Difference.java
/*
* Copyright (C) 2007-2010 J��lio Vilmar Gesser.
* Copyright (C) 2011, 2013-2023 The JavaParser Team.
*
* This file is part of JavaParser.
*
* JavaParser can be used either under the terms of
* a) the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* b) the terms of the Apache License
*
* You should have received a copy of both licenses in LICENCE.LGPL and
* LICENCE.APACHE. Please refer to those files for details.
*
* JavaParser 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
* GNU Lesser General Public License for more details.
*/
package com.github.javaparser.printer.lexicalpreservation;
import static com.github.javaparser.GeneratedJavaParserConstants.*;
import java.util.*;
import java.util.function.Predicate;
import java.util.stream.IntStream;
import com.github.javaparser.GeneratedJavaParserConstants;
import com.github.javaparser.JavaToken;
import com.github.javaparser.JavaToken.Kind;
import com.github.javaparser.TokenTypes;
import com.github.javaparser.ast.Node;
import com.github.javaparser.ast.NodeList;
import com.github.javaparser.ast.comments.Comment;
import com.github.javaparser.ast.nodeTypes.NodeWithTypeArguments;
import com.github.javaparser.ast.type.ArrayType;
import com.github.javaparser.ast.type.ClassOrInterfaceType;
import com.github.javaparser.ast.type.Type;
import com.github.javaparser.printer.concretesyntaxmodel.CsmElement;
import com.github.javaparser.printer.concretesyntaxmodel.CsmIndent;
import com.github.javaparser.printer.concretesyntaxmodel.CsmUnindent;
import com.github.javaparser.printer.lexicalpreservation.LexicalDifferenceCalculator.CsmChild;
/**
* A Difference should give me a sequence of elements I should find (to indicate the context) followed by a list of elements
* to remove or to add and follow by another sequence of elements.
*
* I should later be able to apply such difference to a nodeText.
*/
public class Difference {
public static final int STANDARD_INDENTATION_SIZE = 4;
private final NodeText nodeText;
private final Node node;
private final List<DifferenceElement> diffElements;
private final List<TextElement> originalElements;
private int originalIndex = 0;
private int diffIndex = 0;
private final List<TextElement> indentation;
private boolean addedIndentation = false;
Difference(List<DifferenceElement> diffElements, NodeText nodeText, Node node) {
if (nodeText == null) {
throw new NullPointerException("nodeText can not be null");
}
this.nodeText = nodeText;
this.node = node;
this.diffElements = diffElements;
this.originalElements = nodeText.getElements();
this.indentation = LexicalPreservingPrinter.findIndentation(node);
}
/*
* Returns the indentation used after the last line break
*/
List<TextElement> processIndentation(List<TextElement> indentation, List<TextElement> prevElements) {
int eolIndex = lastIndexOfEol(prevElements);
// Return "indentation" as is if no EOL element was found
if (eolIndex < 0)
return indentation;
// Find consecutive space characters after the EOL element
indentation = takeWhile(prevElements.subList(eolIndex + 1, prevElements.size()), element -> element.isWhiteSpace());
return indentation;
}
/*
* returns only the elements that match the given predicate.
* takeWhile takes elements from the initial stream while the predicate holds true.
* Meaning that when an element is encountered that does not match the predicate, the rest of the list is discarded.
*/
List<TextElement> takeWhile(List<TextElement> prevElements, Predicate<TextElement> predicate) {
List<TextElement> spaces = new ArrayList<>();
for (TextElement element : prevElements) {
if (predicate.test(element)) {
spaces.add(element);
continue;
}
break;
}
return spaces;
}
int lastIndexOfEol(List<TextElement> source) {
return IntStream.range(0, source.size())
.map(i -> source.size() - i - 1)
.filter(i -> source.get(i).isNewline())
.findFirst()
.orElse(-1);
}
/*
* Returns the position of the next element in the list starting from @{code fromIndex} which is a comment (Ignoring spaces)
* or -1 if it's not a comment.
