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// Copyright 2021 Benjamin Barenblat
//
// Licensed 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
//
// https://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.
#include "src/language.h"
#include <stdint.h>
#include <memory>
#include <sstream>
#include <string>
#include <vector>
#include "src/builtin.h"
#include "third_party/abseil/absl/strings/str_cat.h"
namespace ec {
State::State() noexcept : environment(BuiltinEnvironment()) {}
void GroundTerm::Evaluate(State& state) const noexcept {
state.stack.push_back(Clone());
}
std::string GroundTerm::Show() const noexcept {
// A double-precision value has 13 decimal digits of precision.
std::ostringstream s;
s.precision(13);
s << value_;
return s.str();
}
std::string GroundTerm::DebugString() const noexcept {
return absl::StrCat("GroundTerm(", value_, ")");
}
GroundTerm* GroundTerm::CloneImpl() const noexcept {
return new GroundTerm(*this);
}
void ForeignProgramTerm::Evaluate(State& state) const { impl_(state); }
std::string ForeignProgramTerm::Show() const noexcept { return "<program>"; }
std::string ForeignProgramTerm::DebugString() const noexcept {
return absl::StrCat("ForeignProgramTerm(", reinterpret_cast<uintptr_t>(impl_),
")");
}
ForeignProgramTerm* ForeignProgramTerm::CloneImpl() const noexcept {
return new ForeignProgramTerm(*this);
}
void SymbolTerm::Evaluate(State& state) const {
auto it = state.environment.find(name_);
if (it == state.environment.end()) {
throw UndefinedName(name_);
}
it->second->Evaluate(state);
}
std::string SymbolTerm::Show() const noexcept {
return absl::StrCat("'", name_);
}
std::string SymbolTerm::DebugString() const noexcept {
return absl::StrCat("SymbolTerm(", name_, ")");
}
SymbolTerm* SymbolTerm::CloneImpl() const noexcept {
return new SymbolTerm(*this);
}
void FormatStackElement(std::string* out,
std::shared_ptr<const Term> term) noexcept {
out->append(term->Show());
}
void EvaluateAll(const Program& program, State& state) {
for (auto term : program) {
term->Evaluate(state);
}
}
} // namespace ec
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