Tcl Source Code

 */

/*
 * The structure used for the ArithSeries internal representation.
 * Note that the len can in theory be always computed by start,end,step
 * but it's faster to cache it inside the internal representation.
 */

typedef struct {
    Tcl_Size len;
    Tcl_Obj **elements;
    int isDouble;
} ArithSeries;

typedef struct {
    ArithSeries base;
    Tcl_WideInt start;
    Tcl_WideInt end;
    Tcl_WideInt step;
} ArithSeriesInt;

typedef struct {



    ArithSeries base;
    double start;
    double end;
    double step;
    unsigned precision;		/* Number of decimal places to render. */
} ArithSeriesDbl;

/* Forward declarations. */

static int		TclArithSeriesObjIndex(TCL_UNUSED(Tcl_Interp *),




			    Tcl_Obj *arithSeriesObj, Tcl_Size index,
			    Tcl_Obj **elemObj);

static Tcl_Size		ArithSeriesObjLength(Tcl_Obj *arithSeriesObj);
static int		TclArithSeriesObjRange(Tcl_Interp *interp,
			    Tcl_Obj *arithSeriesObj, Tcl_Size fromIdx,
			    Tcl_Size toIdx, Tcl_Obj **newObjPtr);
static int		TclArithSeriesObjReverse(Tcl_Interp *interp,
			    Tcl_Obj *arithSeriesObj, Tcl_Obj **newObjPtr);
static int		TclArithSeriesGetElements(Tcl_Interp *interp,
			    Tcl_Obj *objPtr, Tcl_Size *objcPtr,
			    Tcl_Obj ***objvPtr);
static void		DupArithSeriesInternalRep(Tcl_Obj *srcPtr,
			    Tcl_Obj *copyPtr);
static void		FreeArithSeriesInternalRep(Tcl_Obj *arithSeriesObjPtr);
static void		UpdateStringOfArithSeries(Tcl_Obj *arithSeriesObjPtr);
static int		SetArithSeriesFromAny(Tcl_Interp *interp,
			    Tcl_Obj *objPtr);
static int		ArithSeriesInOperation(Tcl_Interp *interp,
			    Tcl_Obj *valueObj, Tcl_Obj *arithSeriesObj,
			    int *boolResult);
static int		TclArithSeriesObjStep(Tcl_Obj *arithSeriesObj,
			    Tcl_Obj **stepObj);

/* ------------------------ ArithSeries object type -------------------------- */

static const Tcl_ObjType arithSeriesType = {
    "arithseries",			/* name */
    FreeArithSeriesInternalRep,		/* freeIntRepProc */
    DupArithSeriesInternalRep,		/* dupIntRepProc */
    UpdateStringOfArithSeries,		/* updateStringProc */
    SetArithSeriesFromAny,		/* setFromAnyProc */
    TCL_OBJTYPE_V2(
    ArithSeriesObjLength,
    TclArithSeriesObjIndex,
    TclArithSeriesObjRange,
    TclArithSeriesObjReverse,
    TclArithSeriesGetElements,
    NULL, // SetElement
    NULL, // Replace
    ArithSeriesInOperation) // "in" operator
};

/*
 * Helper functions
 *
 * - power10 -- Fast version of pow(10, (int) n) for common cases.
 * - ArithRound -- Round doubles to the number of significant fractional
 *                 digits
 * - ArithSeriesIndexDbl -- base list indexing operation for doubles
 * - ArithSeriesIndexInt --   "    "      "        "      "  integers
 * - ArithSeriesGetInternalRep -- Return the internal rep from a Tcl_Obj
 * - Precision -- determine the number of factional digits for the given
 *   double value
 * - maxPrecision -- Using the values provide, determine the longest percision
 *   in the arithSeries
 */

static inline double
power10(
    unsigned n)
{
    static const double powers[] = {
	1, 10, 100, 1000, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, 1e12,
	1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19, 1e20
    };

    if (n < sizeof(powers) / sizeof(*powers)) {
	return powers[n];
    } else {
	// Not an expected case. Doesn't need to be so fast
	return pow(10, n);
    }
}

