review refactor: prepare import API for future development

src/main/java/spoon/reflect/cu/CompilationUnit.java

@@ -21,11 +21,12 @@
 import spoon.reflect.declaration.CtPackage;
 import spoon.reflect.declaration.CtType;
 import spoon.reflect.declaration.CtImport;
+import spoon.support.Experimental;
 
 import java.io.File;
 import java.io.Serializable;
-import java.util.Collection;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Defines a compilation unit. In Java, a compilation unit can contain only one
@@ -139,15 +140,19 @@ enum UNIT_TYPE {
 	int getTabCount(int index);
 
 	/**
-	 * Get the imports computed for this CU
+	 * Get the imports computed for this CU.
+	 * WARNING: This method is tagged as experimental, as its signature and/or usage might change in future release.
 	 * @return All the imports from the original source code
 	 */
-	Collection<CtImport> getImports();
+	@Experimental
+	Set<CtImport> getImports();
 
 	/**
 	 * Set the imports of this CU
+	 * WARNING: This method is tagged as experimental, as its signature and/or usage might change in future release.
 	 * @param imports All the imports of the original source code
 	 */
-	void setImports(Collection<CtImport> imports);
+	@Experimental
+	void setImports(Set<CtImport> imports);
 
 }

src/main/java/spoon/reflect/visitor/ImportScanner.java

@@ -19,12 +19,15 @@
 import spoon.reflect.declaration.CtElement;
 import spoon.reflect.declaration.CtImport;
 import spoon.reflect.reference.CtReference;
+import spoon.support.Experimental;
 
-import java.util.Collection;
+import java.util.Set;
 
 /**
  * Used to compute the imports required to write readable code with no fully qualified names.
+ * The import scanner API might still change in future release, that's why it is marked as experimental.
  */
+@Experimental
 public interface ImportScanner {
 
 	/**
@@ -37,7 +40,7 @@ public interface ImportScanner {
 	 *
 	 * @return the list of computed imports or an empty collection if not imports has been computed.
 	 */
-	Collection<CtImport> getAllImports();
+	Set<CtImport> getAllImports();
 
 	/**
 	 * Checks if the type is already imported.
@@ -47,5 +50,5 @@ public interface ImportScanner {
 	/**
 	 * Specify the original imports to use before computing new imports.
 	 */
-	void initWithImports(Collection<CtImport> importCollection);
+	void initWithImports(Set<CtImport> importCollection);
 }

src/main/java/spoon/reflect/visitor/ImportScannerImpl.java

@@ -47,7 +47,6 @@
 import spoon.support.SpoonClassNotFoundException;
 
 import java.lang.annotation.Annotation;
-import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
@@ -235,8 +234,8 @@ public void visitCtInvocation(CtInvocation invocation) {
 	}
 
 	@Override
-	public Collection<CtImport> getAllImports() {
-		Collection<CtImport> listallImports = new ArrayList<>();
+	public Set<CtImport> getAllImports() {
+		Set<CtImport> listallImports = new HashSet<>();
 
 		for (Map.Entry<CtImport, Boolean> entry : this.usedImport.entrySet()) {
 			if (entry.getValue()) {
@@ -287,7 +286,7 @@ public boolean isImported(CtReference ref) {
 	}
 
 	@Override
-	public void initWithImports(Collection<CtImport> importCollection) {
+	public void initWithImports(Set<CtImport> importCollection) {
 		for (CtImport ctImport : importCollection) {
 			this.usedImport.put(ctImport, Boolean.FALSE);
 		}

src/main/java/spoon/support/reflect/cu/CompilationUnitImpl.java

@@ -32,10 +32,10 @@
 import java.io.FileInputStream;
 import java.nio.file.Paths;
 import java.util.ArrayList;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import static spoon.reflect.ModelElementContainerDefaultCapacities.COMPILATION_UNIT_DECLARED_TYPES_CONTAINER_DEFAULT_CAPACITY;
 
@@ -48,7 +48,7 @@ public class CompilationUnitImpl implements CompilationUnit, FactoryAccessor {
 
 	CtPackage ctPackage;
 
-	Collection<CtImport> imports = new HashSet<>();
+	Set<CtImport> imports = new HashSet<>();
 
 	CtModule ctModule;
 
@@ -245,12 +245,12 @@ public int getTabCount(int index) {
 	}
 
 	@Override
-	public Collection<CtImport> getImports() {
+	public Set<CtImport> getImports() {
 		return this.imports;
 	}
 
 	@Override
-	public void setImports(Collection<CtImport> imports) {
+	public void setImports(Set<CtImport> imports) {
 		this.imports = imports;
 	}