/*
* Copyright 2000-2017 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.plugins.groovy.lang.parser.parsing.util;
import com.intellij.lang.PsiBuilder;
import com.intellij.lang.PsiBuilder.Marker;
import com.intellij.psi.tree.IElementType;
import com.intellij.psi.tree.TokenSet;
import org.jetbrains.plugins.groovy.lang.lexer.GroovyTokenTypes;
/**
* Utility classdef, that contains various useful methods for
* parser needs.
*
* @author ilyas
*/
public abstract class ParserUtils {
/**
* Auxiliary method for strict token appearance
*
* @param builder current builder
* @param elem given element
* @param errorMsg Message, that displays if element was not found; if errorMsg == null nothing displays
* @return true if element parsed
*/
public static boolean getToken(PsiBuilder builder, IElementType elem, String errorMsg) {
if (elem.equals(builder.getTokenType())) {
builder.advanceLexer();
return true;
} else {
if (errorMsg != null)
builder.error(errorMsg);
return false;
}
}
/**
* Auxiliary method for construction like
* <BNF>
* token?
* </BNF>
* parsing
*
* @param builder current builder
* @param elem given element
* @return true if element parsed
*/
public static boolean getToken(PsiBuilder builder, IElementType elem) {
if (elem.equals(builder.getTokenType())) {
builder.advanceLexer();
return true;
}
return false;
}
public static boolean getToken(PsiBuilder builder, IElementType elem1, IElementType elem2) {
Marker marker = builder.mark();
if (getToken(builder, elem1) && getToken(builder, elem2)) {
marker.drop();
return true;
}
else {
marker.rollbackTo();
return false;
}
}
public static boolean getToken(PsiBuilder builder, IElementType element1, TokenSet tokenSet2) {
Marker rb = builder.mark();
if (getToken(builder, element1) && getToken(builder, tokenSet2)) {
rb.drop();
return true;
}
else {
rb.rollbackTo();
return false;
}
}
/**
* Same as simple getToken() method but with TokenSet
*
* @param builder
* @param tokenSet
* @return
*/
public static boolean getToken(PsiBuilder builder, TokenSet tokenSet) {
return getToken(builder, tokenSet, null);
}
/**
* Same as simple getToken() method but with TokenSet
*
* @param builder
* @param tokenSet
* @return
*/
public static boolean getToken(PsiBuilder builder, TokenSet tokenSet, String msg) {
if (tokenSet.contains(builder.getTokenType())) {
builder.advanceLexer();
return true;
}
else {
if (msg != null) {
builder.error(msg);
}
return false;
}
}
/**
* Checks, that following element sequence is like given
*
* @param builder Given PsiBuilder
* @param elems Array of need elements in order
* @return true if following sequence is like a given
*
* Note don't change type of last parameter to "IElementType... elems"! Passed array should be stored in static variable to avoid creation
* of new array.
*/
public static boolean lookAhead(PsiBuilder builder, IElementType[] elems) {
if (elems[0] != builder.getTokenType()) return false;
if (elems.length == 1) return true;
Marker rb = builder.mark();
builder.advanceLexer();
int i = 1;
while (!builder.eof() && i < elems.length && elems[i] == builder.getTokenType()) {
builder.advanceLexer();
i++;
}
rb.rollbackTo();
return i == elems.length;
}
public static boolean lookAhead(PsiBuilder builder, IElementType element1) {
return element1 == builder.getTokenType();
}
public static boolean lookAhead(PsiBuilder builder, IElementType element1, IElementType element2) {
if (element1 != builder.getTokenType()) return false;
Marker rb = builder.mark();
builder.advanceLexer();
boolean res = (!builder.eof() && element2 == builder.getTokenType());
rb.rollbackTo();
return res;
}
public static boolean lookAhead(PsiBuilder builder, IElementType element1, IElementType element2, IElementType element3) {
if (element1 != builder.getTokenType()) return false;
Marker rb = builder.mark();
boolean res = false;
builder.advanceLexer();
if (!builder.eof() && element2 == builder.getTokenType()) {
builder.advanceLexer();
res = (!builder.eof() && element3 == builder.getTokenType());
}
rb.rollbackTo();
return res;
}
public static boolean lookAhead(PsiBuilder builder, IElementType element1, TokenSet tokenSet) {
Marker rb = builder.mark();
boolean result = getToken(builder, element1) && getToken(builder, tokenSet);
rb.rollbackTo();
return result;
}
public static boolean lookAhead(PsiBuilder builder, IElementType element1, IElementType element2, IElementType element3, IElementType element4) {
if (element1 != builder.getTokenType()) return false;
Marker rb = builder.mark();
boolean res = false;
builder.advanceLexer();
if (!builder.eof() && element2 == builder.getTokenType()) {
builder.advanceLexer();
if (!builder.eof() && element3 == builder.getTokenType()) {
builder.advanceLexer();
res = (!builder.eof() && element4 == builder.getTokenType());
}
}
rb.rollbackTo();
return res;
}
/**
* Wraps current token to node with specified element type
*
* @param builder Given builder
* @param elem Node element
* @return elem type
*/
public static IElementType eatElement(PsiBuilder builder, IElementType elem) {
Marker marker = builder.mark();
builder.advanceLexer();
marker.done(elem);
return elem;
}
/**
* Wraps current token with error message
*
* @param builder
* @param msg Error message
*/
public static void wrapError(PsiBuilder builder, String msg) {
Marker marker = builder.mark();
builder.advanceLexer();
marker.error(msg);
}
public static boolean skipCountingBraces(PsiBuilder builder, TokenSet until) {
int braceLevel = 0;
while (true) {
if (builder.eof()) {
return false;
}
final IElementType type = builder.getTokenType();
if (braceLevel == 0 && until.contains(type)) {
return true;
}
if (GroovyTokenTypes.mLCURLY == type) {
braceLevel++;
}
else if (GroovyTokenTypes.mRCURLY == type) {
braceLevel--;
}
builder.advanceLexer();
}
}
}