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-rw-r--r-- | sca-cpp/branches/lightweight-sca/modules/server/mod-scheme.hpp | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/sca-cpp/branches/lightweight-sca/modules/server/mod-scheme.hpp b/sca-cpp/branches/lightweight-sca/modules/server/mod-scheme.hpp new file mode 100644 index 0000000000..43d7bf4041 --- /dev/null +++ b/sca-cpp/branches/lightweight-sca/modules/server/mod-scheme.hpp @@ -0,0 +1,91 @@ +/* + * 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 */ |