*/
private int posOfNextComment(int fromIndex, List<TextElement> elements) {
if (!isValidIndex(fromIndex, elements))
return -1;
ArrayIterator<TextElement> iterator = new ArrayIterator<>(elements, fromIndex);
// search for the next consecutive space characters
while (iterator.hasNext()) {
TextElement element = iterator.next();
if (element.isSpaceOrTab()) {
continue;
}
if (element.isComment()) {
return iterator.index();
}
break;
}
return -1;
}
/*
* Returns true if the next element in the list (starting from @{code fromIndex}) is a comment
*/
private boolean isFollowedByComment(int fromIndex, List<TextElement> elements) {
return posOfNextComment(fromIndex, elements) != -1;
}
/*
* Removes all elements in the list starting from @{code fromIndex}) ending to @{code toIndex})
*/
private void removeElements(int fromIndex, int toIndex, List<TextElement> elements) {
if (!(isValidIndex(fromIndex, elements) && isValidIndex(toIndex, elements) && fromIndex <= toIndex))
return;
ListIterator<TextElement> iterator = elements.listIterator(fromIndex);
// removing elements
int count = fromIndex;
while (iterator.hasNext() && count <= toIndex) {
iterator.next();
iterator.remove();
count++;
}
}
private boolean isValidIndex(int index, List<?> elements) {
return index >= 0 && index <= elements.size();
}
/*
* Returns the position of the last new line character or -1 if there is no eol in the specified list of TextElement
*/
int lastIndexOfEolWithoutGPT(List<TextElement> source) {
ListIterator<TextElement> listIterator = source.listIterator(source.size());
int lastIndex = source.size() - 1;
while (listIterator.hasPrevious()) {
TextElement elem = listIterator.previous();
if (elem.isNewline()) {
return lastIndex;
}
lastIndex--;
}
return -1;
}
private List<TextElement> indentationBlock() {
List<TextElement> res = new LinkedList<>();
res.add(new TokenTextElement(SPACE));
res.add(new TokenTextElement(SPACE));
res.add(new TokenTextElement(SPACE));
res.add(new TokenTextElement(SPACE));
return res;
}
private boolean isAfterLBrace(NodeText nodeText, int nodeTextIndex) {
if (nodeTextIndex > 0 && nodeText.getTextElement(nodeTextIndex - 1).isToken(LBRACE)) {
return true;
}
if (nodeTextIndex > 0 && nodeText.getTextElement(nodeTextIndex - 1).isSpaceOrTab()) {
return isAfterLBrace(nodeText, nodeTextIndex - 1);
}
return false;
}
/**
* If we are at the beginning of a line, with just spaces or tabs before/after the position of the deleted element
* we should force the space to be the same as the current indentation.
* This method handles the following case if we remove the modifier {@code public} ([ ] is an indent character)
* {@code
* [ ][ ]public[ ][ ][ ]void[ ]m{}
* <-1--> <---2--->
* 1/ current indentation
* 2/ these whitespaces must be removed
* }
* should produce
* {@code
* [ ][ ]void[ ]m{}
* }
*/
int considerEnforcingIndentation(NodeText nodeText, int nodeTextIndex) {
return considerIndentation(nodeText, nodeTextIndex, indentation.size());
}
private int considerRemovingIndentation(NodeText nodeText, int nodeTextIndex) {
return considerIndentation(nodeText, nodeTextIndex, 0);
}
private int considerIndentation(NodeText nodeText, int nodeTextIndex, int numberOfCharactersToPreserve) {
EnforcingIndentationContext enforcingIndentationContext = defineEnforcingIndentationContext(nodeText, nodeTextIndex);
// the next position in the list (by default the current position)
int res = nodeTextIndex;
if (enforcingIndentationContext.extraCharacters > 0) {
int extraCharacters = enforcingIndentationContext.extraCharacters > numberOfCharactersToPreserve ? enforcingIndentationContext.extraCharacters - numberOfCharactersToPreserve : 0;
res = removeExtraCharacters(nodeText, enforcingIndentationContext.start, extraCharacters);
// The next position must take into account the indentation
res = extraCharacters > 0 ? res + numberOfCharactersToPreserve : res;
}
if (res < 0) {
throw new IllegalStateException();
}
return res;
}
private boolean isEnforcingIndentationActivable(RemovedGroup removedGroup) {
return (isLastElement(diffElements, diffIndex) || !(nextDiffElement(diffElements,diffIndex).isAdded()))
&& originalIndex < originalElements.size()
&& !removedGroup.isACompleteLine();
}
private boolean isRemovingIndentationActivable(RemovedGroup removedGroup) {
return (isLastElement(diffElements, diffIndex) || !(nextDiffElement(diffElements,diffIndex).isAdded()))
&& originalIndex < originalElements.size()
&& removedGroup.isACompleteLine();
}
private boolean isLastElement(List<?> list, int index) {
return index + 1 >= list.size();
}
private DifferenceElement nextDiffElement(List<DifferenceElement> list, int index) {
return list.get(index + 1);
}
/*
* This data structure class hold the starting position of the first whitespace char
* and the number of consecutive whitespace (or tab) characters
*/
private class EnforcingIndentationContext {
int start;
int extraCharacters;
public EnforcingIndentationContext(int start) {
this(start,0);
}
public EnforcingIndentationContext(int start, int extraCharacters) {
this.start=start;
this.extraCharacters=extraCharacters;
}
}
/**
* Remove excess white space after deleting element.
