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/*
* This source code is released into the public domain.
*/
#ifndef LIBLFJAIL_WORDS_HH
#define LIBLFJAIL_WORDS_HH
#include <algorithm>
#include <ranges>
#include "ctype.hh"
#include "generator.hh"
namespace lfjail {
/*
* words: take a string-like object and split it into words using the given
* predicate. Empty values are discarded (i.e., repeated separators are
* ignored).
*/
namespace detail {
template<std::ranges::range Range,
std::indirect_unary_predicate<std::ranges::iterator_t<Range>> Pred>
auto split(Range &&text, Pred pred) -> std::generator<std::string>
{
auto pos = std::ranges::begin(text);
auto end = std::ranges::end(text);
for (;;) {
// Skip leading whitespace.
pos = std::find_if_not(pos, end, pred);
// If there's no string left, we're done.
if (pos == end)
break;
// Find the end of the next word.
auto split_pos = std::find_if(pos, end, pred);
// Yield this word.
co_yield std::string(pos, split_pos);
pos = split_pos;
}
}
template<typename Pred>
struct words_fn : std::ranges::range_adaptor_closure<words_fn<Pred>> {
words_fn(Pred p) : _pred(std::move(p)) {}
template<std::ranges::range Range>
constexpr auto operator()(Range &&range) const {
return detail::split(std::forward<Range>(range),
std::move(_pred));
}
private:
Pred _pred;
};
} // namespace detail
template<std::ranges::range Range,
std::indirect_unary_predicate<std::ranges::iterator_t<Range>> Pred>
auto words(Range &&range, Pred pred)
{
return detail::split(std::forward<Range>(range), std::move(pred));
}
template<std::ranges::viewable_range Range, std::integral Char>
auto words(Range &&range, Char ch) {
return words(std::forward<Range>(range),
[ch](auto c) { return c == ch; });
}
template<std::ranges::viewable_range Range>
auto words(Range &&range) {
return words(std::forward<Range>(range), is_c_space);
}
template<typename Pred>
requires(!std::integral<Pred> && !std::ranges::range<Pred>)
auto words(Pred pred) {
return detail::words_fn(std::move(pred));
}
auto words() {
return words(is_c_space);
}
template<std::integral Char>
auto words(Char ch) {
return words([ch](auto c) { return c == ch; });
}
//constexpr words_impl words{};
} // namespace lfjail
#endif // LIBLFJAIL_WORDS_HH
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