static inline double
ArithRound(
    double d,
    unsigned n)
{
    double scalefactor = power10(n);
    return round(d * scalefactor) / scalefactor;
}

static inline double
ArithSeriesIndexDbl(
    ArithSeries *arithSeriesRepPtr,
    Tcl_WideInt index)
{

    if (arithSeriesRepPtr->isDouble) {
	ArithSeriesDbl *dblRepPtr = (ArithSeriesDbl *) arithSeriesRepPtr;
	double d = dblRepPtr->start + (index * dblRepPtr->step);

	return ArithRound(d, dblRepPtr->precision);
    } else {
	ArithSeriesInt *intRepPtr = (ArithSeriesInt *) arithSeriesRepPtr;
	return (double)(intRepPtr->start + (index * intRepPtr->step));
    }
}

static inline Tcl_WideInt
ArithSeriesIndexInt(
    ArithSeries *arithSeriesRepPtr,
    Tcl_WideInt index)
{

    if (arithSeriesRepPtr->isDouble) {
	ArithSeriesDbl *dblRepPtr = (ArithSeriesDbl *) arithSeriesRepPtr;
	return (Tcl_WideInt) (dblRepPtr->start + (index * dblRepPtr->step));
    } else {
	ArithSeriesInt *intRepPtr = (ArithSeriesInt *) arithSeriesRepPtr;
	return intRepPtr->start + (index * intRepPtr->step);
    }
}

static inline ArithSeries *
ArithSeriesGetInternalRep(
    Tcl_Obj *objPtr)
{
    const Tcl_ObjInternalRep *irPtr = TclFetchInternalRep(objPtr,
	    &arithSeriesType);
    return irPtr ? (ArithSeries *) irPtr->twoPtrValue.ptr1 : NULL;
}

/*
 * Compute number of significant fractional digits
 */
static inline unsigned
Precision(
    double d)
{
    char tmp[TCL_DOUBLE_SPACE + 2], *off;

    tmp[0] = 0;
    Tcl_PrintDouble(NULL, d, tmp);
    off = strchr(tmp, '.');
    return (off ? strlen(off + 1) : 0);
}

/*
 * Find longest number of digits after the decimal point.
 */
static inline unsigned
maxPrecision(
    double start,
    double end,
    double step)
{
    unsigned dp = Precision(step);
    unsigned i = Precision(start);

    dp = i>dp ? i : dp;
    i  = Precision(end);
    dp = i>dp ? i : dp;
    return dp;
}



/*
 *----------------------------------------------------------------------
 *
 * ArithSeriesLen --
 *
 * 	Compute the length of the equivalent list where
 * 	every element is generated starting from *start*,

 * Side effects:
 *
 * 	None.
 *
 *----------------------------------------------------------------------
 */
static Tcl_WideInt
ArithSeriesLenInt(
    Tcl_WideInt start,
    Tcl_WideInt end,
    Tcl_WideInt step)
{
    Tcl_WideInt len;

    if (step == 0) {
	return 0;
    }
    len = 1 + ((end - start) / step);
    return (len < 0) ? -1 : len;
}

static Tcl_WideInt
ArithSeriesLenDbl(
    double start,
    double end,
    double step,
    unsigned precision)
{
    double istart, iend, istep, ilen;

    if (step == 0) {
	return 0;
    }
    istart = start * power10(precision);
    iend = end * power10(precision);
    istep = step * power10(precision);
    ilen = (iend - istart + istep) / istep;
    return floor(ilen);
}


/*
 *----------------------------------------------------------------------
 *
 * DupArithSeriesInternalRep --
 *
 *	Initialize the internal representation of a arithseries Tcl_Obj to a
 *	copy of the internal representation of an existing arithseries object.
 *	The copy does not share the cache of the elements.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	We set "copyPtr"s internal rep to a pointer to a
 *	newly allocated ArithSeries structure.
 *
 *----------------------------------------------------------------------
 */

static void
DupArithSeriesInternalRep(
    Tcl_Obj *srcPtr,		/* Object with internal rep to copy. */
    Tcl_Obj *copyPtr)		/* Object with internal rep to set. */
{
    ArithSeries *srcRepPtr = (ArithSeries *)
	    srcPtr->internalRep.twoPtrValue.ptr1;




    if (srcRepPtr->isDouble) {
	ArithSeriesDbl *srcDblPtr = (ArithSeriesDbl *) srcRepPtr;

