errors and treats them as failing to satisfy the property
This bug disables the occurs check and, thanks to the now
tighter contracts on the uh function, this can cause it to
signal an error. Here's the example:
(term (unify (x → (list int)) ((list x) → x)))
found by in-order enumeration (so naturally it had ||
variables in it, not 'x's originally)
This leads to this trace in the uh function:
(uh ((x → (list int)) ((list x) → x) ·) ·)
(uh (x (list x) ((list int) x ·)) ·)
(uh ((list int) (list x) ·) (x (list x) ·))
(uh (int x ·) (x (list x) ·))
(uh (x int ·) (x (list x) ·))
(uh · (x int (int (list int) ·)))
whereby the third step sets up a problem (that's where the
occurs check should have aborted the program) but instead, a
few steps later when we get a substitution for 'x', it
causes the second argument to not have the form of
variables-for-types substitution.
I don't think this can happen when the occurs check is in place
because the variable elimination step makes sure that we don't
set ourselves up to change the domain of anything in the second
argument to 'uh' (except possibly when the occurs check fails,
of course).
Here's an example that shows this:
(unify (q → q) (y → int)))
(uh ((q → q) (y → int) ·) ·)
(uh (q y (q int ·)) ·)
(uh (y int ·) (q y ·))
(uh · (y int (q int ·)))
In the second to last step we don't have (q int ·), we have
(y int ·) because the variable elimination step changes the
q to a y.
Invoking a non-composable, empty continuation during the right-hand
side of a variable definition skips the definition --- while continuing
the module body. The compiler assumes, however, that variable references
later in the module do not need a check that the variable is undefined.
Fix that mismatch by changing `module` to double-check that defined
variables are really defined before continuing the module body.
(The check and associated prompt are skipped in simple cases, such as
function definitions.)
A better choice is probably to move the prompt to the right-hand
side of a definition, both in a module and at the top level. That's
a much different language, though, so we should consider the point again
in some future variant of Racket.
Closes PR 14427
to be simpler and clearer
This caused bug #6's counterexample to change
because the unification algorithm no longer calls
∨ so we have to find a different way to call it
The following should look as expected now:
* Intersecting or adjacent surfaces, isosurfaces, lines and paths,
even if they're sampled at different intervals.
* Rectangles that aren't spaced regularly on the x,y plane (e.g.
sideways histograms; the rectangles I plot to debug Dr. Bayes).
In general, the rendering should be robust enough to draw arbitrary
3D scenes, and it still produces high-quality PDFs.
Drawing 3D plots still has the same time complexity and seems to be
about as fast as before. Thanks to the fact that sorting objects by
view distance is an O(n) BSP tree walk, rotating 3D plots in
DrRacket is probably a little faster.
This update also adds direct support for connected lines, and
includes a fix that makes contour lines easy to see, even when
plotted on top of a non-contour-interval surface. (This wasn't
possible before.) Further, the 3D plot area no longer requires a
"grid center" vertex by which to sort grid-aligned shapes, making
the rendering API friendlier, and closer to ready for public use.
Commit 92b0e86ed1 turns
out to have been the wrong approach, because there was no mysterious
performance problem with TR. Instead, TR's `define` expanded to new
code that interacted poorly with a macro used in the math docs.
I've kept the refactoring from that commit because I think it still
makes the code clearer, but I've removed the now extraneous comment.
After commit 3d177e454e
running the main `math.scrbl` file would show peak memory
usage of around 600-700MB when before it was around 400MB.
The proximal cause appears to be the expansion of TR
definitions, which added an extra `begin` in some cases,
combined with redefinitions at the top-level. I don't
know the core cause yet.
Thanks to Matthew for pointing out the issue and to
Vincent for helping with debugging.
self-contained (and then don't call type-check anymore
from the benchmark scripts)
this fixes a problem in the let-poly models, since some
of the bugs there cause the type-checker to raise an error
The new test case in this commit shows the bad behavior;
the fix was to replace the regexp #rx".*[^0-9]([0-9]+)$"
with #rx"([0-9]+)$", ie make the regexp work properly in
the empty case (since regexps promise to find longest matches
anyway).
Also, Rackety
The reverted commit assumed that all pkgs were in either (get-pkgs-search-dirs)
or (find-user-pkgs-dir), which is a bogus assumption
This reverts commit b600dcc7bc.
Improve the "can unbox test" to include patterns that were already covered
by the more restrictive "can unbox without disturbing N registers" test
(which is always tried first, but the weaker test recurs within patterns
that the stronger test does not recognize).