* @param nodeText Contains a list of elements to analyze
* @param nodeTextIndex Starting position in the input list
* @return The current position in the list of the elements
*/
private int removeExtraCharacters(NodeText nodeText, int nodeTextIndex, int extraCharacters) {
int count = 0;
while (nodeTextIndex >= 0 && nodeTextIndex < nodeText.numberOfElements() && count < extraCharacters) {
nodeText.removeElement(nodeTextIndex);
count++;
}
return nodeTextIndex;
}
/**
* Starting at {@code nodeTextIndex} this method tries to determine how many contiguous spaces there are between
* the previous end of line and the next non whitespace (or tab) character
* @param nodeText List of elements to analyze
* @param nodeTextIndex Starting position in the input list
* @return EnforcingIndentationContext Data structure that hold the starting position of the first whitespace char and
* The number of consecutive whitespace (or tab) characters
*/
private EnforcingIndentationContext defineEnforcingIndentationContext(NodeText nodeText, int startIndex) {
EnforcingIndentationContext ctx = new EnforcingIndentationContext(startIndex);
// compute space before startIndex value
if (startIndex < nodeText.numberOfElements() && startIndex > 0) {
// at this stage startIndex points to the first element before the deleted one
for (int i = startIndex - 1; i >= 0 && i < nodeText.numberOfElements(); i--) {
if (nodeText.getTextElement(i).isNewline()) {
break;
}
if (!isSpaceOrTabElement(nodeText, i)) {
ctx = new EnforcingIndentationContext(startIndex);
break;
}
ctx.start = i;
ctx.extraCharacters++;
}
}
// compute space after the deleted element
if (startIndex < nodeText.numberOfElements() && isSpaceOrTabElement(nodeText, startIndex)) {
// int startingFromIndex = startIndex == 0 ? startIndex : startIndex + 1;
for (int i = startIndex; i >= 0 && i < nodeText.numberOfElements(); i++) {
if (nodeText.getTextElement(i).isNewline()) {
break;
}
if (!isSpaceOrTabElement(nodeText, i)) {
break;
}
ctx.extraCharacters++;
}
}
return ctx;
}
/*
* Returns true if the indexed element is a space or a tab
*/
private boolean isSpaceOrTabElement(NodeText nodeText, int i) {
return nodeText.getTextElement(i).isSpaceOrTab();
}
/**
* Node that we have calculate the Difference we can apply to a concrete NodeText, modifying it according
* to the difference (adding and removing the elements provided).
*/
void apply() {
ReshuffledDiffElementExtractor.of(nodeText).extract(diffElements);
Map<Removed, RemovedGroup> removedGroups = combineRemovedElementsToRemovedGroups();
do {
boolean isLeftOverDiffElement = applyLeftOverDiffElements();
boolean isLeftOverOriginalElement = applyLeftOverOriginalElements();
if (!isLeftOverDiffElement && !isLeftOverOriginalElement) {
DifferenceElement diffElement = diffElements.get(diffIndex);
if (diffElement.isAdded()) {
applyAddedDiffElement((Added) diffElement);
} else {
TextElement originalElement = originalElements.get(originalIndex);
boolean originalElementIsChild = originalElement instanceof ChildTextElement;
boolean originalElementIsToken = originalElement instanceof TokenTextElement;
if (diffElement.isKept()) {
applyKeptDiffElement((Kept) diffElement, originalElement, originalElementIsChild, originalElementIsToken);
} else if (diffElement.isRemoved()) {
Removed removed = (Removed) diffElement;
applyRemovedDiffElement(removedGroups.get(removed), removed, originalElement, originalElementIsChild, originalElementIsToken);
} else {
throw new UnsupportedOperationException("" + diffElement + " vs " + originalElement);
}
}
}
} while (diffIndex < diffElements.size() || originalIndex < originalElements.size());
}
private boolean applyLeftOverOriginalElements() {
boolean isLeftOverElement = false;
if (diffIndex >= diffElements.size() && originalIndex < originalElements.size()) {
TextElement originalElement = originalElements.get(originalIndex);
if (originalElement.isWhiteSpaceOrComment()) {
originalIndex++;
} else {
throw new UnsupportedOperationException("NodeText: " + nodeText + ". Difference: " + this + " " + originalElement);
}
isLeftOverElement = true;
}
return isLeftOverElement;
}
private boolean applyLeftOverDiffElements() {
boolean isLeftOverElement = false;
if (diffIndex < diffElements.size() && originalIndex >= originalElements.size()) {
DifferenceElement diffElement = diffElements.get(diffIndex);
if (diffElement.isKept()) {
diffIndex++;
} else if (diffElement.isAdded()) {
Added addedElement = (Added) diffElement;
nodeText.addElement(originalIndex, addedElement.toTextElement());
originalIndex++;
diffIndex++;
} else {
// let's forget this element
diffIndex++;
}
isLeftOverElement = true;
}
return isLeftOverElement;
}
/**
* Maps all Removed elements as keys to their corresponding RemovedGroup.
* A RemovedGroup contains all consecutive Removed elements.
* <br>
* Example:
* <pre>
* Elements: Kept|Removed1|Removed2|Kept|Removed3|Added|Removed4
* Groups: <----Group1----> Group2 Group3
* Keys: Removed1+Removed2 Removed3 Removed4
* </pre>
*
* @return Map with all Removed elements as keys to their corresponding RemovedGroup
*/
private Map<Removed, RemovedGroup> combineRemovedElementsToRemovedGroups() {
Map<Integer, List<Removed>> removedElementsMap = groupConsecutiveRemovedElements();
List<RemovedGroup> removedGroups = new ArrayList<>();
for (Map.Entry<Integer, List<Removed>> entry : removedElementsMap.entrySet()) {
removedGroups.add(RemovedGroup.of(entry.getKey(), entry.getValue()));
}
Map<Removed, RemovedGroup> map = new HashMap<>();
for (RemovedGroup removedGroup : removedGroups) {
for (Removed index : removedGroup) {
map.put(index, removedGroup);
}
}
return map;
}
private Map<Integer, List<Removed>> groupConsecutiveRemovedElements() {
Map<Integer, List<Removed>> removedElementsMap = new HashMap<>();
Integer firstElement = null;
for (int i = 0; i < diffElements.size(); i++) {
DifferenceElement diffElement = diffElements.get(i);
if (diffElement.isRemoved()) {
if (firstElement == null) {
firstElement = i;
}
removedElementsMap.computeIfAbsent(firstElement, key -> new ArrayList<>()).add((Removed) diffElement);
} else {
firstElement = null;
}
}
return removedElementsMap;
}
private void applyRemovedDiffElement(RemovedGroup removedGroup, Removed removed, TextElement originalElement, boolean originalElementIsChild, boolean originalElementIsToken) {
if (removed.isChild() && originalElementIsChild) {
ChildTextElement originalElementChild = (ChildTextElement) originalElement;
if (originalElementChild.isComment()) {
// We expected to remove a proper node but we found a comment in between.
