RE: window-body-height vs window-text-height

[Drew Adams]

>  > If there is a partial line at the bottom of the window,
>  > window-text-height rounds down, and window-body-height rounds up.
>  > If there are no fractional lines, both return the same value.
>  >
>  > [In both cases, the number of lines assumes the default 
>  > face -- neither measures what's actually displayed.]
> 
> Aha.  Thanks for this information.

Just wondering: Why not just one function, with an additional arg to indicate
the difference?