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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_eval_driver_hpp
#define tuscany_eval_driver_hpp
/**
* Script evaluator main driver loop.
*/
#include <string>
#include <iostream>
#include "eval.hpp"
namespace tuscany {
namespace eval {
const std::string evalOutputPrompt("; ");
const std::string evalInputPrompt("=> ");
const bool promptForInput(std::ostream& out, const std::string str) {
out << "\n\n" << str;
return true;
}
const bool announceOutput(std::ostream& out, const std::string str) {
out << "\n" << str;
return true;
}
const bool userPrint(std::ostream& out, const value object) {
if(isCompoundProcedure(object))
out << mklist<value>(compoundProcedureSymbol, procedureParameters(object), procedureBody(object), "<procedure-env>");
out << object;
return true;
}
const value evalDriverLoop(std::istream& in, std::ostream& out, Env& globalEnv, const gc_pool& pool) {
promptForInput(out, evalInputPrompt);
value input = read(in);
if (isNil(input))
return input;
const value output = evalExpr(input, globalEnv, pool);
announceOutput(out, evalOutputPrompt);
userPrint(out, output);
return evalDriverLoop(in, out, globalEnv, pool);
}
const bool evalDriverRun(std::istream& in, std::ostream& out) {
gc_pool pool;
setupEvalOut(out);
Env globalEnv = setupEnvironment(pool);
evalDriverLoop(in, out, globalEnv, pool);
cleanupEnvironment(globalEnv);
return true;
}
}
}
#endif /* tuscany_eval_driver_hpp */
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