make convert(Union{},x) directly ambiguous#46000
Merged
KristofferC merged 1 commit intomasterfrom Jul 18, 2022
Merged
Conversation
| # open, | ||
| futime, | ||
| write, | ||
| JL_O_ACCMODE, |
Member
Author
There was a problem hiding this comment.
causes a warning in the ambiguity test here (seems to have been added by mistake recently)
Collaborator
|
Your benchmark job has completed - possible performance regressions were detected. A full report can be found here. |
timholy
approved these changes
Jul 14, 2022
Member
timholy
left a comment
There was a problem hiding this comment.
This seems like a much better solution than what we were doing before.
Member
|
Thanks! |
ffucci
pushed a commit
to ffucci/julia
that referenced
this pull request
Aug 11, 2022
This should make it impossible to accidentally define or call this method on foreign types. Refs: JuliaLang#31602 Fixes: JuliaLang#45837 Closes: JuliaLang#45051
pcjentsch
pushed a commit
to pcjentsch/julia
that referenced
this pull request
Aug 18, 2022
This should make it impossible to accidentally define or call this method on foreign types. Refs: JuliaLang#31602 Fixes: JuliaLang#45837 Closes: JuliaLang#45051
vtjnash
added a commit
that referenced
this pull request
Apr 13, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
vtjnash
added a commit
that referenced
this pull request
Apr 13, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
vtjnash
added a commit
that referenced
this pull request
Apr 13, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
vtjnash
added a commit
that referenced
this pull request
Apr 18, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
vtjnash
added a commit
that referenced
this pull request
Apr 23, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
vtjnash
added a commit
that referenced
this pull request
Apr 24, 2023
Based on the new morespecific rule for Union{} and method definitions of
the specific form `f(..., Type{Union{}}, Vararg)`. If a method
definition exists with that specific form, the intersection visitor will
ignore all intersections that have that as their only result, saving
significant effort when working with lookups involving `Type{<:T}`
(which usually ended up mostly ambiguous anyways).
Fixes: #33780
This pattern turns out to have still to been making package loading
slow. We could keep adding methods following the ambiguity pattern
#46000 for the couple specific
functions that need it (constructor, eltype, IteratorEltype,
IteratorSize, and maybe a couple others) so the internals can detect
those and optimize functions that have that method pair. But it seems
somewhat odd, convoluted, and non-obvious behavior there. Instead, this
breaks all ambiguities in which Union{} is present explicitly in favor
of the method with Union{}. This means that when computing method
matches, as soon as we see one method definition with Union{}, we can
record that the method is the only possible match for that slot.
This, in essence, permits creating a rule for dispatch that a TypeVar
lower bound must be strictly a supertype of Union{}, but this creates it
at the function level, instead of expecting the user to add it to every
TypeVar they use to define methods.
This also lets us improve the error message for these cases (generally
they should error to avoid polluting the inference result), since we can
be assured this method will be called, and not result in an ambiguous
MethodError instead!
Reverts the functional change of #46000
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
6 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This should make it impossible to accidentally define or call this
method on foreign types.
Refs: #31602
Fixes: #45837
Closes: #45051
@nanosoldier
runbenchmarks(!"scalar", vs=":master")