Re: set-text-properties, remove-set-properties, add-text-properties: 1) doc string 2) return value

[Kevin Rodgers]

Drew Adams wrote:
>     >> 2. Wouldn't it be more useful for set-text-properties,
>     >> remove-set-properties, and add-text-properties to return the modified
>     >> OBJECT (or nil if no modification occurred)? In case OBJECT
>     >> is a buffer (or nil), the modified buffer substring could be
> returned.
>     >
>     > Why would that be useful?
>
>     Even if it was useful in some cases, it would be extremely
>     wasteful in general.
>
> I believe you, but could you explain why, so I can learn? I don't know much
> about how C interfaces with Lisp. Is it because a new OBJECT would in fact
> need to be created? I was thinking that the operation could just return (the
> equivalent of) a pointer to the original OBJECT. IOW, where is the waste?
>
> I guess, in the case of a buffer, a new string would need to be created. Is
> that what you meant, or is there also a problem when the OBJECT (string)
> argument is explicitly supplied?

Exactly.  I think it should just return OBJECT, whether that is a buffer
(or the current buffer, when nil) or a string.

--
Kevin Rodgers