cash.c

PostgreSQL7.4.6 for Linux

	if (c1 > c2)
		PG_RETURN_INT32(1);
	else if (c1 == c2)
		PG_RETURN_INT32(0);
	else
		PG_RETURN_INT32(-1);
}


/* cash_pl()
 * Add two cash values.
 */
Datum
cash_pl(PG_FUNCTION_ARGS)
{
	Cash		c1 = PG_GETARG_CASH(0);
	Cash		c2 = PG_GETARG_CASH(1);
	Cash		result;

	result = c1 + c2;

	PG_RETURN_CASH(result);
}


/* cash_mi()
 * Subtract two cash values.
 */
Datum
cash_mi(PG_FUNCTION_ARGS)
{
	Cash		c1 = PG_GETARG_CASH(0);
	Cash		c2 = PG_GETARG_CASH(1);
	Cash		result;

	result = c1 - c2;

	PG_RETURN_CASH(result);
}


/* cash_mul_flt8()
 * Multiply cash by float8.
 */
Datum
cash_mul_flt8(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	float8		f = PG_GETARG_FLOAT8(1);
	Cash		result;

	result = c * f;
	PG_RETURN_CASH(result);
}


/* flt8_mul_cash()
 * Multiply float8 by cash.
 */
Datum
flt8_mul_cash(PG_FUNCTION_ARGS)
{
	float8		f = PG_GETARG_FLOAT8(0);
	Cash		c = PG_GETARG_CASH(1);
	Cash		result;

	result = f * c;
	PG_RETURN_CASH(result);
}


/* cash_div_flt8()
 * Divide cash by float8.
 *
 * XXX Don't know if rounding or truncating is correct behavior.
 * Round for now. - tgl 97/04/15
 */
Datum
cash_div_flt8(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	float8		f = PG_GETARG_FLOAT8(1);
	Cash		result;

	if (f == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = rint(c / f);
	PG_RETURN_CASH(result);
}

/* cash_mul_flt4()
 * Multiply cash by float4.
 */
Datum
cash_mul_flt4(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	float4		f = PG_GETARG_FLOAT4(1);
	Cash		result;

	result = c * f;
	PG_RETURN_CASH(result);
}


/* flt4_mul_cash()
 * Multiply float4 by cash.
 */
Datum
flt4_mul_cash(PG_FUNCTION_ARGS)
{
	float4		f = PG_GETARG_FLOAT4(0);
	Cash		c = PG_GETARG_CASH(1);
	Cash		result;

	result = f * c;
	PG_RETURN_CASH(result);
}


/* cash_div_flt4()
 * Divide cash by float4.
 *
 * XXX Don't know if rounding or truncating is correct behavior.
 * Round for now. - tgl 97/04/15
 */
Datum
cash_div_flt4(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	float4		f = PG_GETARG_FLOAT4(1);
	Cash		result;

	if (f == 0.0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = rint(c / f);
	PG_RETURN_CASH(result);
}


/* cash_mul_int4()
 * Multiply cash by int4.
 */
Datum
cash_mul_int4(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	int32		i = PG_GETARG_INT32(1);
	Cash		result;

	result = c * i;
	PG_RETURN_CASH(result);
}


/* int4_mul_cash()
 * Multiply int4 by cash.
 */
Datum
int4_mul_cash(PG_FUNCTION_ARGS)
{
	int32		i = PG_GETARG_INT32(0);
	Cash		c = PG_GETARG_CASH(1);
	Cash		result;

	result = i * c;
	PG_RETURN_CASH(result);
}


/* cash_div_int4()
 * Divide cash by 4-byte integer.
 *
 * XXX Don't know if rounding or truncating is correct behavior.
 * Round for now. - tgl 97/04/15
 */
Datum
cash_div_int4(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	int32		i = PG_GETARG_INT32(1);
	Cash		result;

	if (i == 0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = rint(c / i);

	PG_RETURN_CASH(result);
}


/* cash_mul_int2()
 * Multiply cash by int2.
 */
Datum
cash_mul_int2(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	int16		s = PG_GETARG_INT16(1);
	Cash		result;

	result = c * s;
	PG_RETURN_CASH(result);
}

/* int2_mul_cash()
 * Multiply int2 by cash.
 */
Datum
int2_mul_cash(PG_FUNCTION_ARGS)
{
	int16		s = PG_GETARG_INT16(0);
	Cash		c = PG_GETARG_CASH(1);
	Cash		result;

