61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
#ifndef MUSIQUE_ALGO_HH
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#define MUSIQUE_ALGO_HH
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#include <musique/result.hh>
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#include <musique/try.hh>
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#include <musique/value/value.hh>
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#include <ranges>
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#include <compare>
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/// Generic algorithms support
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namespace algo
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{
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/// Check if predicate is true for all successive pairs of elements
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constexpr bool pairwise_all(
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auto &&range,
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auto &&binary_predicate)
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{
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auto it = std::begin(range);
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auto const end_it = std::end(range);
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for (auto next_it = std::next(it); it != end_it && next_it != end_it; ++it, ++next_it) {
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if (not binary_predicate(*it, *next_it)) {
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return false;
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}
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}
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return true;
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}
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/// Fold that stops iteration on error value via Result type
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template<typename T>
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constexpr Result<T> fold(auto&& range, T init, auto &&reducer)
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requires (is_template_v<Result, decltype(reducer(std::move(init), *range.begin()))>)
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{
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for (auto &&value : range) {
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init = Try(reducer(std::move(init), value));
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}
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return init;
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}
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/// Equavilent of std::lexicographical_compare_three_way
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///
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/// It's missing from MacOS C++ standard library
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constexpr auto lexicographical_compare(auto&& lhs_range, auto&& rhs_range)
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{
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auto lhs = lhs_range.begin();
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auto rhs = rhs_range.begin();
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decltype(*lhs <=> *rhs) result = std::partial_ordering::equivalent;
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for (; lhs != lhs_range.end() && rhs != rhs_range.end(); ++lhs, ++rhs) {
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if ((result = *lhs <=> *rhs) != 0) {
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return result;
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}
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}
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return result;
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}
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}
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/// Flattens one layer: `[[[1], 2], 3]` becomes `[[1], 2, 3]`
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Result<std::vector<Value>> flatten(Interpreter &i, std::span<Value>);
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Result<std::vector<Value>> flatten(Interpreter &i, std::vector<Value>);
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#endif
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