decrease API breakage by using Set over Collection

Author: ix0rai

enigma/src/main/java/org/quiltmc/enigma/api/class_provider/ProjectClassProvider.java

@@ -7,6 +7,8 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
 
 public class ProjectClassProvider implements ClassProvider {
 	@Nullable
@@ -78,11 +80,11 @@ public Collection<String> getClassNames() {
 		return this.classNames;
 	}
 
-	public Collection<String> getMainClassNames() {
-		return this.main != null ? this.main.getClassNames() : Collections.emptySet();
+	public Set<String> getMainClassNames() {
+		return this.main != null ? new HashSet<>(this.main.getClassNames()) : Collections.emptySet();
 	}
 
-	public Collection<String> getLibraryClassNames() {
-		return this.libraries != null ? this.libraries.getClassNames() : Collections.emptySet();
+	public Set<String> getLibraryClassNames() {
+		return this.libraries != null ? new HashSet<>(this.libraries.getClassNames()) : Collections.emptySet();
 	}
 }

enigma/src/main/java/org/quiltmc/enigma/api/service/JarIndexerService.java

@@ -6,7 +6,7 @@
 import org.quiltmc.enigma.api.class_provider.ProjectClassProvider;
 
 import javax.annotation.Nullable;
-import java.util.Collection;
+import java.util.Set;
 
 /**
  * Jar indexer services analyse jar files as they're opened to collect information about their contents.
@@ -35,7 +35,7 @@ static boolean shouldIndexLibraries(@Nullable EnigmaServiceContext<JarIndexerSer
 	 * @param classProvider a provider to translate class names into {@link ClassNode class nodes}. Contains both library and main jar classes
 	 * @param jarIndex the current jar index
 	 */
-	void acceptJar(Collection<String> scope, ProjectClassProvider classProvider, JarIndex jarIndex);
+	void acceptJar(Set<String> scope, ProjectClassProvider classProvider, JarIndex jarIndex);
 
 	/**
 	 * Whether this indexer should be run on libraries in addition to the main project being indexed.
@@ -69,7 +69,7 @@ static JarIndexerService fromVisitor(@Nullable EnigmaServiceContext<JarIndexerSe
 
 		return new JarIndexerService() {
 			@Override
-			public void acceptJar(Collection<String> scope, ProjectClassProvider classProvider, JarIndex jarIndex) {
+			public void acceptJar(Set<String> scope, ProjectClassProvider classProvider, JarIndex jarIndex) {
 				for (String className : scope) {
 					ClassNode node = classProvider.get(className);
 					if (node != null) {

enigma/src/main/java/org/quiltmc/enigma/impl/analysis/index/AbstractJarIndex.java

@@ -25,7 +25,6 @@
 import org.quiltmc.enigma.api.translation.representation.entry.ParentedEntry;
 import org.quiltmc.enigma.util.I18n;
 
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -76,7 +75,7 @@ public <T extends JarIndexer> T getIndex(Class<T> clazz) {
 	 * @param classProvider a class provider containing all classes in the jar
 	 * @param progress a progress listener to track index completion
 	 */
-	public void indexJar(Collection<String> classNames, ClassProvider classProvider, ProgressListener progress) {
+	public void indexJar(Set<String> classNames, ClassProvider classProvider, ProgressListener progress) {
 		// for use in processIndex
 		this.progress = progress;