// If the comment is associated to the node we want to remove we remove it as well, otherwise we keep it
Comment comment = (Comment) originalElementChild.getChild();
if (!comment.isOrphan() && comment.getCommentedNode().isPresent() && comment.getCommentedNode().get().equals(removed.getChild())) {
nodeText.removeElement(originalIndex);
} else {
originalIndex++;
}
} else {
nodeText.removeElement(originalIndex);
// When we don't try to remove a complete line
// and removing the element is not the first action of a replacement (removal followed by addition)
// (in the latter case we keep the indentation)
// then we want to enforce the indentation.
if (isEnforcingIndentationActivable(removedGroup)) {
// Since the element has been deleted we try to start the analysis from the element following the one that was deleted
originalIndex = considerEnforcingIndentation(nodeText, originalIndex);
}
// If in front we have one space and before also we had space let's drop one space
if (originalElements.size() > originalIndex && originalIndex > 0) {
if (originalElements.get(originalIndex).isWhiteSpace() && originalElements.get(originalIndex - 1).isWhiteSpace()) {
// However we do not want to do that when we are about to adding or removing elements
// The intention is not very clear maybe it should clarify this with examples!
// Are we to understand that we can only do this if there is a single modification to process
// OR or if the next change is to keep the element
if ((diffIndex + 1) == diffElements.size() || (diffElements.get(diffIndex + 1).isKept())) {
originalElements.remove(originalIndex--);
}
}
}
// We need to know if, in the original list of elements, the deleted child node is immediately followed by the same comment.
// If so, it should also be deleted.
if (isFollowedByComment(originalIndex, originalElements) ) {
int indexOfNextComment = posOfNextComment(originalIndex, originalElements);
removeElements(originalIndex, indexOfNextComment, originalElements);
}
if (isRemovingIndentationActivable(removedGroup)) {
// Since the element has been deleted we try to start the analysis from the previous element
originalIndex = considerRemovingIndentation(nodeText, originalIndex);
}
diffIndex++;
}
} else if (removed.isChild() && originalElement.isComment()) {
// removing the comment first
nodeText.removeElement(originalIndex);
if (isRemovingIndentationActivable(removedGroup)) {
originalIndex = considerRemovingIndentation(nodeText, originalIndex);
}
} else if (removed.isToken() && originalElementIsToken && (removed.getTokenType() == ((TokenTextElement) originalElement).getTokenKind() || // handle EOLs separately as their token kind might not be equal. This is because the 'removed'
// element always has the current operating system's EOL as type
(((TokenTextElement) originalElement).getToken().getCategory().isEndOfLine() && removed.isNewLine()))) {
nodeText.removeElement(originalIndex);
diffIndex++;
} else if ((removed.isWhiteSpaceNotEol() || removed.getElement() instanceof CsmIndent || removed.getElement() instanceof CsmUnindent)
&& originalElement.isSpaceOrTab()){
// remove the current space
nodeText.removeElement(originalIndex);
}else if (originalElementIsToken && originalElement.isWhiteSpaceOrComment()) {
originalIndex++;
// skip the newline token which may be generated unnecessarily by the concrete syntax pattern
if (removed.isNewLine()) {
diffIndex++;
}
} else if (originalElement.isLiteral()) {
nodeText.removeElement(originalIndex);
diffIndex++;
} else if (removed.isPrimitiveType()) {
if (originalElement.isPrimitive()) {
nodeText.removeElement(originalIndex);
diffIndex++;
} else {
throw new UnsupportedOperationException("removed " + removed.getElement() + " vs " + originalElement);
}
} else if (removed.isWhiteSpace() || removed.getElement() instanceof CsmIndent || removed.getElement() instanceof CsmUnindent) {
diffIndex++;
} else if (originalElement.isWhiteSpace()) {
originalIndex++;
} else if (removed.isChild()) {
// see issue #3721 this case is linked for example to a change of type of variable declarator
nodeText.removeElement(originalIndex);
diffIndex++;
} else {
throw new UnsupportedOperationException("removed " + removed.getElement() + " vs " + originalElement);
}
cleanTheLineOfLeftOverSpace(removedGroup, removed);
}
/**
* Cleans the line of left over space if there is unnecessary indentation and the element will not be replaced
*/
private void cleanTheLineOfLeftOverSpace(RemovedGroup removedGroup, Removed removed) {
if (originalIndex >= originalElements.size()) {
// if all elements were already processed there is nothing to do
return;
}
// we dont want to remove the indentation if the last removed element is a newline
// because in this case we are trying to remove the indentation of the next child element
if (!removedGroup.isProcessed()
&& removedGroup.isLastElement(removed)
