src/main/java/dev/frogmc/frogloader/impl/FrogLoaderImpl.java

@@ -115,7 +115,7 @@ public class FrogLoaderImpl implements FrogLoader {
 		gamePlugin = plugin;
 	}
 
-	private void loadModProviders() {
+	private void loadModProviders() throws Exception {
 		PluginLoader.discoverModProviders(gameDir, mods, modIds, modProviders);
 	}
 

src/main/java/dev/frogmc/frogloader/impl/PluginLoader.java

@@ -5,13 +5,17 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.ServiceLoader;
+import java.util.stream.Collectors;
 
 import dev.frogmc.frogloader.api.FrogLoader;
 import dev.frogmc.frogloader.api.mod.ModProperties;
 import dev.frogmc.frogloader.api.plugin.FrogGamePlugin;
 import dev.frogmc.frogloader.api.plugin.FrogModProvider;
+import dev.frogmc.frogloader.impl.gui.LoaderGui;
 import dev.frogmc.frogloader.impl.mixin.AWProcessor;
 import dev.frogmc.frogloader.impl.mod.BuiltinExtensions;
+import dev.frogmc.frogloader.impl.mod.ModDependencyResolver;
+import dev.frogmc.frogloader.impl.util.CrashReportGenerator;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.spongepowered.asm.mixin.Mixins;
@@ -19,7 +23,7 @@ import org.spongepowered.asm.mixin.Mixins;
 public class PluginLoader {
 	private static final Logger LOGGER = LoggerFactory.getLogger("FrogLoader/Plugins");
 
-	public static void discoverModProviders(Path gameDir, Map<String, Map<String, ModProperties>> mods, Collection<String> modIds, Collection<FrogModProvider> modProviders) {
+	public static void discoverModProviders(Path gameDir, Map<String, Map<String, ModProperties>> mods, Collection<String> modIds, Collection<FrogModProvider> modProviders) throws ModDependencyResolver.ResolverException {
 		LOGGER.info("Discovering mod providers...");
 
 		for (FrogModProvider plugin : ServiceLoader.load(FrogModProvider.class)) {
@@ -44,6 +48,16 @@ public class PluginLoader {
 				LOGGER.error("Error during plugin initialisation: ", e);
 			}
 		}
+
+		Collection<ModProperties> properties = mods.values().stream().map(Map::values).flatMap(Collection::stream).collect(Collectors.toUnmodifiableSet());
+		try {
+			Collection<ModProperties> solved = new  ModDependencyResolver(properties).solve();
+			mods.forEach((s, map) -> map.values().retainAll(solved));
+		} catch (ModDependencyResolver.UnfulfilledDependencyException e) {
+			LoaderGui.execUnfulfilledDep(CrashReportGenerator.writeReport(e, properties), e, false);
+		} catch (ModDependencyResolver.BreakingModException e) {
+			LoaderGui.execBreakingDep(CrashReportGenerator.writeReport(e, properties), e, false);
+		}
 	}
 
 	@SuppressWarnings({"rawtypes", "unchecked"})

src/main/java/dev/frogmc/frogloader/impl/mod/ModDependencyResolver.java

@@ -230,18 +230,10 @@ public class ModDependencyResolver {
 				throw new IllegalArgumentException(comparator);
 			}
 			var type = DependencyType.of(matcher.group(1));
-			StringBuilder version = new StringBuilder(matcher.group(2));
+			var version = matcher.group(2);
-
-			while (version.length() < 5) {
-				if (version.charAt(version.length() - 1) == '.') {
-					version.append('0');
-				} else {
-					version.append('.');
-				}
-			}
 
 			try {
-				return new Comparator(type, SemVerImpl.parse(version.toString()));
+				return new Comparator(type, SemVerImpl.parse(version));
 			} catch (SemVerParseException e) {
 				throw new UncheckedIOException(e);
 			}
@@ -325,6 +317,7 @@ public class ModDependencyResolver {
 	public record VersionRange(Collection<ComparatorSet> sets) {
 
 		private static final Pattern NUMBER_EXTRACTOR = Pattern.compile("[^~]?(\\d+)(?:\\.(?:([\\dxX*]+)(?:\\.([\\dxX*]+)?)?)?)?(.*)");
+		private static final Pattern FILL_PATTERN = Pattern.compile("[><=]+(\\d+)\\.?(\\d+)?\\.?(\\d+)?");
 
 		public static VersionRange parse(String range) throws ResolverException {
 
@@ -365,13 +358,7 @@ public class ModDependencyResolver {
 		private static void handleTilde(String s, List<String> ranges) throws ResolverException {
 			{
 				StringBuilder builder = new StringBuilder(">=" + s.substring(1));
-				while (builder.length() < 7) {
+				fillVersion(builder);
-					if (builder.charAt(builder.length() - 1) == '.') {
-						builder.append('0');
-					} else {
-						builder.append('.');
-					}
-				}
 				ranges.add(builder.toString());
 			}
 			ranges.add(" ");
@@ -393,13 +380,7 @@ public class ModDependencyResolver {
 		private static void handleXRanges(String s, List<String> ranges) throws ResolverException {
 			{
 				StringBuilder builder = new StringBuilder(">=" + s.replaceAll("[xX*]", "0"));
-				while (builder.length() < 7) {
+				fillVersion(builder);
-					if (builder.charAt(builder.length() - 1) == '.') {
-						builder.append('0');
-					} else {
-						builder.append('.');
-					}
-				}
 				ranges.add(builder.toString());
 			}
 