	ArithSeriesDbl *copyDblPtr = (ArithSeriesDbl *)
		Tcl_Alloc(sizeof(ArithSeriesDbl));

	*copyDblPtr = *srcDblPtr;
	copyDblPtr->base.elements = NULL;
	copyPtr->internalRep.twoPtrValue.ptr1 = copyDblPtr;
    } else {
	ArithSeriesInt *srcIntPtr = (ArithSeriesInt *) srcRepPtr;
	ArithSeriesInt *copyIntPtr = (ArithSeriesInt *)
		Tcl_Alloc(sizeof(ArithSeriesInt));

	*copyIntPtr = *srcIntPtr;
	copyIntPtr->base.elements = NULL;
	copyPtr->internalRep.twoPtrValue.ptr1 = copyIntPtr;
    }
    copyPtr->internalRep.twoPtrValue.ptr2 = NULL;
    copyPtr->typePtr = &arithSeriesType;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeArithSeriesInternalRep --
 *
 *	Free any allocated memory in the ArithSeries Rep
 *
 * Results:
 *	None.
 *
 * Side effects:
 *
 *----------------------------------------------------------------------
 */



static inline void
FreeElements(
    ArithSeries *arithSeriesRepPtr)
{

    if (arithSeriesRepPtr->elements) {
	Tcl_WideInt i, len = arithSeriesRepPtr->len;

	for (i=0; i<len; i++) {
	    Tcl_DecrRefCount(arithSeriesRepPtr->elements[i]);
	}
	Tcl_Free((char *) arithSeriesRepPtr->elements);
	arithSeriesRepPtr->elements = NULL;
    }
}

static void
FreeArithSeriesInternalRep(
    Tcl_Obj *arithSeriesObjPtr)
{
    ArithSeries *arithSeriesRepPtr = (ArithSeries *)
	    arithSeriesObjPtr->internalRep.twoPtrValue.ptr1;

    if (arithSeriesRepPtr) {
	FreeElements(arithSeriesRepPtr);
	Tcl_Free((char *) arithSeriesRepPtr);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * NewArithSeriesInt --
 *
 *	Creates a new ArithSeries object. The returned object has
 *	refcount = 0.
 *
 * Results:
 *
 * 	A Tcl_Obj pointer to the created ArithSeries object.
 * 	A NULL pointer of the range is invalid.
 *
 * Side Effects:

 * 	None.
 *
 *----------------------------------------------------------------------
 */
static Tcl_Obj *
NewArithSeriesInt(
    Tcl_WideInt start,
    Tcl_WideInt end,
    Tcl_WideInt step,
    Tcl_WideInt len)
{
    Tcl_WideInt length;
    Tcl_Obj *arithSeriesObj;
    ArithSeriesInt *arithSeriesRepPtr;

    length = len>=0 ? len : -1;
    if (length < 0) {
	length = -1;
    }

    TclNewObj(arithSeriesObj);

    if (length <= 0) {
	return arithSeriesObj;
    }

    arithSeriesRepPtr = (ArithSeriesInt *) Tcl_Alloc(sizeof(ArithSeriesInt));
    arithSeriesRepPtr->base.len = length;
    arithSeriesRepPtr->base.elements = NULL;
    arithSeriesRepPtr->base.isDouble = 0;
    arithSeriesRepPtr->start = start;
    arithSeriesRepPtr->end = end;
    arithSeriesRepPtr->step = step;


    arithSeriesObj->internalRep.twoPtrValue.ptr1 = arithSeriesRepPtr;
    arithSeriesObj->internalRep.twoPtrValue.ptr2 = NULL;
    arithSeriesObj->typePtr = &arithSeriesType;
    if (length > 0) {
    	Tcl_InvalidateStringRep(arithSeriesObj);
    }