&& removedGroup.isACompleteLine()
&& !removed.isNewLine()) {
Integer lastElementIndex = removedGroup.getLastElementIndex();
Optional<Integer> indentation = removedGroup.getIndentation();
if (indentation.isPresent() && !isReplaced(lastElementIndex)) {
for (int i = 0; i < indentation.get(); i++) {
if (originalElements.get(originalIndex).isSpaceOrTab()) {
// If the current element is a space, remove it
nodeText.removeElement(originalIndex);
} else if (originalIndex >= 1 && originalElements.get(originalIndex - 1).isSpaceOrTab()) {
// If the current element is not a space itself we remove the space in front of (before) it
nodeText.removeElement(originalIndex - 1);
originalIndex--;
}
// Remove remaining newline character if needed
if (nodeText.getTextElement(originalIndex).isNewline()) {
nodeText.removeElement(originalIndex);
originalIndex = originalIndex > 0 ? originalIndex-- : 0;
}
}
}
// Mark RemovedGroup as processed
removedGroup.processed();
}
}
// note:
// increment originalIndex if we want to keep the original element
// increment diffIndex if we want to skip the diff element
private void applyKeptDiffElement(Kept kept, TextElement originalElement, boolean originalElementIsChild, boolean originalElementIsToken) {
if (originalElement.isComment()) {
originalIndex++;
} else if (kept.isChild() && ((CsmChild) kept.getElement()).getChild() instanceof Comment) {
diffIndex++;
} else if (kept.isChild() && originalElementIsChild) {
diffIndex++;
originalIndex++;
} else if (kept.isChild() && originalElementIsToken) {
if (originalElement.isWhiteSpaceOrComment()) {
originalIndex++;
} else if (originalElement.isIdentifier() && isNodeWithTypeArguments(kept)) {
diffIndex++;
// skip all token related to node with type argument declaration
// for example:
// List i : in this case originalElement is "List" and the next token is space. There is nothing to skip. in the originalElements list.
// List<String> i : in this case originalElement is "List" and the next token is
// "<" so we have to skip all the tokens which are used in the typed argument declaration [<][String][>](3 tokens) in the originalElements list.
// List<List<String>> i : in this case originalElement is "List" and the next
// token is "<" so we have to skip all the tokens which are used in the typed arguments declaration [<][List][<][String][>][>](6 tokens) in the originalElements list.
int step = getIndexToNextTokenElement((TokenTextElement) originalElement, 0);
originalIndex += step;
originalIndex++;
} else if (originalElement.isIdentifier() && isTypeWithFullyQualifiedName(kept)) {
diffIndex++;
// skip all token related to node with the fully qualified name
// for example:
// java.lang.Object is represented in originalElement as a list of tokens "java", ".", "lang", ".", "Object".
// So we have to skip 5 tokens.
int step = getIndexToNextTokenElement((TokenTextElement) originalElement, kept);
originalIndex += step;
// positioning on the next token
originalIndex++;
} else if ((originalElement.isIdentifier() || originalElement.isKeyword()) && isArrayType(kept)) {
int tokenToSkip = getIndexToNextTokenElementInArrayType((TokenTextElement) originalElement, getArrayLevel(kept));
diffIndex++;
originalIndex += tokenToSkip;
originalIndex++;
} else if (originalElement.isIdentifier()) {
originalIndex++;
diffIndex++;
} else {
if (kept.isPrimitiveType()) {
originalIndex++;
diffIndex++;
} else {
throw new UnsupportedOperationException("kept " + kept.getElement() + " vs " + originalElement);
}
}
} else if (kept.isToken() && originalElementIsToken) {
TokenTextElement originalTextToken = (TokenTextElement) originalElement;
if (kept.getTokenType() == originalTextToken.getTokenKind()) {
originalIndex++;
diffIndex++;
} else if (kept.isNewLine() && originalTextToken.isNewline()) {
originalIndex++;
diffIndex++;
} else if (kept.isNewLine() && originalTextToken.isSpaceOrTab()) {
originalIndex++;
} else if (kept.isWhiteSpaceOrComment()) {
diffIndex++;
} else if (originalTextToken.isWhiteSpaceOrComment()) {
originalIndex++;
} else if (!kept.isNewLine() && originalTextToken.isSeparator()) {
// case where originalTextToken is a separator like ";" and
// kept is not a new line or whitespace for example "}"
// see issue 2351
originalIndex++;
} else {
throw new UnsupportedOperationException("Csm token " + kept.getElement() + " NodeText TOKEN " + originalTextToken);
}
} else if (kept.isToken() && originalElementIsChild) {
diffIndex++;
} else if (kept.isWhiteSpace()) {
diffIndex++;
} else if (kept.isIndent()) {
diffIndex++;
} else if (kept.isUnindent()) {
// Nothing to do
diffIndex++;
} else {
throw new UnsupportedOperationException("kept " + kept.getElement() + " vs " + originalElement);
}
}
/*
* Returns the array level if the DifferenceElement is a CsmChild representing an ArrayType else 0
*/
private int getArrayLevel(DifferenceElement element) {
