From: Robert Pluim <rpluim@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 59531@debbugs.gnu.org,
Ramesh Nedunchezian <rameshnedunchezian@outlook.com>
Subject: bug#59531: 29.0.50: An alternative to `string-to-number` which throws an error (or returns a NIL value) when input is non-parseable as number
Date: Wed, 14 Dec 2022 17:40:24 +0100 [thread overview]
Message-ID: <87zgbqndl3.fsf@gmail.com> (raw)
In-Reply-To: <838rk0ye7t.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 24 Nov 2022 10:00:06 +0200")
>>>>> On Thu, 24 Nov 2022 10:00:06 +0200, Eli Zaretskii <eliz@gnu.org> said:
>> This return value is not very helpful. The choice of a number ZERO
>> as "Not A Number" doesn't help one to distinguish between the
>> following two cases
>>
>> (1) Input was a valid number, and it parses to number zero
>>
>> (2) Input was NOT a valid number, and it was forcibly reported as ZERO
>>
>> Consider amending `string-to-number` to throw an error (or return
>> NIL) when the input is not parseable as a number, or providing an
>> alternative API to validate numbers. I am trying to parse some
>> fields in an org table, and see if the field value is a number or
>> not;
Eli> Thanks.
Eli> Changing the default behavior to signal an error is out of the question,
Eli> since this is used in the Lisp reader and elsewhere, all over the place. It
Eli> is very useful there.
Eli> However, as an enhancement, we could have an additional optional argument to
Eli> request that the function signal an error if the string cannot be parsed as
Eli> a number.
`cl-parse-integer' already has such an argument, but it only works for
integers. Alternatively, you could use `read-from-string' and check if
it returns something of type `integer' or `float'.
Robert
--
next prev parent reply other threads:[~2022-12-14 16:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-24 6:14 bug#59531: 29.0.50: An alternative to `string-to-number` which throws an error (or returns a NIL value) when input is non-parseable as number Ramesh Nedunchezian
2022-11-24 8:00 ` Eli Zaretskii
2022-12-14 16:40 ` Robert Pluim [this message]
2022-12-16 6:28 ` Jean Louis
2022-11-24 10:08 ` Jean Louis
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