/*****************************************************************************
SQLJEP - Java SQL Expression Parser 0.2
November 1 2006
(c) Copyright 2006, Alexey Gaidukov
SQLJEP Author: Alexey Gaidukov
SQLJEP is based on JEP 2.24 (http://www.singularsys.com/jep/)
(c) Copyright 2002, Nathan Funk
See LICENSE.txt for license information.
*****************************************************************************/
package com.meidusa.amoeba.sqljep.function;
import com.meidusa.amoeba.sqljep.function.PostfixCommand;
import com.meidusa.amoeba.sqljep.ASTFunNode;
import com.meidusa.amoeba.sqljep.JepRuntime;
import com.meidusa.amoeba.sqljep.ParseException;
public class Instr extends PostfixCommand {
private static final String PARAM_EXCEPTION = "BeginIndex and Number in instr shoud be integers";
private static final String OUT_OF_RANGE_EXCEPTION = "The fourth argument of instr is out of range";
final public int getNumberOfParameters() {
return -1;
}
public Comparable<?>[] evaluate(ASTFunNode node, JepRuntime runtime) throws ParseException {
node.childrenAccept(runtime.ev, null);
int num = node.jjtGetNumChildren();
if (num == 2 || num ==3 || num ==4) {
Comparable<?>[] comparables= new Comparable<?>[num];
for(int i= num-1;i<=0;i--){
comparables[i] = runtime.stack.pop();
}
return comparables;
} else {
removeParams(runtime.stack, num);
throw new ParseException(PARAMS_NUMBER+" for instr");
}
}
public static Integer instr(Comparable<?> param1, Comparable<?> param2) {
if (param1 == null || param2 == null) {
return null;
}
return new Integer(param1.toString().indexOf(param2.toString())+1);
}
public static Integer instr(Comparable<?> param1, Comparable<?> param2, Comparable<?> param3) throws ParseException {
if (param1 == null || param2 == null || param3 == null) {
return null;
}
int beginIndex;
try {
beginIndex = getInteger(param3)-1;
} catch (ParseException e) {
throw new ParseException(PARAM_EXCEPTION);
}
String source = param1.toString();
if (beginIndex < 0) {
beginIndex += source.length()+1;
return new Integer(source.lastIndexOf(param2.toString(), beginIndex)+1);
} else {
return new Integer(source.indexOf(param2.toString(), beginIndex)+1);
}
}
public static Integer instr(Comparable<?> param1, Comparable<?> param2, Comparable<?> param3, Comparable<?> param4) throws ParseException {
if (param1 == null || param2 == null || param3 == null || param4 == null) {
return null;
}
int beginIndex;
int number;
String source = param1.toString();
try {
beginIndex = getInteger(param3)-1;
number = getInteger(param4);
} catch (ParseException e) {
throw new ParseException(PARAM_EXCEPTION);
}
if (number < 1) {
throw new ParseException(OUT_OF_RANGE_EXCEPTION);
}
int i = 0;
if (beginIndex < 0) {
beginIndex += source.length()+1;
for (; number > 0 && i >= 0; number--) {
i = source.lastIndexOf(param2.toString(), beginIndex);
beginIndex = i-1;
}
} else {
for (; number > 0 && i >= 0; number--) {
i = source.indexOf(param2.toString(), beginIndex);
beginIndex = i+1;
}
}
return new Integer(i+1);
}
public Comparable<?> getResult(Comparable<?>... comparables)
throws ParseException {
if(comparables.length == 2){
return instr(comparables[0],comparables[1]);
}else if(comparables.length == 3){
return instr(comparables[0],comparables[1],comparables[2]);
}else{
return instr(comparables[0],comparables[1],comparables[2],comparables[3]);
}
}
}