72 lines
1.6 KiB
C++
72 lines
1.6 KiB
C++
//
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// functools.hpp
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// libcommon
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//
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// Created by Bob Polis at 2019-10-19
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// Copyright (c) 2019 SwiftCoder. All rights reserved.
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//
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#ifndef _functools_H_
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#define _functools_H_
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#include <vector>
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#include <functional>
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#include <algorithm>
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#include <iterator>
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namespace sc {
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// std::vector versions
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template<class T, class M>
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std::vector<M> map(const std::vector<T>& seq, std::function<M(T)> fun) {
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std::vector<M> result;
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std::transform(seq.begin(), seq.end(), back_inserter(result), fun);
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return result;
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}
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template<class T>
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std::vector<T> filter(const std::vector<T>& seq, std::function<bool(T)> fun) {
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std::vector<T> result;
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std::copy_if(seq.begin(), seq.end(), back_inserter(result), fun);
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return result;
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}
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template<class T, class R>
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R reduce(const std::vector<T>& seq, R seed, std::function<R(T, R)> fun) {
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R result {seed};
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for (const auto& elem : seq) {
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result = fun(elem, result);
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}
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return result;
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}
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// iterator versions
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template<class T, class M, class FwdIter>
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std::vector<M> map(FwdIter& begin, FwdIter& end, std::function<M(T)> fun) {
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std::vector<M> result;
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std::transform(begin, end, std::back_inserter(result), fun);
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return result;
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}
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template<class T, class FwdIter>
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std::vector<T> filter(FwdIter& begin, FwdIter& end, std::function<bool(T)> fun) {
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std::vector<T> result;
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std::copy_if(begin, end, std::back_inserter(result), fun);
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return result;
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}
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template<class T, class R, class FwdIter>
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R reduce(FwdIter& begin, FwdIter& end, R seed, std::function<R(T, R)> fun) {
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R result {seed};
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for (FwdIter it = begin; it != end; ++it) {
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result = fun(*it, result);
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}
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return result;
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}
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}
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#endif // _functools_H_
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