From 54e3332673808502575e996b7c70b7dcad606036 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 6 Jun 2021 22:36:26 -0400
Subject: [PATCH] Ensure optionals appear at the end of any ROM request list.

---
 Machines/Utility/ROMCatalogue.cpp |  3 +++
 Machines/Utility/ROMCatalogue.hpp | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/Machines/Utility/ROMCatalogue.cpp b/Machines/Utility/ROMCatalogue.cpp
index 5b2d1a24a..7a12069ff 100644
--- a/Machines/Utility/ROMCatalogue.cpp
+++ b/Machines/Utility/ROMCatalogue.cpp
@@ -32,6 +32,7 @@ Request Request::append(Node::Type type, const Request &rhs) {
 	if(node.type == type && rhs.node.type == type) {
 		Request new_request = *this;
 		new_request.node.children.insert(new_request.node.children.end(), rhs.node.children.begin(), rhs.node.children.end());
+		new_request.node.sort();
 		return new_request;
 	}
 
@@ -39,6 +40,7 @@ Request Request::append(Node::Type type, const Request &rhs) {
 	if(node.type == type && rhs.node.type == Node::Type::One) {
 		Request new_request = *this;
 		new_request.node.children.push_back(rhs.node);
+		new_request.node.sort();
 		return new_request;
 	}
 
@@ -46,6 +48,7 @@ Request Request::append(Node::Type type, const Request &rhs) {
 	if(rhs.node.type == type && node.type == Node::Type::One) {
 		Request new_request = rhs;
 		new_request.node.children.push_back(node);
+		new_request.node.sort();
 		return new_request;
 	}
 
diff --git a/Machines/Utility/ROMCatalogue.hpp b/Machines/Utility/ROMCatalogue.hpp
index c3d541915..88ec7ca5b 100644
--- a/Machines/Utility/ROMCatalogue.hpp
+++ b/Machines/Utility/ROMCatalogue.hpp
@@ -9,6 +9,7 @@
 #ifndef ROMCatalogue_hpp
 #define ROMCatalogue_hpp
 
+#include <algorithm>
 #include <functional>
 #include <map>
 #include <optional>
@@ -244,6 +245,19 @@ struct Request {
 				const std::function<void(ROM::Request::ListType type, const ROM::Description &, bool is_optional, size_t remaining)> &add_item
 			) const;
 			bool subtract(const ROM::Map &map);
+			void sort() {
+				// Don't do a full sort, but move anything optional to the back.
+				// This makes them print more nicely; it's a human-facing tweak only.
+				ssize_t index = ssize_t(children.size() - 1);
+				bool has_seen_non_optional = false;
+				while(index >= 0) {
+					has_seen_non_optional |= !children[size_t(index)].is_optional;
+					if(children[size_t(index)].is_optional && has_seen_non_optional) {
+						std::rotate(children.begin() + index, children.begin() + index + 1, children.end());
+					}
+					--index;
+				}
+			}
 		};
 		Node node;