CSTPrinter.java
/*
* Portions of this software was developed by employees of the National Institute
* of Standards and Technology (NIST), an agency of the Federal Government and is
* being made available as a public service. Pursuant to title 17 United States
* Code Section 105, works of NIST employees are not subject to copyright
* protection in the United States. This software may be subject to foreign
* copyright. Permission in the United States and in foreign countries, to the
* extent that NIST may hold copyright, to use, copy, modify, create derivative
* works, and distribute this software and its documentation without fee is hereby
* granted on a non-exclusive basis, provided that this notice and disclaimer
* of warranty appears in all copies.
*
* THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
* EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
* THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
* INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
* SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE. IN NO EVENT
* SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
* INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
* OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
* CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
* PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
* OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
*/
package gov.nist.secauto.metaschema.core.metapath;
import gov.nist.secauto.metaschema.core.metapath.antlr.metapath10Parser;
import gov.nist.secauto.metaschema.core.util.ObjectUtils;
import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.RuleContext;
import org.antlr.v4.runtime.tree.ParseTree;
import java.io.PrintStream;
import java.util.List;
import edu.umd.cs.findbugs.annotations.NonNull;
class CSTPrinter {
@NonNull
private final PrintStream outputStream;
private boolean ignoringWrappers = true;
/**
* Construct a new concrete syntax tree (CST) printer.
*
* @param outputStream
* the stream to print to
*/
public CSTPrinter(@NonNull PrintStream outputStream) {
this.outputStream = ObjectUtils.requireNonNull(outputStream, "outputStream");
}
/**
* Set the behavior for handling wrapper nodes in the CST hierarchy.
*
* @param ignoringWrappers
* {@code true} if wrappers should be ignored or {@code false}
* otherwise
*/
public void setIgnoringWrappers(boolean ignoringWrappers) {
this.ignoringWrappers = ignoringWrappers;
}
/**
* Print a given CST {@link RuleContext} node.
*
* @param ctx
* the CST node
*/
public void print(@NonNull RuleContext ctx) {
explore(ctx, 0);
}
/**
* Print a given CST {@link ParseTree} using the provided {@code ruleNames}.
*
* @param tree
* the CST parse tree
* @param ruleNames
* the list of rule names to use for human readability
*/
public void print(ParseTree tree, List<String> ruleNames) {
explore((RuleContext) tree.getPayload(), 0);
}
private void explore(RuleContext ctx, int indentation) {
boolean toBeIgnored = ignoringWrappers && ctx.getChildCount() == 1 && ctx.getChild(0) instanceof ParserRuleContext;
String ruleName = metapath10Parser.ruleNames[ctx.getRuleIndex()];
for (int i = 0; i < indentation; i++) {
outputStream.print(" ");
}
outputStream.print(ruleName);
if (toBeIgnored) {
outputStream.print("(ignored)");
}
outputStream.print(": ");
outputStream.print(ctx.getText());
outputStream.println();
for (int i = 0; i < ctx.getChildCount(); i++) {
ParseTree element = ctx.getChild(i);
if (element instanceof RuleContext) {
explore((RuleContext) element, indentation + 1);
}
}
}
}