gcc-4.4/modules/scheme/driver.hpp @@ -0,0 +1,76 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/* $Rev$ $Date$ */ + +#ifndef tuscany_scheme_driver_hpp +#define tuscany_scheme_driver_hpp + +/** + * Script evaluator main driver loop. + */ + +#include "string.hpp" +#include "stream.hpp" +#include "eval.hpp" + +namespace tuscany { +namespace scheme { + +const string evalOutputPrompt("; "); +const string evalInputPrompt("=> "); + +const bool promptForInput(const string& str, ostream& out) { + out << endl << endl << str; + return true; +} + +const bool announceOutput(const string str, ostream& out) { + out << endl << str; + return true; +} + +const bool userPrint(const value val, ostream& out) { + if(isCompoundProcedure(val)) + writeValue(mklist<value>(compoundProcedureSymbol, procedureParameters(val), procedureBody(val), "<procedure-env>"), out); + writeValue(val, out); + return true; +} + +const value evalDriverLoop(istream& in, ostream& out, Env& env) { + promptForInput(evalInputPrompt, out); + value input = readValue(in); + if (isNil(input)) + return input; + const value output = evalExpr(input, env); + announceOutput(evalOutputPrompt, out); + userPrint(output, out); + return evalDriverLoop(in, out, env); +} + +const bool evalDriverRun(istream& in, ostream& out) { + setupDisplay(out); + Env env = setupEnvironment(); + evalDriverLoop(in, out, env); + return true; +} + +} +} +#endif /* tuscany_scheme_driver_hpp */ |