Artifact
52409b009e75e16f9bc945948f00b28466764910:
/*
* TclBoolean.java
*
* Copyright (c) 1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and
* redistribution of this file, and for a DISCLAIMER OF ALL
* WARRANTIES.
*
* RCS: @(#) $Id: TclBoolean.java,v 1.9 2006/06/13 06:52:47 mdejong Exp $
*
*/
package tcl.lang;
/**
* This class implements the boolean object type in Tcl.
*/
public class TclBoolean implements InternalRep {
/**
* Internal representations for all TclBooleans.
*/
private final static TclBoolean trueRep = new TclBoolean(true);
private final static TclBoolean falseRep = new TclBoolean(false);
private final boolean value;
/**
* Construct a TclBoolean representation with the given boolean value.
* Note that only two TclBoolean internal rep instances will ever
* exist.
*
* @param b initial boolean value.
*/
private TclBoolean(boolean b) {
value = b;
}
/**
* Returns a dupilcate of the current object.
*/
public InternalRep duplicate() {
return this;
}
/**
* Implement this no-op for the InternalRep interface.
*/
public void dispose() {}
/**
* Called to query the string representation of the Tcl object. This
* method is called only by TclObject.toString() when
* TclObject.stringRep is null.
*
* @return the string representation of the Tcl object.
*/
public String toString() {
if (value) {
return "1";
} else {
return "0";
}
}
/**
* Creates a new instance of a TclObject with a TclBoolean internal
* representation.
*
* @param b initial value of the boolean object.
* @return the TclObject with the given boolean value.
*/
public static TclObject newInstance(boolean b) {
return new TclObject(b ? trueRep : falseRep);
}
/**
* SetBooleanFromAny -> setBooleanFromAny
*
* Called to convert the other object's internal rep to boolean.
*
* @param interp current interpreter.
* @param tobj the TclObject to convert to use the
* representation provided by this class.
*/
private static void setBooleanFromAny(Interp interp, TclObject tobj)
throws TclException {
// Get the string representation. Make it up-to-date if necessary.
String string = tobj.toString();
if (tobj.isIntType()) {
int i = TclInteger.get(interp, tobj);
if (i == 0) {
tobj.setInternalRep(falseRep);
} else {
tobj.setInternalRep(trueRep);
}
if (TclObject.saveObjRecords) {
String key = "TclInteger -> TclBoolean";
Integer num = (Integer) TclObject.objRecordMap.get(key);
if (num == null) {
num = new Integer(1);
} else {
num = new Integer(num.intValue() + 1);
}
TclObject.objRecordMap.put(key, num);
}
} else if (tobj.isDoubleType()) {
double d = TclDouble.get(interp, tobj);
if (d == 0.0) {
tobj.setInternalRep(falseRep);
} else {
tobj.setInternalRep(trueRep);
}
if (TclObject.saveObjRecords) {
String key = "TclDouble -> TclBoolean";
Integer num = (Integer) TclObject.objRecordMap.get(key);
if (num == null) {
num = new Integer(1);
} else {
num = new Integer(num.intValue() + 1);
}
TclObject.objRecordMap.put(key, num);
}
} else {
// Copy the string converting its characters to lower case.
string = string.toLowerCase();
String lowerCase = string.toLowerCase();
// Parse the string as a boolean. We use an implementation here that
// doesn't report errors in interp if interp is null.
boolean b;
boolean badBoolean = false;
try {
b = Util.getBoolean(interp, lowerCase);
} catch (TclException te) {
// Boolean values can be extracted from ints or doubles. Note
// that we don't use strtoul or strtoull here because we don't
// care about what the value is, just whether it is equal to
// zero or not.
badBoolean = true;
b = false; // Always reassigned below
if (interp != null) {
interp.resetResult();
}
try {
b = (Util.getInt(interp, lowerCase) != 0);
badBoolean = false;
} catch (TclException te2) {}
if (badBoolean) {
try {
b = (Util.getDouble(interp, lowerCase) != 0.0);
badBoolean = false;
} catch (TclException te2) {}
}
}
if (badBoolean) {
if (interp != null) {
interp.resetResult();
}
throw new TclException(interp,
"expected boolean value but got \"" +
string + "\"");
}
if (b) {
tobj.setInternalRep(trueRep);
} else {
tobj.setInternalRep(falseRep);
}
if (TclObject.saveObjRecords) {
String key = "TclString -> TclBoolean";
Integer num = (Integer) TclObject.objRecordMap.get(key);
if (num == null) {
num = new Integer(1);
} else {
num = new Integer(num.intValue() + 1);
}
TclObject.objRecordMap.put(key, num);
}
}
}
/**
* Returns the value of the object as an boolean.
*
* An object with a TclBoolean internal rep has
* a boolean value. An object with a TclInteger
* internal rep and has the int value "0" or "1"
* is also a valid boolean value.
*
* @param interp current interpreter.
* @param tobj the TclObject to use as an boolean.
* @return the boolean value of the object.
* @exception TclException if the object cannot be converted into a
* boolean.
*/
public static boolean get(
final Interp interp,
final TclObject tobj)
throws TclException
{
if (tobj.isIntType()) {
// An integer with the value 0 or 1 can be
// considered a boolean value, so there is
// no need to change the internal rep.
int ival = tobj.ivalue; // Inline TclInteger.get()
if (ival == 0) {
return false;
} else if (ival == 1) {
return true;
}
}
InternalRep rep = tobj.getInternalRep();
TclBoolean tbool;
if (!(rep instanceof TclBoolean)) {
setBooleanFromAny(interp, tobj);
tbool = (TclBoolean) tobj.getInternalRep();
} else {
tbool = (TclBoolean) rep;
}
return tbool.value;
}
}