Re: [tarantool-patches] Re: [PATCH] decimal: add methods truncate and set_scale

[Serge Petrenko <sergepetrenko@tarantool.org>]

> 19 июля 2019 г., в 14:57, Konstantin Osipov <kostja@tarantool.org> написал(а):
> 
> * Serge Petrenko <sergepetrenko@tarantool.org> [19/07/19 14:42]:
>> This patch adds 2 methods to decimal library and lua module:
>> truncate will remove all trailing fractional zeros and set_scale will
>> either perform rounding or append excess fractional zeros.
>> 
> 
> Please note that it is Trim in the ldec library.
> truncate() has a slightly different meaning.
> 
>> +decimal_t *
>> +decimal_truncate(decimal_t *dec)
>> +{
>> +	decimal_t *res = decNumberTrim(dec);
>> +
>> +	/* No errors are possible */
>> +	assert(res == dec);
>> +	return res;
>> +}
>> +
>> +decimal_t *
>> +decimal_set_scale(decimal_t *dec, int scale)
>> +{
>> +	if (scale < 0)
>> +		return NULL;
>> +	if (scale <= decimal_scale(dec))
>> +		return decimal_round(dec, scale);
>> +	/* how much zeros shoud we append. */
>> +	int delta = scale + dec->exponent;
>> +	if (scale > DECIMAL_MAX_DIGITS || dec->digits + delta > DECIMAL_MAX_DIGITS)
>> +		return NULL;
>> +	decimal_t new_scale;
>> +	decimal_from_int64(&new_scale, -scale);
>> +	decNumberRescale(dec, dec, &new_scale, &decimal_context);
>> +	assert(decimal_check_status(dec, &decimal_context) != NULL);
>> +	return dec;
> 
> Please also note here: the name is rescale(), not set_scale(). The
> meaning of set_scale() is slightly different.
> 
> Please use less confusing names.

Hi! Thank you for review.
No problem, renamed to trim() and rescale().
The changes are on the branch.

> 
> otherwise lgtm.
> 
> -- 
> Konstantin Osipov, Moscow, Russia
> 


--
Serge Petrenko
sergepetrenko@tarantool.org