CsmElement csmElem = element.getElement();
if (isArrayType(element)) {
Node child = ((LexicalDifferenceCalculator.CsmChild) csmElem).getChild();
return ((ArrayType) child).getArrayLevel();
}
return 0;
}
/*
* Returns true if the DifferenceElement is a CsmChild representing an ArrayType
*/
private boolean isArrayType(DifferenceElement element) {
CsmElement csmElem = element.getElement();
return csmElem instanceof LexicalDifferenceCalculator.CsmChild && ((LexicalDifferenceCalculator.CsmChild) csmElem).getChild() instanceof ArrayType;
}
/*
* Returns true if the DifferenceElement is a CsmChild which represents a type with fully qualified name
*/
private boolean isTypeWithFullyQualifiedName(DifferenceElement element) {
if (!element.isChild())
return false;
CsmChild child = (CsmChild) element.getElement();
if (!ClassOrInterfaceType.class.isAssignableFrom(child.getChild().getClass()))
return false;
return ((ClassOrInterfaceType) child.getChild()).getScope().isPresent();
}
/*
* Returns true if the DifferenceElement is a CsmChild with type arguments
*/
private boolean isNodeWithTypeArguments(DifferenceElement element) {
if (!element.isChild())
return false;
CsmChild child = (CsmChild) element.getElement();
if (!NodeWithTypeArguments.class.isAssignableFrom(child.getChild().getClass()))
return false;
Optional<NodeList<Type>> typeArgs = ((NodeWithTypeArguments) child.getChild()).getTypeArguments();
return typeArgs.isPresent() && typeArgs.get().size() > 0;
}
/*
* Try to resolve the number of token to skip in the original list to match
* a ClassOrInterfaceType with a list of tokens like "java", ".", "lang", ".", "Object"
*/
private int getIndexToNextTokenElement(TokenTextElement element, DifferenceElement kept) {
// number of token to skip
int step = 0;
// verify if the DifferenceElement is a ClassOrInterfaceType with a fully qualified name
if (!isTypeWithFullyQualifiedName(kept))
return 0;
CsmChild child = (CsmChild) kept.getElement();
// split the type fully qualified node name to an array of tokens
String[] parts = ((ClassOrInterfaceType) child.getChild()).getNameWithScope().split("\\.");
JavaToken token = element.getToken();
for (String part : parts) {
if (part.equals(token.asString())) {
// get 'dot' token
token = token.getNextToken().get();
if (!token.asString().equals("."))
break;
// get the next part
token = token.getNextToken().get();
step += 2;
continue;
}
// there is no match so we don't have token to skip
step = 0;
break;
}
return step;
}
/*
* Returns the number of tokens to skip in originalElements list to synchronize it with the DiffElements list
* This is due to the fact that types are considered as token in the originalElements list.
* For example,
* List<String> is represented by 4 tokens ([List][<][String][>]) while it's a CsmChild element in the DiffElements list
* So in this case, getIndexToNextTokenElement(..) on the [List] token returns 3 because we have to skip 3 tokens ([<][String][>]) to synchronize
* DiffElements list and originalElements list
* The end of recursivity is reached when there is no next token or if the nested diamond operators are totally managed, to take into account this type of declaration
* List <List<String>> l
* Be careful, this method must be call only if diamond operator could be found in the sequence
*
* @Param TokenTextElement the token currently analyzed
* @Param int the number of nested diamond operators
* @return the number of token to skip in originalElements list
*/
private int getIndexToNextTokenElement(TokenTextElement element, int nestedDiamondOperator) {
// number of token to skip
int step = 0;
Optional<JavaToken> next = element.getToken().getNextToken();
if (!next.isPresent())
return step;
// because there is a token, first we need to increment the number of token to skip
step++;
// manage nested diamond operators by incrementing the level on LT token and decrementing on GT
JavaToken nextToken = next.get();
Kind kind = Kind.valueOf(nextToken.getKind());
if (isDiamondOperator(kind)) {
if (Kind.GT.equals(kind))
nestedDiamondOperator--;
else
nestedDiamondOperator++;
}
// manage the fact where the first token is not a diamond operator but a whitespace
// and the end of the token sequence to skip
// for example in this declaration List <String> a;
if (nestedDiamondOperator == 0 && !nextToken.getCategory().isWhitespace())
return step;
// recursively analyze token to skip
return step += getIndexToNextTokenElement(new TokenTextElement(nextToken), nestedDiamondOperator);
}
/*
* Returns the number of tokens to skip in originalElements list to synchronize it with the DiffElements list
*/
private int getIndexToNextTokenElementInArrayType(TokenTextElement element, int arrayLevel) {
// number of token to skip
int step = 0;
Optional<JavaToken> next = element.getToken().getNextToken();
if (!next.isPresent())
return step;
