PPPatternHelper.java

/**
 * Copyright (c) 2011 Cloudsmith Inc. and other contributors, as listed below.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *   Cloudsmith
 * 
 */
package org.cloudsmith.geppetto.pp.dsl.validation;

import java.util.regex.Pattern;

import com.google.inject.Inject;
import com.google.inject.Singleton;

/**
 * Helper patterns for puppet
 * (hint: http://www.regexplanet.com/simple/index.html for interactive testing of java regex).
 * 
 */
// terminal NAME : ('0'..'9' | 'a'..'z') EXT_WORD_CHAR* ;
// terminal CLASS_NAME : (('a'..'z') EXT_WORD_CHAR*)? ('::' ('a'..'z') EXT_WORD_CHAR*)+;
// terminal CLASS_REF: ('::'? ('A'..'Z') EXT_WORD_CHAR*)+ ;
//
// terminal fragment EXT_WORD_CHAR : WORD_CHAR | '-' ;
// terminal fragment EXT_WORD_CHAR_NUM : EXT_WORD_CHAR | '-' | '.'; // to allow decimals 0.0E-2 as a name, hex is already ok 0x0aef
// terminal fragment WORD_CHAR : ('0'..'9')|('a'..'z')|('A'..'Z')|'_';

@Singleton
public class PPPatternHelper {

	protected final Pattern namePattern;

	protected final Pattern classRefPattern;

	protected final Pattern classNamePattern;

	protected final Pattern regexpPattern;

	protected final Pattern variablePattern;

	protected final Pattern sqStringPattern;

	protected final Pattern unrecognizedSQEscapes;

	protected final Pattern recognizedSQEscapes;

	protected final Pattern unrecognizedDQEscapes;

	protected final Pattern recognizedDQEscapes;

	protected final Pattern decimalVarPattern;

	/**
	 * Intended as Ruby %r{[\w-]} equivalence
	 */
	private static final String EXT_WORD_CHAR = "[0-9a-zA-Z_\\.-]";

	/**
	 * Intended as Ruby %r{-[\w]} equivalence
	 */
	private static final String WORD_CHAR = "[0-9a-zA-Z_-]";

	/**
	 * No '-' allowed in variables.
	 */
	private static final String VAR_CHAR = "[0-9a-zA-Z_]";

	@Inject
	public PPPatternHelper() {
		namePattern = Pattern.compile("[0-9a-z]" + EXT_WORD_CHAR + "*");
		classRefPattern = Pattern.compile("((::)?[A-Z]" + WORD_CHAR + "*)+");
		classNamePattern = Pattern.compile("([a-z]" + WORD_CHAR + "*)?(::[a-z]" + WORD_CHAR + "*)*");

		// regexp may not:
		// be empty - '//'
		// start with a * - '/*...'
		// contain newline character
		regexpPattern = Pattern.compile("/([^/\\n\\*\\\\]|(\\\\[^\\n]))([^/\\n\\\\]|(\\\\[^\\n]))*/[a-z]*");
		variablePattern = Pattern.compile("\\$(::)?(" + VAR_CHAR + "+::)*" + VAR_CHAR + "+");

		// sq string may not contain unescaped single quote
		sqStringPattern = Pattern.compile("([^'\\\\]|\\\\.)*");

		unrecognizedSQEscapes = Pattern.compile("\\\\[^stn '\"\\\\\\r\\n]");

		recognizedSQEscapes = Pattern.compile("\\\\[\\\\nrst'\" ]");

		unrecognizedDQEscapes = Pattern.compile("\\\\[^stn '\"\\\\\\r\\n\\$]");

		recognizedDQEscapes = Pattern.compile("\\\\[\\\\nrst'\" \\$]");

		decimalVarPattern = Pattern.compile("\\$?([0]|([1-9][0-9]*))");
	}

	/**
	 * For DQ string
	 * 
	 * @return
	 */
	public Pattern getRecognizedDQEscapePattern() {
		return recognizedDQEscapes;
	}

	/**
	 * For SQ string
	 * 
	 * @return
	 */
	public Pattern getRecognizedSQEscapePattern() {
		return recognizedSQEscapes;
	}

	/**
	 * Finds unrecognized escapes if recognized escapes have been removed from the input first.
	 * For DQ string.
	 * 
	 * @return
	 */
	public Pattern getUnrecognizedDQEscapesPattern() {
		return unrecognizedDQEscapes;
	}

	/**
	 * Finds unrecognized escapes if recognized escapes have been removed from the input first.
	 * For SQ string.
	 * 
	 * @return
	 */
	public Pattern getUnrecognizedSQEscapesPattern() {
		return unrecognizedSQEscapes;
	}

	public boolean isCLASSNAME(String s) {
		if(s == null || s.length() == 0)
			return false;
		return classNamePattern.matcher(s).matches() && !s.contains(":::");
	}

	public boolean isCLASSREF(String s) {
		if(s == null || s.length() == 0)
			return false;
		return classRefPattern.matcher(s).matches() && !s.contains(":::");
	}

	public boolean isDECIMALVAR(String s) {
		if(s == null || s.length() == 0)
			return false;
		return decimalVarPattern.matcher(s).matches();
	}

	public boolean isNAME(String s) {
		if(s == null || s.length() == 0)
			return false;
		return namePattern.matcher(s).matches() && !s.contains(":::");
	}

	public boolean isREGEXP(String s) {
		if(s == null || s.length() == 0)
			return false;
		return regexpPattern.matcher(s).matches();
	}

	/**
	 * Checks the content *between* ' ' (i.e. do not include the quotes in the given input).
	 * 
	 * @param s
	 * @return
	 */
	public boolean isSQSTRING(String s) {
		if(s == null || s.length() == 0)
			return true; // ok if empty
		// return sqStringPattern.matcher(s).matches();

		boolean escaped = false;
		for(int i = 0; i < s.length(); i++) {
			switch(s.charAt(i)) {
				case '\\':
					escaped = !escaped;
					break;
				case '\'':
					if(!escaped)
						return false;
					escaped = false;
					break;
				default:
					escaped = false;
			}
		}
		return true;
	}

	public boolean isVARIABLE(String s) {
		if(s == null || s.length() == 0)
			return false;
		return variablePattern.matcher(s).matches();
	}
}