////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.naming;
import java.util.regex.Pattern;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.ScopeUtils;
/**
* <p>
* Checks that local, non-final variable names conform to a format specified
* by the format property. A catch parameter is considered to be
* a local variable. The format is a
* {@link Pattern regular expression}
* and defaults to
* <strong>^[a-z][a-zA-Z0-9]*$</strong>.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="LocalVariableName"/>
* </pre>
* <p>
* An example of how to configure the check for names that begin with a lower
* case letter, followed by letters, digits, and underscores is:
* </p>
* <pre>
* <module name="LocalVariableName">
* <property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/>
* </module>
* </pre>
* <p>
* An example of one character variable name in
* initialization expression(like "i") in FOR loop:
* </p>
* <pre>
* for(int i = 1; i < 10; i++) {}
* </pre>
* <p>
* An example of how to configure the check to allow one char variable name in
* <a href="http://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html">
* initialization expressions</a> in FOR loop:
* </p>
* <pre>
* <module name="LocalVariableName">
* <property name="allowOneCharVarInForLoop" value="true"/>
* </module>
* </pre>
*
* @author Rick Giles
* @author maxvetrenko
*/
public class LocalVariableNameCheck
extends AbstractNameCheck {
/** Regexp for one-char loop variables. */
private static final Pattern SINGLE_CHAR = Pattern.compile("^[a-z]$");
/**
* Allow one character name for initialization expression in FOR loop.
*/
private boolean allowOneCharVarInForLoop;
/** Creates a new {@code LocalVariableNameCheck} instance. */
public LocalVariableNameCheck() {
super("^[a-z][a-zA-Z0-9]*$");
}
/**
* Sets whether to allow one character name in FOR loop or not.
*
* @param allow Flag for allowing or not one character name in FOR loop.
*/
public final void setAllowOneCharVarInForLoop(boolean allow) {
allowOneCharVarInForLoop = allow;
}
@Override
public int[] getDefaultTokens() {
return getAcceptableTokens();
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.VARIABLE_DEF,
};
}
@Override
public int[] getRequiredTokens() {
return getAcceptableTokens();
}
@Override
protected final boolean mustCheckName(DetailAST ast) {
final boolean result;
if (allowOneCharVarInForLoop && isForLoopVariable(ast)) {
final String variableName = ast.findFirstToken(TokenTypes.IDENT).getText();
result = !SINGLE_CHAR.matcher(variableName).find();
}
else {
final DetailAST modifiersAST = ast.findFirstToken(TokenTypes.MODIFIERS);
final boolean isFinal = modifiersAST.branchContains(TokenTypes.FINAL);
result = !isFinal && ScopeUtils.isLocalVariableDef(ast);
}
return result;
}
/**
* Checks if a variable is the loop's one.
* @param variableDef variable definition.
* @return true if a variable is the loop's one.
*/
private static boolean isForLoopVariable(DetailAST variableDef) {
final int parentType = variableDef.getParent().getType();
return parentType == TokenTypes.FOR_INIT
|| parentType == TokenTypes.FOR_EACH_CLAUSE;
}
}