review: feat(sniper): detailed tree of source fragments of compilation unit

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

@@ -17,10 +17,10 @@
 package spoon.reflect.cu;
 
 import spoon.processing.FactoryAccessor;
+import spoon.reflect.declaration.CtImport;
 import spoon.reflect.declaration.CtModule;
 import spoon.reflect.declaration.CtPackage;
 import spoon.reflect.declaration.CtType;
-import spoon.reflect.declaration.CtImport;
 import spoon.support.Experimental;
 
 import java.io.File;

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

@@ -16,9 +16,25 @@
  */
 package spoon.reflect.cu;
 
+import spoon.reflect.visitor.printer.internal.ElementSourceFragment;
+import spoon.support.Experimental;
+
 /**
- * This interface represents an element which knows it's position in a source file.
+ * This interface represents an element which knows its position in a source file.
  */
 public interface SourcePositionHolder {
+	/** If the element comes from a Java source file (hence has not created during transformation), returns the position in the original source file */
 	SourcePosition getPosition();
+
+	/**
+	 * Returns the original source code (maybe different from toString() if a transformation has been applied.
+	 * Or {@link ElementSourceFragment#NO_SOURCE_FRAGMENT} if this element has no original source fragment.
+	 *
+	 * Warning: this is a advanced method which cannot be considered as part of the stable API
+	 *
+	 */
+	@Experimental
+	default ElementSourceFragment getOriginalSourceFragment() {
+		return ElementSourceFragment.NO_SOURCE_FRAGMENT;
+	}
 }

src/main/java/spoon/reflect/visitor/printer/internal/CollectionSourceFragment.java

@@ -0,0 +1,88 @@
+/**
+ * Copyright (C) 2006-2018 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor.printer.internal;
+
+import java.util.List;
+
+import spoon.reflect.meta.ContainerKind;
+import spoon.reflect.path.CtRole;
+import spoon.support.Experimental;
+
+/**
+ * {@link SourceFragment} of List or Set of {@link ElementSourceFragment}s which belong to collection role.
+ * For example list of Type members or list of parameters, etc.
+ * Or set of modifiers and annotations
+ */
+@Experimental
+public class CollectionSourceFragment implements SourceFragment {
+
+	private final List<SourceFragment> items;
+
+	public CollectionSourceFragment(List<SourceFragment> items) {
+		super();
+		this.items = items;
+	}
+
+	@Override
+	public String getSourceCode() {
+		StringBuilder sb = new StringBuilder();
+		for (SourceFragment childSourceFragment : items) {
+			sb.append(childSourceFragment.getSourceCode());
+		}
+		return sb.toString();
+	}
+
+	/**
+	 * @return child source fragments of this collection
+	 */
+	public List<SourceFragment> getItems() {
+		return items;
+	}
+
+	@Override
+	public String toString() {
+		return items.toString();
+	}
+
+	/**
+	 * @return true if collection contains only children of one role handler with container kind LIST
+	 */
+	public boolean isOrdered() {
+		CtRole role = null;
+		ContainerKind kind = null;
+		for (SourceFragment childSourceFragment : items) {
+			if (childSourceFragment instanceof ElementSourceFragment) {
+				ElementSourceFragment esf = (ElementSourceFragment) childSourceFragment;
+				if (role == null) {
+					role = esf.getRoleInParent();
+					kind = esf.getContainerKindInParent();
+					if (kind != ContainerKind.LIST) {
+						return false;
+					}
+				} else {
+					if (role != esf.getRoleInParent()) {
+						//the collection contains elements of different roles. It cannot be ordered
+						return false;
+					}
+					//else there is another element of the same role - ok
+				}
+			}
+		}
+		//there are only elements of one role of container kind LIST
+		return true;
+	}
+}