eu.mihosoft.vmf.vmftext.ParseTreeUtil Maven / Gradle / Ivy
/*
* Copyright 2017-2018 Michael Hoffer . All rights reserved.
* Copyright 2017-2018 Goethe Center for Scientific Computing, University Frankfurt. All rights reserved.
*
* 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.
*
* If you use this software for scientific research then please cite the following publication(s):
*
* M. Hoffer, C. Poliwoda, & G. Wittum. (2013). Visual reflection library:
* a framework for declarative GUI programming on the Java platform.
* Computing and Visualization in Science, 2013, 16(4),
* 181–192. http://doi.org/10.1007/s00791-014-0230-y
*/
package eu.mihosoft.vmf.vmftext;
import eu.mihosoft.vmf.vmftext.grammar.CodeLocation;
import eu.mihosoft.vmf.vmftext.grammar.CodeRange;
import eu.mihosoft.vmf.vmftext.grammar.antlr4.ANTLRv4Parser;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.Token;
/**
* Utility class for ANTLR4 parse trees. The utility methods provided by this class are
* mostly useful for determining the type of specified element contexts.
*
* @author Michael Hoffer
*/
public class ParseTreeUtil {
private ParseTreeUtil() {
throw new AssertionError("Don't instantiate me!");
}
/**
* Indicates whether the specified element context is a rule block.
* @param e the element context to check
* @return {@code true} if the specified context is a rule block; {@code false} otherwise
*/
public static boolean isRuleBlock(ANTLRv4Parser.ElementContext e) {
return e.labeledElement().atom()== null && e.labeledElement().block()!=null;
}
/**
* Indicates whether the specified element context is a parser rule.
* @param e the element context to check
* @return {@code true} if the specified celement ontext is a parser rule; {@code false} otherwise
*/
public static boolean isParserRule(ANTLRv4Parser.ElementContext e) {
if(e.labeledElement() == null || e.labeledElement().atom()==null) return false;
return e.labeledElement().atom().ruleref() != null;
}
/**
* Indicates whether the specified element context is a lexer rule.
* @param e the element context to check
* @return {@code true} if the specified element context is a lexer rule; {@code false} otherwise
*/
public static boolean isLexerRule(ANTLRv4Parser.ElementContext e) {
if(e.labeledElement()!=null && e.labeledElement().atom()!=null) {
String atomText = e.labeledElement().atom().getText();
// detect lexer rules with not operator
if(atomText.length()> 1
&& atomText.startsWith("~")
&& Character.isUpperCase(atomText.codePointAt(1)))
return true;
}
if(e.labeledElement() == null || e.labeledElement().atom()==null) return false;
return e.labeledElement().atom().terminal() != null &&
e.labeledElement().atom().terminal().TOKEN_REF() != null;
}
/**
* Indicates whether the specified element context is a string literal.
* @param e the element context to check
* @return {@code true} if the specified element context is a string literal; {@code false} otherwise
*/
public static boolean isStringLiteral(ANTLRv4Parser.ElementContext e) {
if(e.labeledElement()!=null && e.labeledElement().atom()!=null) {
String atomText = e.labeledElement().atom().getText();
// detect literals with not operator
if(atomText.startsWith("~'")) return true;
}
if(e.labeledElement() == null || e.labeledElement().atom()==null) return false;
return e.labeledElement().atom().terminal() != null &&
e.labeledElement().atom().terminal().TOKEN_REF() == null;
}
/**
* Indicates whether the specified element context is negated, i.e. {@code ~[ABC]}
* @param e the element context to check
* @return {@code true} if the specified element context is negated; {@code false} otherwise
*/
public static boolean isNegated(ANTLRv4Parser.ElementContext e) {
if(isParserRule(e)) {
// parser rules can't be negated
return false;
} else if(e.atom()!=null) {
return e.atom().notSet()!=null;
} else if(e.labeledElement()!=null && e.labeledElement().atom()!=null) {
return e.labeledElement().atom().notSet()!=null;
}
return false;
}
/**
* Returns the text of the specified element context.
* @param e element context
* @return the text of the specified element context
*/
public static String getElementText(ANTLRv4Parser.ElementContext e) {
if(isParserRule(e)) {
return e.labeledElement().atom().ruleref().getText();
} else if(isLexerRule(e)) {
if(e.labeledElement().atom()!=null) {
return e.labeledElement().atom().getText();
}
/*else {
// default case
return e.labeledElement().atom().terminal().TOKEN_REF().getText();
}*/
} else if(isStringLiteral(e)) {
if(e.labeledElement().atom()!=null) {
return e.labeledElement().atom().getText();
}
/*else {
// default case
return e.labeledElement().atom().terminal().STRING_LITERAL().getText();
}*/
}
return null;
}
/**
* Indicates whether the specified element context is labelled.
* @param e the element context to check
* @return {@code true} if the specified element context is labeled; {@code false} otherwise
*/
public static boolean isLabeledElement(ANTLRv4Parser.ElementContext e) {
return e.labeledElement() != null && e.labeledElement().identifier() != null;
}
/**
* Returns the start location of the specified token.
* @param t token
* @return the start location of the specified token
*/
public static CodeLocation tokenToCodeLocationStart(Token t) {
return CodeLocation.newBuilder().
withIndex(t.getStartIndex()).
withCharPosInLine(t.getCharPositionInLine()).withLine(t.getLine()).build();
}
/**
* Returns the stop/end location of the specified token.
* @param t token
* @param ctx parser rule context the token belongs to
* @return the stop/end location of the specified token
*/
public static CodeLocation tokenToCodeLocationStop(Token t, ParserRuleContext ctx) {
int startIndex = t.getStartIndex();
int stopIndex = t.getStopIndex();
int diff = stopIndex - startIndex;
return CodeLocation.newBuilder().
withIndex(stopIndex).
withCharPosInLine(t.getCharPositionInLine()+diff).
withLine(/*TODO 14.02.2018 does not work for multi-line-tokens*/t.getLine()).build();
}
/**
* Returns the code range of the specified context.
* @param ctx the context to check
* @return the code range of the specified context
*/
public static CodeRange ctxToCodeRange(ParserRuleContext ctx) {
// consider for stop line: https://stackoverflow.com/a/17487805
CodeLocation start = tokenToCodeLocationStart(ctx.start);
CodeLocation stop = tokenToCodeLocationStart(ctx.stop);
return CodeRange.newBuilder().withStart(start).
withStop(tokenToCodeLocationStop(ctx.stop,ctx))
.withLength(stop.getIndex()-start.getIndex()+1/*+1 because of inclusive vs. exclusive*/).build();
}
/**
* Indicates whether the specified element context is a labeled block element.
* @param e element context to check
* @return {@code true} if the specified element context is a labeled block element; {@code false} otherwise
*/
public static boolean isLabeledBlockElement(ANTLRv4Parser.ElementContext e) {
return isLabeledElement(e) && e.labeledElement().block()!=null;
}
/**
* Indicates whether the specified element context is a block element.
* @param e element context to check
* @return {@code true} if the specified element context is a block element; {@code false} otherwise
*/
public static boolean isBlockElement(ANTLRv4Parser.ElementContext e) {
return e.labeledElement()!=null && e.labeledElement().block()!=null;
}
/**
* Indicates whether the specified element context is an unlabeled block element.
* @param e element context to check
* @return {@code true} if the specified element context is an unlabeled block element; {@code false} otherwise
*/
public static boolean isUnlabeledBlockElement(ANTLRv4Parser.ElementContext e) {
return e.labeledElement()!=null && !isLabeledElement(e) && e.labeledElement().block()!=null;
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy