Like parenthesize, I'm copying tests over from https://github.com/akkartik/wart
Unlike parenthesize, though, I can't just transliterate the code itself.
Wart was operating on an intermediate AST representation. Here I'm all
the way down to cells. That seemed like a good idea when I embarked, but
now I'm not so sure. Operating with the right AST data structure allowed
me to more easily iterate over the elements of a list. The natural recursion
for cells is not a good fit.
This patch and the next couple is an interesting case study in what makes
Unix so effective. Yes, you have to play computer, and yes it gets verbose
and ugly. But just diff and patch go surprisingly far in helping build a
picture of the state space in my brain.
Then again, there's a steep gradient of skills here. There are people who
can visualize state spaces using diff and patch far better than me, and
people who can't do it as well as me. Nature, nurture, having different
priorities, whatever the reason. Giving some people just the right crutch
excludes others.
I wrote a comment about how some code was not covered by tests, and then
promptly forgot what it was for. This is why we need tests.
Now the hack is gone.
This was quite difficult to diagnose. The issue I noticed was that brline
had stopped working. All the bugs in previous commits were hiding the cause.
Once I cleaned them up, I realized the problem was that the `(,x0 ,y0)
was triggering the nested-backquote check. The fix was fairly straightforward
then (even though I didn't yet understand why). But how to write a test
for this? I spent some time trying to do so without defining a macro using
literal macros, before I realized:
You can't call literal macros; we don't have first-class macros.
Trying to insert literal macro support just breaks everything because we
have no way to distinguish between a literal macro call and the stage in
macroexpand where a symbol has been replaced with its macro definition.
How do you explain stuff like this? I grow weary of Lisp.
There's still some issue in loading the entire definition of brline from
data.limg.
We now use traces everywhere for error-checking. Null traces introduce
the possibility of changing a functions error response, and therefore its
semantics.
In the process I spent a long time tracking down a stray TODO in 108write.subx
that I thought would abort but didn't since the switch to baremetal.
Then after I reintroduced that assertion I had to go track down a bunch
of buffer sizes. Stream sizes continue to be a huge mess.
Kartik K. Agaram