 *
 * Side Effects:
 *
 * 	None.
 *----------------------------------------------------------------------
 */

static Tcl_Obj *

NewArithSeriesDbl(
    double start,
    double end,
    double step,
    Tcl_WideInt len)
{
    Tcl_WideInt length;
    Tcl_Obj *arithSeriesObj;
    ArithSeriesDbl *arithSeriesRepPtr;

    length = len>=0 ? len : -1;
    if (length < 0) {
	length = -1;
    }

    TclNewObj(arithSeriesObj);

    if (length <= 0) {
	return arithSeriesObj;
    }

    arithSeriesRepPtr = (ArithSeriesDbl *) Tcl_Alloc(sizeof(ArithSeriesDbl));
    arithSeriesRepPtr->base.len = length;
    arithSeriesRepPtr->base.elements = NULL;
    arithSeriesRepPtr->base.isDouble = 1;
    arithSeriesRepPtr->start = start;
    arithSeriesRepPtr->end = end;
    arithSeriesRepPtr->step = step;


    arithSeriesRepPtr->precision = maxPrecision(start, end, step);
    arithSeriesObj->internalRep.twoPtrValue.ptr1 = arithSeriesRepPtr;
    arithSeriesObj->internalRep.twoPtrValue.ptr2 = NULL;
    arithSeriesObj->typePtr = &arithSeriesType;

    if (length > 0) {
    	Tcl_InvalidateStringRep(arithSeriesObj);
    }

		step = (start < end) ? 1 : -1;
		dstep = step;
	    }
	}
	assert(dstep!=0);
	if (!lenObj) {
	    if (useDoubles) {
		unsigned precision = maxPrecision(dstart, dend, dstep);
		len = ArithSeriesLenDbl(dstart, dend, dstep, precision);
	    } else {
		len = ArithSeriesLenInt(start, end, step);
	    }
	}
    }

    if (!endObj) {
	if (useDoubles) {
	    // Compute precision based on given command argument values
	    unsigned precision = maxPrecision(dstart, len, dstep);

	    dend = dstart + (dstep * (len-1));
	    // Make computed end value match argument(s) precision
	    dend = ArithRound(dend, precision);
	    end = dend;
	} else {
	    end = start + (step * (len - 1));
	    dend = end;
	}
    }

    if (len > TCL_SIZE_MAX) {
	Tcl_SetObjResult(interp, Tcl_NewStringObj(

		"max length of a Tcl list exceeded", TCL_AUTO_LENGTH));
	Tcl_SetErrorCode(interp, "TCL", "MEMORY", (void *)NULL);
	return TCL_ERROR;
    }

    if (arithSeriesObj) {
	*arithSeriesObj = (useDoubles)
	    ? NewArithSeriesDbl(dstart, dend, dstep, len)

 * Side Effects:
 *
 * 	On success, the integer pointed by *element is modified.
 * 	An empty string ("") is assigned if index is out-of-bounds.
 *
 *----------------------------------------------------------------------
 */

int
TclArithSeriesObjIndex(
    TCL_UNUSED(Tcl_Interp *),
    Tcl_Obj *arithSeriesObj,	/* List obj */
    Tcl_Size index,		/* index to element of interest */
    Tcl_Obj **elemObj)		/* Return value */
{
    ArithSeries *arithSeriesRepPtr = ArithSeriesGetInternalRep(arithSeriesObj);

    if (index < 0 || arithSeriesRepPtr->len <= index) {
	*elemObj = NULL;
    } else {
	/* List[i] = Start + (Step * index) */

 *
 *----------------------------------------------------------------------
 */
Tcl_Size
ArithSeriesObjLength(
    Tcl_Obj *arithSeriesObj)
{
    ArithSeries *arithSeriesRepPtr = (ArithSeries *)
	    arithSeriesObj->internalRep.twoPtrValue.ptr1;
    return arithSeriesRepPtr->len;
}