@@ -424,13 +405,7 @@ public class ModDependencyResolver {
 						break;
 					}
 				}
-				while (builder.length() < 6) {
+				fillVersion(builder);
-					if (builder.charAt(builder.length() - 1) == '.') {
-						builder.append('0');
-					} else {
-						builder.append('.');
-					}
-				}
 				ranges.add(builder.toString());
 			}
 		}
@@ -456,26 +431,21 @@ public class ModDependencyResolver {
 					break;
 				}
 			}
-			while (builder.length() < 6) {
+			fillVersion(builder);
+			/*while (builder.length() < 6) {
 				if (builder.charAt(builder.length() - 1) == '.') {
 					builder.append('0');
 				} else {
 					builder.append('.');
 				}
-			}
+			}*/
 			ranges.add(builder.toString());
 		}
 
 		private static void handleHyphenRange(String s, List<String> ranges, String end) throws ResolverException {
 			{
 				StringBuilder builder = new StringBuilder(">=" + s);
-				while (builder.length() < 7) {
+				fillVersion(builder);
-					if (builder.charAt(builder.length() - 1) == '.') {
-						builder.append('0');
-					} else {
-						builder.append('.');
-					}
-				}
 				ranges.add(builder.toString());
 				ranges.add(" ");
 			}
@@ -499,19 +469,35 @@ public class ModDependencyResolver {
 						break;
 					}
 				}
-				while (builder.length() < 6) {
+				fillVersion(builder);
-					if (builder.charAt(builder.length() - 1) == '.') {
-						builder.append('0');
-					} else {
-						builder.append('.');
-					}
-				}
 				ranges.add(builder.toString());
 			} else {
 				ranges.add("<=" + end);
 			}
 		}
 
+		private static void fillVersion(StringBuilder builder) {
+			Matcher matcher = FILL_PATTERN.matcher(builder);
+			if (!matcher.find()) {
+				return;
+			}
+
+			if (matcher.group(3) != null) {
+				return;
+			}
+
+			if (builder.charAt(builder.length() - 1) != '.') {
+				builder.append(".");
+			}
+
+			if (matcher.group(2) == null) {
+				builder.append("0.0");
+				return;
+			}
+
+			builder.append("0");
+		}
+
 		private static @NotNull List<String> extractRanges(String range) {
 			if (!range.contains(" ") && !range.contains(" - ") && !range.contains("||")) {
 				return List.of(range);

src/main/java/dev/frogmc/frogloader/impl/plugin/game/minecraft/MinecraftSemVerImpl.java

@@ -1,5 +1,8 @@
 package dev.frogmc.frogloader.impl.plugin.game.minecraft;
 
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 import dev.frogmc.frogloader.api.mod.SemVer;
 import dev.frogmc.frogloader.impl.SemVerParseException;
 import dev.frogmc.frogloader.impl.mod.SemVerImpl;
@@ -7,6 +10,7 @@ import org.jetbrains.annotations.NotNull;
 
 public class MinecraftSemVerImpl implements SemVer {
 
+	private static final Pattern FILL_PATTERN = Pattern.compile("(\\d+)\\.?(\\d+)?\\.?(\\d+)?");
 	private final String version;
 
 	private MinecraftSemVerImpl(String version) {
@@ -15,12 +19,36 @@ public class MinecraftSemVerImpl implements SemVer {
 
 	static SemVer get(String version) {
 		try {
-			return SemVerImpl.parse(version);
+			StringBuilder builder = new StringBuilder(version);
+			fillVersion(builder);
+			return SemVerImpl.parse(builder.toString());
 		} catch (SemVerParseException e) {
 			return new MinecraftSemVerImpl(version);
 		}
 	}
 
+	private static void fillVersion(StringBuilder builder) {
+		Matcher matcher = FILL_PATTERN.matcher(builder);
+		if (!matcher.find()) {
+			return;
+		}
+
+		if (matcher.group(3) != null) {
+			return;
+		}
+
+		if (builder.charAt(builder.length() - 1) != '.') {
+			builder.append(".");
+		}
+
+		if (matcher.group(2) == null) {
+			builder.append("0.0");
+			return;
+		}
+
+		builder.append("0");
+	}
+
 	@Override
 	public int major() {
 		throw new UnsupportedOperationException("Minecraft version " + version + " does not represent a semver-compatible version");