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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_modscheme_hpp
#define tuscany_modscheme_hpp
/**
* Evaluation functions used by mod-eval to evaluate Scheme
* component implementations.
*/
#include "string.hpp"
#include "stream.hpp"
#include "function.hpp"
#include "list.hpp"
#include "value.hpp"
#include "monad.hpp"
#include "../scheme/eval.hpp"
namespace tuscany {
namespace server {
namespace modscheme {
/**
* Convert proxy lambdas to evaluator primitive procedures.
*/
const list<value> primitiveProcedures(const list<value>& l) {
if (isNil(l))
return l;
return cons<value>(mklist<value>(scheme::primitiveSymbol, car(l)), primitiveProcedures(cdr(l)));
}
/**
* Apply a Scheme component implementation function.
*/
struct applyImplementation {
const value impl;
const list<value> px;
applyImplementation(const value& impl, const list<value>& px) : impl(impl), px(scheme::quotedParameters(primitiveProcedures(px))) {
}
const value operator()(const list<value>& params) const {
const value expr = cons<value>(car(params), append(scheme::quotedParameters(cdr(params)), px));
debug(expr, "modeval::scheme::applyImplementation::input");
scheme::Env env = scheme::setupEnvironment();
const value res = scheme::evalScript(expr, impl, env);
const value val = isNil(res)? mklist<value>(value(), string("Could not evaluate expression")) : mklist<value>(res);
debug(val, "modeval::scheme::applyImplementation::result");
return val;
}
};
/**
* Evaluate a Scheme component implementation and convert it to an
* applicable lambda function.
*/
const failable<lambda<value(const list<value>&)> > evalImplementation(const string& path, const value& impl, const list<value>& px) {
const string fpath(path + attributeValue("script", impl));
ifstream is(fpath);
if (fail(is))
return mkfailure<lambda<value(const list<value>&)> >(string("Could not read implementation: ") + fpath);
const value script = scheme::readScript(is);
if (isNil(script))
return mkfailure<lambda<value(const list<value>&)> >(string("Could not read implementation: ") + fpath);
return lambda<value(const list<value>&)>(applyImplementation(script, px));
}
}
}
}
#endif /* tuscany_modscheme_hpp */
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