/*
 *----------------------------------------------------------------------
 *

int
TclArithSeriesObjStep(
    Tcl_Obj *arithSeriesObj,
    Tcl_Obj **stepObj)
{
    ArithSeries *arithSeriesRepPtr = ArithSeriesGetInternalRep(arithSeriesObj);

    if (arithSeriesRepPtr->isDouble) {
	*stepObj = Tcl_NewDoubleObj(((ArithSeriesDbl *) arithSeriesRepPtr)->step);
    } else {
	*stepObj = Tcl_NewWideIntObj(((ArithSeriesInt *) arithSeriesRepPtr)->step);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * SetArithSeriesFromAny --
 *
 * 	The Arithmetic Series object is just an way to optimize
 * 	Lists space complexity, so no one should try to convert

    if (fromIdx < 0) {
	fromIdx = 0;
    }
    if (toIdx < 0) {
	toIdx = 0;
    }
    if (toIdx > arithSeriesRepPtr->len - 1) {
	toIdx = arithSeriesRepPtr->len - 1;
    }

    TclArithSeriesObjIndex(interp, arithSeriesObj, fromIdx, &startObj);
    Tcl_IncrRefCount(startObj);
    TclArithSeriesObjIndex(interp, arithSeriesObj, toIdx, &endObj);
    Tcl_IncrRefCount(endObj);
    TclArithSeriesObjStep(arithSeriesObj, &stepObj);

     * Even if nothing below causes any changes, we still want the
     * string-canonizing effect of [lrange 0 end].
     */

    TclInvalidateStringRep(arithSeriesObj);

    if (arithSeriesRepPtr->isDouble) {
	ArithSeriesDbl *dblRepPtr = (ArithSeriesDbl *) arithSeriesRepPtr;
	double start, end, step;

	Tcl_GetDoubleFromObj(NULL, startObj, &start);
	Tcl_GetDoubleFromObj(NULL, endObj, &end);
	Tcl_GetDoubleFromObj(NULL, stepObj, &step);
	dblRepPtr->start = start;
	dblRepPtr->end = end;
	dblRepPtr->step = step;
	dblRepPtr->precision = maxPrecision(start, end, step);
	FreeElements(arithSeriesRepPtr);
	dblRepPtr->base.len =
		ArithSeriesLenDbl(start, end, step, dblRepPtr->precision);


    } else {
	ArithSeriesInt *intRepPtr = (ArithSeriesInt *) arithSeriesRepPtr;
	Tcl_WideInt start, end, step;

	Tcl_GetWideIntFromObj(NULL, startObj, &start);
	Tcl_GetWideIntFromObj(NULL, endObj, &end);
	Tcl_GetWideIntFromObj(NULL, stepObj, &step);
	intRepPtr->start = start;
	intRepPtr->end = end;
	intRepPtr->step = step;
	FreeElements(arithSeriesRepPtr);
	intRepPtr->base.len = ArithSeriesLenInt(start, end, step);

    }

    Tcl_DecrRefCount(startObj);
    Tcl_DecrRefCount(endObj);
    Tcl_DecrRefCount(stepObj);

    *newObjPtr = arithSeriesObj;

				 * array is to be returned. */
    Tcl_Size *objcPtr,		/* Where to store the count of objects
				 * referenced by objv. */
    Tcl_Obj ***objvPtr)		/* Where to store the pointer to an array of
				 * pointers to the list's objects. */
{
    if (TclHasInternalRep(objPtr, &arithSeriesType)) {
	ArithSeries *arithSeriesRepPtr = ArithSeriesGetInternalRep(objPtr);
	Tcl_Obj **objv;


	Tcl_Size objc = arithSeriesRepPtr->len;


	if (objc > 0) {
	    if (arithSeriesRepPtr->elements) {
		/* If this exists, it has already been populated */
		objv = arithSeriesRepPtr->elements;
	    } else {
		/* Construct the elements array */
		objv = (Tcl_Obj **) Tcl_Alloc(sizeof(Tcl_Obj*) * objc);
		if (objv == NULL) {
		    if (interp) {
			Tcl_SetObjResult(interp, Tcl_NewStringObj(

