Re: Issue 3330: redo much of the stencil stacking/spacing/empty-check (issue 8869044)

[dak]

On 2013/05/03 05:18:26, Keith wrote:
> Shucks.  It gets difficult to space a list of stencils if all you have
to work
> with are the refpoint and extents of the next stencil, and the
composite of
> those accumulated so far.

> What we would like is :
> \line {a b c ... } places the left extent of each markup in the list
against the
> right extent of the previous markup, plus padding specified by the
property
> 'word-space.  The result is a markup with extent that encloses the
extents of
> all the individual markups, and overall reference point at the
reference point
> of the first markup 'a'.

> We just need to keep track of one variable: the right extent of the
> most-recently placed markup.  Too bad Scheme doesn't provide a way to
keep a
> running variable as you walk the list.  I guess that is why procedural
languages
> are so much better than functional languages.

Uh what?  Named lets are pretty fine for doing that sort of thing.  I
don't keep additional state variables in order to make the behavior more
predictable and become less dependent on assembly order.

Come to think of it: stack-stencil-lines should be doable without
additional state variables by going backwards in the list.

https://codereview.appspot.com/8869044/