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/*
* 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 */
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