// because there is a token, first we need to increment the number of token to skip
step++;
// manage array Level by decrementing the level on right bracket token
JavaToken nextToken = next.get();
Kind kind = Kind.valueOf(nextToken.getKind());
if (isBracket(kind)) {
if (Kind.RBRACKET.equals(kind))
arrayLevel--;
}
// manage the fact where the first token is not a diamond operator but a whitespace
// and the end of the token sequence to skip
// for example in this declaration int [] a;
if (arrayLevel == 0 && !nextToken.getCategory().isWhitespace())
return step;
// recursively analyze token to skip
return step += getIndexToNextTokenElementInArrayType(new TokenTextElement(nextToken), arrayLevel);
}
/*
* Returns true if the token is possibly a diamond operator
*/
private boolean isDiamondOperator(Kind kind) {
return Kind.GT.equals(kind) || Kind.LT.equals(kind);
}
/*
* Returns true if the token is a bracket
*/
private boolean isBracket(Kind kind) {
return Kind.LBRACKET.equals(kind) || Kind.RBRACKET.equals(kind);
}
private boolean nextIsRightBrace(int index) {
List<TextElement> elements = originalElements.subList(index, originalElements.size());
for (TextElement element : elements) {
if (!element.isSpaceOrTab()) {
return element.isToken(RBRACE);
}
}
return false;
}
private void applyAddedDiffElement(Added added) {
if (added.isIndent()) {
for (int i = 0; i < STANDARD_INDENTATION_SIZE; i++) {
indentation.add(new TokenTextElement(GeneratedJavaParserConstants.SPACE));
}
addedIndentation = true;
diffIndex++;
return;
}
if (added.isUnindent()) {
for (int i = 0; i < STANDARD_INDENTATION_SIZE && !indentation.isEmpty(); i++) {
indentation.remove(indentation.size() - 1);
}
addedIndentation = false;
diffIndex++;
return;
}
TextElement addedTextElement = added.toTextElement();
boolean used = false;
boolean isPreviousElementNewline = (originalIndex > 0) && originalElements.get(originalIndex - 1).isNewline();
if (isPreviousElementNewline) {
List<TextElement> elements = processIndentation(indentation, originalElements.subList(0, originalIndex - 1));
boolean nextIsRightBrace = nextIsRightBrace(originalIndex);
for (TextElement e : elements) {
if (!nextIsRightBrace && e instanceof TokenTextElement && originalElements.get(originalIndex).isToken(((TokenTextElement) e).getTokenKind())) {
originalIndex++;
} else {
nodeText.addElement(originalIndex++, e);
}
}
} else if (isAfterLBrace(nodeText, originalIndex) && !isAReplacement(diffIndex)) {
if (addedTextElement.isNewline()) {
used = true;
}
nodeText.addElement(originalIndex++, new TokenTextElement(TokenTypes.eolTokenKind()));
// This remove the space in "{ }" when adding a new line
while (originalIndex >= 2 && originalElements.get(originalIndex - 2).isSpaceOrTab()) {
originalElements.remove(originalIndex - 2);
originalIndex--;
}
for (TextElement e : processIndentation(indentation, originalElements.subList(0, originalIndex - 1))) {
nodeText.addElement(originalIndex++, e);
}
// Indentation is painful...
// Sometimes we want to force indentation: this is the case when indentation was expected but
// was actually not there. For example if we have "{ }" we would expect indentation but it is
// not there, so when adding new elements we force it. However if the indentation has been
// inserted by us in this transformation we do not want to insert it again
if (!addedIndentation) {
for (TextElement e : indentationBlock()) {
nodeText.addElement(originalIndex++, e);
}
}
}
if (!used) {
// Handling trailing comments
boolean sufficientTokensRemainToSkip = nodeText.numberOfElements() > originalIndex + 2;
boolean currentIsAComment = nodeText.getTextElement(originalIndex).isComment();
boolean previousIsAComment = originalIndex > 0 && nodeText.getTextElement(originalIndex - 1).isComment();
boolean currentIsNewline = nodeText.getTextElement(originalIndex).isNewline();
boolean isFirstElement = originalIndex == 0;
boolean previousIsWhiteSpace = originalIndex > 0 && nodeText.getTextElement(originalIndex - 1).isWhiteSpace();
boolean commentIsBeforeAddedElement = currentIsAComment && addedTextElement.getRange().isPresent()
&& nodeText.getTextElement(originalIndex).getRange()
.map(range -> range.isBefore(addedTextElement.getRange().get())).orElse(false);
if (sufficientTokensRemainToSkip && currentIsAComment && commentIsBeforeAddedElement) {
// Need to get behind the comment:
// FIXME: Why 2? This comment and the next newline?
originalIndex += 2;
// Defer originalIndex increment
nodeText.addElement(originalIndex, addedTextElement);
// We want to adjust the indentation while considering the new element that we added
originalIndex = adjustIndentation(indentation, nodeText, originalIndex, false);
// Now we can increment
originalIndex++;
} else if (currentIsNewline && previousIsAComment) {
/*
* Manage the case where we want to add an element, after an expression which is followed by a comment on the same line.
