Two-Dimensional Expression Layout

[Michael Selik]

On Sat, Aug 20, 2016 at 6:21 PM Lawrence D’Oliveiro <lawrencedo99 at gmail.com>
wrote:

> >     p0 = (0, 0)
> >     p1 = (major_dim, 0)
> >     colour_stops = (0, rect_1_colour), (1, complement(rect_1_colour))
> >     rect_1_pattern = qah.Pattern.create_linear(p0, p1, colour_stops)
>
> That’s an example of what I mean about obscure structure.
>

To each his own. I was assuming all those variable names meant something to
you. If not, then I expect it'd read well with good names. In this example,
I think the abbreviations and numbers in the names could be changed to
something more meaningful.


> >> From <https://github.com/ldo/python_pixman/blob/master/pixman.py>, a
> >> complex condition (with redundant parentheses again):
> >>
> >>     if (
> >>             not isinstance(src, Image)
> >>         or
> >>             mask != None and not isinstance(mask, Image)
> >>         or
> >>             not isinstance(dest, Image)
> >>     ) :
> >>         raise TypeError("image args must be Image objects")
> >>     #end if
> >>
> >
> > No need for the separate calls to isinstance, nor the check for None.
> >
> >     if any(not isinstance(obj, Image) for obj in [src, mask, dest]):
> >         ...
>
> Spot the bug in your version...
>

It'd be easier if I ran the code :-)
Let's see...
- the ``or`` translates to an ``any(...)``
- ``not isinstance(obj, Image)`` is repeated 3 times
- ``[src, mask, dest]`` corresponds to the 3 objects
- ``mask != None`` is unnecessary, unless somehow None has been registered
as an instance of Image.

... can't spot it. Give me a hint?