/*
* charrecv - converts external binary format to char
*
* The external representation is one byte, with no character set
* conversion. This is somewhat dubious, perhaps, but in many
* cases people use char for a 1-byte binary type.
*/
Datum
charrecv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
PG_RETURN_CHAR(pq_getmsgbyte(buf));
}
/*
* charin - converts "x" to 'x'
*
* Note that an empty input string will implicitly be converted to \0.
*/
Datum
charin(PG_FUNCTION_ARGS)
{
char *ch = PG_GETARG_CSTRING(0);
PG_RETURN_CHAR(ch[0]);
}
Datum
charmul(PG_FUNCTION_ARGS)
{
char arg1 = PG_GETARG_CHAR(0);
char arg2 = PG_GETARG_CHAR(1);
PG_RETURN_CHAR((int8) arg1 * (int8) arg2);
}
Datum
i4tochar(PG_FUNCTION_ARGS)
{
int32 arg1 = PG_GETARG_INT32(0);
if (arg1 < SCHAR_MIN || arg1 > SCHAR_MAX)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("\"char\" out of range")));
PG_RETURN_CHAR((int8) arg1);
}
Datum
chardiv(PG_FUNCTION_ARGS)
{
char arg1 = PG_GETARG_CHAR(0);
char arg2 = PG_GETARG_CHAR(1);
if (arg2 == 0)
ereport(ERROR,
(errcode(ERRCODE_DIVISION_BY_ZERO),
errmsg("division by zero")));
PG_RETURN_CHAR((int8) arg1 / (int8) arg2);
}
Datum
text_char(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
char result;
/*
* An empty input string is converted to \0 (for consistency with charin).
* If the input is longer than one character, the excess data is silently
* discarded.
*/
if (VARSIZE(arg1) > VARHDRSZ)
result = *(VARDATA(arg1));
else
result = '\0';
PG_RETURN_CHAR(result);
}