* This is not the same case as the one who handles the trailing comments, because in this case the node text element is a new line (not a comment)
* For example : {@code private String a; // this is a }
*/
// Insert after the new line which follows this comment.
originalIndex++;
// We want to adjust the indentation while considering the new element that we added
originalIndex = adjustIndentation(indentation, nodeText, originalIndex, false);
// Defer originalIndex increment
nodeText.addElement(originalIndex, addedTextElement);
// Now we can increment.
originalIndex++;
} else if (currentIsNewline && addedTextElement.isChild()) {
// here we want to place the new child element after the current new line character.
// Except if indentation has been inserted just before this step (in the case where isPreviousElementNewline is true)
// or if the previous character is a space (it could be the case if we want to replace a statement)
// Example 1 : if we insert a statement (a duplicated method call expression ) after this one <code> value();\n\n</code>
// we want to have this result <code> value();\n value();\n</code> not <code> value();\n \nvalue();</code>
// Example 2 : if we want to insert a statement after this one <code> \n</code> we want to have <code> value();\n</code>
// not <code> \nvalue();</code> --> this case appears on member replacement for example
if (!isPreviousElementNewline && !isFirstElement && !previousIsWhiteSpace) {
// Insert after the new line
originalIndex++;
// We want to adjust the indentation while considering the new element that we
// added
originalIndex = adjustIndentation(indentation, nodeText, originalIndex, false);
}
nodeText.addElement(originalIndex, addedTextElement);
originalIndex++;
} else {
nodeText.addElement(originalIndex, addedTextElement);
originalIndex++;
}
}
if (addedTextElement.isNewline()) {
boolean followedByUnindent = isFollowedByUnindent(diffElements, diffIndex);
boolean nextIsRightBrace = nextIsRightBrace(originalIndex);
boolean nextIsNewLine = originalElements.get(originalIndex).isNewline();
if ((!nextIsNewLine && !nextIsRightBrace) || followedByUnindent) {
originalIndex = adjustIndentation(indentation, nodeText, originalIndex, followedByUnindent);
}
}
diffIndex++;
}
/*
* A list iterator which provides a method to know the current positioning
*/
public static class ArrayIterator<T> implements ListIterator<T> {
ListIterator<T> iterator;
public ArrayIterator(List<T> elements) {
this(elements, 0);
}
public ArrayIterator(List<T> elements, int index) {
this.iterator = elements.listIterator(index);
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public T next() {
return iterator.next();
}
@Override
public boolean hasPrevious() {
return iterator.hasPrevious();
}
@Override
public T previous() {
return iterator.previous();
}
@Override
public int nextIndex() {
return iterator.nextIndex();
}
@Override
public int previousIndex() {
return iterator.previousIndex();
}
/*
* Returns the current index in the underlying list
*/
public int index() {
return iterator.nextIndex() - 1;
}
@Override
public void remove() {
iterator.remove();;
}
@Override
public void set(T e) {
iterator.set(e);
}
@Override
public void add(T e) {
iterator.add(e);;
}
}
/*
* Returns true if the next element in the list is an added element of type CsmUnindent
*/
private boolean isFollowedByUnindent(List<DifferenceElement> diffElements, int diffIndex) {
int nextIndexValue = diffIndex + 1;
return (nextIndexValue) < diffElements.size() && diffElements.get(nextIndexValue).isAdded() && diffElements.get(nextIndexValue).getElement() instanceof CsmUnindent;
}
private int adjustIndentation(List<TextElement> indentation, NodeText nodeText, int nodeTextIndex, boolean followedByUnindent) {
List<TextElement> indentationAdj = processIndentation(indentation, nodeText.getElements().subList(0, nodeTextIndex - 1));
if (nodeTextIndex < nodeText.numberOfElements() && nodeText.getTextElement(nodeTextIndex).isToken(RBRACE)) {
indentationAdj = indentationAdj.subList(0, indentationAdj.size() - Math.min(STANDARD_INDENTATION_SIZE, indentationAdj.size()));
} else if (followedByUnindent) {
indentationAdj = indentationAdj.subList(0, Math.max(0, indentationAdj.size() - STANDARD_INDENTATION_SIZE));
}
for (TextElement e : indentationAdj) {
if ((nodeTextIndex < nodeText.numberOfElements()) && nodeText.getTextElement(nodeTextIndex).isSpaceOrTab()) {
nodeTextIndex++;
} else {
nodeText.getElements().add(nodeTextIndex++, e);
}
}
if (nodeTextIndex < 0) {
throw new IllegalStateException();
}
return nodeTextIndex;
}
/*
* Returns true if the current <code>Added</code> element is preceded by a <code>Removed</code> element.
*/
private boolean isAReplacement(int diffIndex) {
return (diffIndex > 0) && diffElements.get(diffIndex).isAdded() && diffElements.get(diffIndex - 1).isRemoved();
}
/*
* Returns true if the current <code>Removed</code> element is followed by a <code>Added</code> element.
*/
private boolean isReplaced(int diffIndex) {
return (diffIndex < diffElements.size() - 1) && diffElements.get(diffIndex + 1).isAdded() && diffElements.get(diffIndex).isRemoved();
}
@Override
public String toString() {
return "Difference{" + diffElements + '}';
}
}