				"max length of a Tcl list exceeded",
				TCL_AUTO_LENGTH));
			Tcl_SetErrorCode(interp, "TCL", "MEMORY", (void *)NULL);
		    }
		    return TCL_ERROR;
		}
		arithSeriesRepPtr->elements = objv;

		Tcl_Size i;
		for (i = 0; i < objc; i++) {
		    int status = TclArithSeriesObjIndex(interp, objPtr, i, &objv[i]);

		    if (status) {
			return TCL_ERROR;
		    }
		    Tcl_IncrRefCount(objv[i]);
		}
	    }
	} else {
	    objv = NULL;
	}
	*objvPtr = objv;
	*objcPtr = objc;
    } else {
	if (interp != NULL) {
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(
		    "value is not an arithseries", TCL_AUTO_LENGTH));
	    Tcl_SetErrorCode(interp, "TCL", "VALUE", "UNKNOWN", (void *)NULL);
	}
	return TCL_ERROR;
    }
    return TCL_OK;
}


    }

    arithSeriesRepPtr = ArithSeriesGetInternalRep(arithSeriesObj);

    isDouble = arithSeriesRepPtr->isDouble;
    len = arithSeriesRepPtr->len;

    TclArithSeriesObjIndex(NULL, arithSeriesObj, len - 1, &startObj);
    Tcl_IncrRefCount(startObj);
    TclArithSeriesObjIndex(NULL, arithSeriesObj, 0, &endObj);
    Tcl_IncrRefCount(endObj);
    TclArithSeriesObjStep(arithSeriesObj, &stepObj);
    Tcl_IncrRefCount(stepObj);

    if (isDouble) {

	Tcl_GetWideIntFromObj(NULL, stepObj, &step);
	step = -step;
	TclSetIntObj(stepObj, step);
    }

    if (Tcl_IsShared(arithSeriesObj) || (arithSeriesObj->refCount > 1)) {
	Tcl_Obj *lenObj;

	TclNewIntObj(lenObj, len);
	if (TclNewArithSeriesObj(NULL, &resultObj, isDouble,
		startObj, endObj, stepObj, lenObj) != TCL_OK) {
	    resultObj = NULL;
	}
	Tcl_DecrRefCount(lenObj);
    } else {

	/*
	 * In-place is possible.
	 */

	TclInvalidateStringRep(arithSeriesObj);

	if (isDouble) {
	    ArithSeriesDbl *dblRepPtr = (ArithSeriesDbl *) arithSeriesRepPtr;

	    dblRepPtr->start = dstart;
	    dblRepPtr->end = dend;
	    dblRepPtr->step = dstep;
	} else {
	    ArithSeriesInt *intRepPtr = (ArithSeriesInt *) arithSeriesRepPtr;
	    intRepPtr->start = start;
	    intRepPtr->end = end;
	    intRepPtr->step = step;
	}
	FreeElements(arithSeriesRepPtr);








	resultObj = arithSeriesObj;
    }

    Tcl_DecrRefCount(startObj);
    Tcl_DecrRefCount(endObj);
    Tcl_DecrRefCount(stepObj);

 * 	the length of the string representation and make this procedure
 * 	much faster. Because the programmer shouldn't expect the
 * 	string conversion of a big arithmetic sequence to be fast
 * 	this version takes more care of space than time.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateStringOfArithSeries(
    Tcl_Obj *arithSeriesObjPtr)
{
    ArithSeries *arithSeriesRepPtr = (ArithSeries *)
	    arithSeriesObjPtr->internalRep.twoPtrValue.ptr1;
    char *p;
    Tcl_Obj *eleObj;
    Tcl_Size i, bytlen = 0;

