Re: [PATCH 1/9] ref-filter: implement %(if), %(then), and %(else) atoms

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 2, 2015, 20:45 UTC
Message-ID: <xmqqpp0x3spo.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <1443807546-5985-2-git-send-email-Karthik.188@gmail.com>

Karthik Nayak <karthik.188@gmail.com> writes:

Show 8 quoted lines

> +static int is_empty(const char * s){
> +	while (*s != '\0') {
> +		if (!isspace(*s))
> +			return 0;
> +		s++;
> +	}
> +	return 1;
> +}

My knee-jerk reaction was "why is space so special?", but if a caller really cared, it can do "%(if:not_equal=)%(something)%(then)" to unignore spaces in %(something), so it is not a huge deal. It may be that ignoring spaces when checking if something is empty is so common that this default is useful---I cannot tell offhand.

Show 6 quoted lines

> +if::
> +	Used as %(if)..%(then)..(%end) or %(if)..%(then)..%(else)..%(end).
> +	If there is an atom with value or string literal after the
> +	%(if) then everything after the %(then) is printed, else if
> +	the %(else) atom is used, then everything after %(else) is
> +	printed.

I notice that "we ignore space when evaluating the string before %(then)" is not mentioned here. That fact, and an example or two that illustrates the situation where this "ignore spaces" behaviour is useful, would be a good thing to document here.

Thanks.