Use string similarity as a program differentiator.

Analyser/Static/Acorn/Disk.cpp

@@ -201,5 +201,14 @@ std::unique_ptr<Catalogue> Analyser::Static::Acorn::GetADFSCatalogue(const std::
 		catalogue->files.push_back(std::move(new_file));
 	}
 
+	// Include the directory title.
+	const uint8_t *title;
+	if(catalogue->has_large_sectors) {
+		title = &root_directory[0x7dd];
+	} else {
+		title = &root_directory[0x4d9];
+	}
+	catalogue->name = std::string(reinterpret_cast<const char *>(title), 19);
+
 	return catalogue;
 }

Analyser/Static/Acorn/StaticAnalyser.cpp

@@ -12,7 +12,10 @@
 #include "Tape.hpp"
 #include "Target.hpp"
 
+#include "../../../Numeric/StringSimilarity.hpp"
+
 #include <algorithm>
+#include <map>
 
 using namespace Analyser::Static::Acorn;
 
@@ -148,10 +151,8 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 			targetArchimedes->media.disks = media.disks;
 
 			// Also look for the best possible startup program name, if it can be discerned.
+			std::map<double, std::string, std::greater<double>> options;
 			for(const auto &file: adfs_catalogue->files) {
-				// Skip files that would have been caught by shift-restart if suitable.
-				if(file.name == "!System" || file.name == "!Boot") continue;
-
 				// Skip non-Pling files.
 				if(file.name[0] != '!') continue;
 
@@ -167,9 +168,12 @@ Analyser::Static::TargetList Analyser::Static::Acorn::GetTargets(const Media &me
 						}
 					) != file.name.end();
 
-				if(targetArchimedes->main_program.empty() || !has_read) {
-					targetArchimedes->main_program = file.name;
-				}
+				const auto probability = Numeric::similarity(file.name, adfs_catalogue->name) * (has_read ? 0.5 : 1.0);
+				options.emplace(probability, file.name);
+			}
+
+			if(!options.empty()) {
+				targetArchimedes->main_program = options.begin()->second;
 			}
 		}
 	}

Numeric/StringSimilarity.hpp

@@ -0,0 +1,65 @@
+//
+//  StringSimilarity.hpp
+//  Clock Signal
+//
+//  Created by Thomas Harte on 21/05/2024.
+//  Copyright © 2024 Thomas Harte. All rights reserved.
+//
+
+#ifndef StringSimilarity_hpp
+#define StringSimilarity_hpp
+
+#include <cstdint>
+#include <set>
+#include <string>
+
+namespace Numeric {
+
+/// Seeks to implement algorithm as per http://www.catalysoft.com/articles/StrikeAMatch.html
+///
+/// @returns A number in the range 0.0 to 1.0 indicating the similarity between two strings;
+/// 1.0 is most similar, 0.0 is least.
+double similarity(std::string_view first, std::string_view second) {
+	if(first.size() < 2 || second.size() < 2) {
+		return 0.0;
+	}
+
+	const auto pairs = [](std::string_view source) -> std::set<uint16_t> {
+		std::set<uint16_t> result;
+		for(std::size_t c = 0; c < source.size() - 1; c++) {
+			if(isalpha(source[c]) && isalpha(source[c+1])) {
+				result.insert(static_cast<uint16_t>(
+					(toupper(source[c]) << 8) |
+					toupper(source[c+1])
+				));
+			}
+		}
+		return result;
+	};
+
+	const auto first_pairs = pairs(first);
+	const auto second_pairs = pairs(second);
+
+	const auto denominator = static_cast<double>(first_pairs.size() + second_pairs.size());
+
+	std::size_t numerator = 0;
+	auto first_it = first_pairs.begin();
+	auto second_it = second_pairs.begin();
+	while(first_it != first_pairs.end() && second_it != second_pairs.end()) {
+		if(*first_it == *second_it) {
+			++numerator;
+			++first_it;
+			++second_it;
+		} else if(*first_it < *second_it) {
+			++first_it;
+		} else {
+			++second_it;
+		}
+	}
+
+	return static_cast<double>(numerator * 2) / denominator;
+}
+
+}
+
+#endif /* StringSimilarity_h */

OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj

@@ -2268,6 +2268,7 @@
 		4BD9137D1F311BC5009BCF85 /* i8255.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = i8255.hpp; sourceTree = "<group>"; };
 		4BD91D762401C2B8007BDC91 /* PatrikRakTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PatrikRakTests.swift; sourceTree = "<group>"; };
 		4BD971382BFC3D9C00C907AA /* ArchimedesStaticAnalyserTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = ArchimedesStaticAnalyserTests.mm; sourceTree = "<group>"; };
+		4BD9713A2BFD7E7100C907AA /* StringSimilarity.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = StringSimilarity.hpp; sourceTree = "<group>"; };
 		4BDA00D922E60EE300AC3CD0 /* ROMRequester.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = ROMRequester.xib; sourceTree = "<group>"; };
 		4BDA00DE22E644AF00AC3CD0 /* CSROMReceiverView.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CSROMReceiverView.h; sourceTree = "<group>"; };
 		4BDA00DF22E644AF00AC3CD0 /* CSROMReceiverView.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CSROMReceiverView.m; sourceTree = "<group>"; };
@@ -3528,6 +3529,7 @@
 				4BB5B995281B1D3E00522DA9 /* RegisterSizes.hpp */,
 				4BFEA2F12682A90200EBF94C /* Sizes.hpp */,
 				4281572E2AA0334300E16AA1 /* Carry.hpp */,
+				4BD9713A2BFD7E7100C907AA /* StringSimilarity.hpp */,
 			);
 			name = Numeric;
 			path = ../../Numeric;