Re: Touchup of history.c

[Daniel J S. <dan...@ie...>]

Petr Mikulik wrote:
>>>>Several of these options may be overridden by similar qualifiers in the
>>>>history command.
>>>>     set history {<int>}
>>>
>>>I tried that "set history -1" makes an error.
>>
>>gnuplot> set history -1
>>                     ^
>>         Unrecognized option.
>>
>>Are you getting something else? 
> 
> 
> I get the same.
> 
> 
>  Of course, that means the following also
> 
> 
>>Should we be recognizing the sign and then issuing an error if negative?
> 
> 
> Yes.

I began programming this, but now I hesitate to do so.  It would be something like

n = 1;
if (equals(c_token,"-")) {
     n *= -1;
     c_token++;
} else if (equals(c_token,"+"))
     c_token++;
n *= int_expression();

But to repeat this code in more than one spot wouldn't be good.  There should 
maybe be "signed_expression()" inside parse.h.

However, on second thought, just leaving it as is makes the user be a little 
cleaner in their use of integers.  I don't think it is good practice for users 
to be doing

set history +3

etc.  That simply clutters things.  I suggest leaving it as is with the 
"Unrecognized option" error.

Dan