From 907d20432605385cecc1a391da79f5081fcbdbc3 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Mon, 4 Nov 2024 17:33:11 +0000 Subject: [PATCH] Replace repeated sorts with one std::ranges::sort using a projection Instead of sorting several times in a row using different orderings, we can define a single projection that defines the desired final order. --- src/report_generator.cpp | 48 ++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 17 deletions(-) diff --git a/src/report_generator.cpp b/src/report_generator.cpp index 3cf74160f1..346f522bbc 100644 --- a/src/report_generator.cpp +++ b/src/report_generator.cpp @@ -63,6 +63,23 @@ struct order_by_major_section { lwg::section_map& section_db; }; +// Create a LessThanComparable object that defines an ordering based on date, +// with newer dates first. +auto ordered_date(lwg::issue const & issue) { + std::chrono::sys_days date(issue.mod_date); + return -date.time_since_epoch().count(); +} + +// Create a LessThanComparable object that defines an ordering that depends on +// the section number (e.g. 23.5.1) first and then on the section stable tag. +// Using both is not redundant, because we use section 99 for all sections of some TS's. +// Including the tag in the order gives a total order for sections in those TS's, +// e.g., {99,[arrays.ts::dynarray]} < {99,[arrays.ts::dynarraconstructible_from.cons]}. +auto ordered_section(lwg::section_map & section_db, lwg::issue const & issue) { + assert(!issue.tags.empty()); + return std::tie(section_db[issue.tags.front()], issue.tags.front()); +} + struct order_by_section { explicit order_by_section(lwg::section_map §ions) : section_db(sections) @@ -70,12 +87,7 @@ struct order_by_section { } auto operator()(lwg::issue const & x, lwg::issue const & y) const -> bool { - assert(!x.tags.empty()); - assert(!y.tags.empty()); - // This sorts by the section number (e.g. 23.5.1) then by the section stable tag. - // This is not redundant, because for e.g. Arrays TS the entire paper has section num 99, - // so including the tag orders [arrays.ts::dynarray] before [arrays.ts::dynarray.cons]. - return std::tie(section_db[x.tags.front()], x.tags.front()) < std::tie(section_db[y.tags.front()], y.tags.front()); + return ordered_section(section_db, x) < ordered_section(section_db, y); } private: @@ -696,10 +708,10 @@ sorted by priority.

void report_generator::make_sort_by_status(std::vector& issues, fs::path const & filename) { - sort(issues.begin(), issues.end(), order_by_issue_number{}); - stable_sort(issues.begin(), issues.end(), [](issue const & x, issue const & y) { return x.mod_date > y.mod_date; } ); - stable_sort(issues.begin(), issues.end(), order_by_section{section_db}); - stable_sort(issues.begin(), issues.end(), order_by_status{}); + auto proj = [this](const auto& i) { + return std::make_tuple(lwg::get_status_priority(i.stat), ordered_section(section_db, i), ordered_date(i), i.num); + }; + std::ranges::sort(issues.begin(), issues.end(), {}, proj); std::ofstream out{filename}; if (!out) @@ -733,10 +745,10 @@ This document is the Index by Status and Section for the void report_generator::make_sort_by_section(std::vector& issues, fs::path const & filename, bool active_only) { - sort(issues.begin(), issues.end(), order_by_issue_number{}); - stable_sort(issues.begin(), issues.end(), [](issue const & x, issue const & y) { return x.mod_date > y.mod_date; } ); - stable_sort(issues.begin(), issues.end(), order_by_status{}); + auto proj = [this](const auto& i) { + return std::make_tuple(lwg::get_status_priority(i.stat), ordered_date(i), i.num); + }; + std::ranges::sort(issues.begin(), issues.end(), {}, proj); + auto b = issues.begin(); auto e = issues.end(); if(active_only) {