    /*
     * Pass 1: estimate space.
     */
    if (!arithSeriesRepPtr->isDouble) {
	for (i = 0; i < arithSeriesRepPtr->len; i++) {
	    double d = ArithSeriesIndexInt(arithSeriesRepPtr, i);
	    size_t slen = d>0 ? log10(d)+1 : d<0 ? log10(-d)+2 : 1;

	    bytlen += slen;
	}
    } else {
	for (i = 0; i < arithSeriesRepPtr->len; i++) {
	    double d = ArithSeriesIndexDbl(arithSeriesRepPtr, i);
	    char tmp[TCL_DOUBLE_SPACE + 2];

	    tmp[0] = 0;
	    Tcl_PrintDouble(NULL,d,tmp);
	    if ((bytlen + strlen(tmp)) > TCL_SIZE_MAX) {
		break; // overflow
	    }
	    bytlen += strlen(tmp);
	}
    }
    bytlen += arithSeriesRepPtr->len; // Space for each separator

    /*
     * Pass 2: generate the string repr.
     */

    p = Tcl_InitStringRep(arithSeriesObjPtr, NULL, bytlen);
    for (i = 0; i < arithSeriesRepPtr->len; i++) {
	if (TclArithSeriesObjIndex(NULL, arithSeriesObjPtr, i, &eleObj) == TCL_OK) {
	    Tcl_Size slen;
	    char *str = TclGetStringFromObj(eleObj, &slen);

	    strcpy(p, str);
	    p[slen] = ' ';
	    p += slen + 1;
	    Tcl_DecrRefCount(eleObj);
	} // else TODO: report error here?
    }
    if (bytlen > 0) {

static int
ArithSeriesInOperation(
    Tcl_Interp *interp,
    Tcl_Obj *valueObj,
    Tcl_Obj *arithSeriesObjPtr,
    int *boolResult)
{
    ArithSeries *repPtr = (ArithSeries *)
	    arithSeriesObjPtr->internalRep.twoPtrValue.ptr1;

    int status;
    Tcl_Size index, incr, elen, vlen;

    if (repPtr->isDouble) {
	ArithSeriesDbl *dblRepPtr = (ArithSeriesDbl *) repPtr;
	double y;
	int test = 0;

	incr = 0; // Check index+incr where incr is 0 and 1
	status = Tcl_GetDoubleFromObj(interp, valueObj, &y);
	if (status != TCL_OK) {
	    test = 0;
	} else {
	    const char *vstr = TclGetStringFromObj(valueObj, &vlen);
	    index = (y - dblRepPtr->start) / dblRepPtr->step;
	    while (incr<2) {
		Tcl_Obj *elemObj;

		elen = 0;
		TclArithSeriesObjIndex(interp, arithSeriesObjPtr, (index+incr), &elemObj);

		const char *estr = elemObj ? TclGetStringFromObj(elemObj, &elen) : "";

		/* "in" operation defined as a string compare */
		test = (elen == vlen) ? (memcmp(estr, vstr, elen) == 0) : 0;
		Tcl_BounceRefCount(elemObj);
		/* Stop if we have a match */
		if (test) {
		    break;
		}
		incr++;
	    }
	}
	if (boolResult) {
	    *boolResult = test;
	}
    } else {
	ArithSeriesInt *intRepPtr = (ArithSeriesInt *) repPtr;
	Tcl_WideInt y;

	status = Tcl_GetWideIntFromObj(NULL, valueObj, &y);
	if (status != TCL_OK) {
	    if (boolResult) {
		*boolResult = 0;
	    }
	} else {
	    Tcl_Obj *elemObj;

	    elen = 0;
	    index = (y - intRepPtr->start) / intRepPtr->step;
	    TclArithSeriesObjIndex(interp, arithSeriesObjPtr, index, &elemObj);

	    char const *vstr = TclGetStringFromObj(valueObj, &vlen);
	    char const *estr = elemObj ? TclGetStringFromObj(elemObj, &elen) : "";

	    if (boolResult) {
		*boolResult = (elen == vlen) ? (memcmp(estr, vstr, elen) == 0) : 0;
	    }
	    Tcl_BounceRefCount(elemObj);
	}
    }
    return TCL_OK;