	result = s * c;
	PG_RETURN_CASH(result);
}

/* cash_div_int2()
 * Divide cash by int2.
 *
 * XXX Don't know if rounding or truncating is correct behavior.
 * Round for now. - tgl 97/04/15
 */
Datum
cash_div_int2(PG_FUNCTION_ARGS)
{
	Cash		c = PG_GETARG_CASH(0);
	int16		s = PG_GETARG_INT16(1);
	Cash		result;

	if (s == 0)
		ereport(ERROR,
				(errcode(ERRCODE_DIVISION_BY_ZERO),
				 errmsg("division by zero")));

	result = rint(c / s);
	PG_RETURN_CASH(result);
}

/* cashlarger()
 * Return larger of two cash values.
 */
Datum
cashlarger(PG_FUNCTION_ARGS)
{
	Cash		c1 = PG_GETARG_CASH(0);
	Cash		c2 = PG_GETARG_CASH(1);
	Cash		result;

	result = (c1 > c2) ? c1 : c2;

	PG_RETURN_CASH(result);
}

/* cashsmaller()
 * Return smaller of two cash values.
 */
Datum
cashsmaller(PG_FUNCTION_ARGS)
{
	Cash		c1 = PG_GETARG_CASH(0);
	Cash		c2 = PG_GETARG_CASH(1);
	Cash		result;

	result = (c1 < c2) ? c1 : c2;

	PG_RETURN_CASH(result);
}


/* cash_words()
 * This converts a int4 as well but to a representation using words
 * Obviously way North American centric - sorry
 */
Datum
cash_words(PG_FUNCTION_ARGS)
{
	Cash		value = PG_GETARG_CASH(0);
	unsigned int val;
	char		buf[256];
	char	   *p = buf;
	Cash		m0;
	Cash		m1;
	Cash		m2;
	Cash		m3;
	text	   *result;

	/* work with positive numbers */
	if (value < 0)
	{
		value = -value;
		strcpy(buf, "minus ");
		p += 6;
	}
	else
		buf[0] = '\0';

	/* Now treat as unsigned, to avoid trouble at INT_MIN */
	val = (unsigned int) value;

	m0 = val % 100;				/* cents */
	m1 = (val / 100) % 1000;	/* hundreds */
	m2 = (val / 100000) % 1000; /* thousands */
	m3 = val / 100000000 % 1000;	/* millions */

	if (m3)
	{
		strcat(buf, num_word(m3));
		strcat(buf, " million ");
	}

	if (m2)
	{
		strcat(buf, num_word(m2));
		strcat(buf, " thousand ");
	}

	if (m1)
		strcat(buf, num_word(m1));

	if (!*p)
		strcat(buf, "zero");

	strcat(buf, (val / 100) == 1 ? " dollar and " : " dollars and ");
	strcat(buf, num_word(m0));
	strcat(buf, m0 == 1 ? " cent" : " cents");

	/* capitalize output */
	buf[0] = toupper((unsigned char) buf[0]);

	/* make a text type for output */
	result = (text *) palloc(strlen(buf) + VARHDRSZ);
	VARATT_SIZEP(result) = strlen(buf) + VARHDRSZ;
	memcpy(VARDATA(result), buf, strlen(buf));

	PG_RETURN_TEXT_P(result);
}


/*************************************************************************
 * Private routines
 ************************************************************************/

static const char *
num_word(Cash value)
{
	static char buf[128];
	static const char *small[] = {
		"zero", "one", "two", "three", "four", "five", "six", "seven",
		"eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen",
		"fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty",
		"thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"
	};
	const char **big = small + 18;
	int			tu = value % 100;

	/* deal with the simple cases first */
	if (value <= 20)
		return small[value];

	/* is it an even multiple of 100? */
	if (!tu)
	{
		sprintf(buf, "%s hundred", small[value / 100]);
		return buf;
	}

	/* more than 99? */
	if (value > 99)
	{
		/* is it an even multiple of 10 other than 10? */
		if (value % 10 == 0 && tu > 10)
			sprintf(buf, "%s hundred %s",
					small[value / 100], big[tu / 10]);
		else if (tu < 20)
			sprintf(buf, "%s hundred and %s",
					small[value / 100], small[tu]);
		else
			sprintf(buf, "%s hundred %s %s",
					small[value / 100], big[tu / 10], small[tu % 10]);

	}
	else
	{
		/* is it an even multiple of 10 other than 10? */
		if (value % 10 == 0 && tu > 10)
			sprintf(buf, "%s", big[tu / 10]);
		else if (tu < 20)
			sprintf(buf, "%s", small[tu]);
		else
			sprintf(buf, "%s %s", big[tu / 10], small[tu % 10]);
	}

	return buf;
}	/* num_word() */