| Commit message (Collapse) | Author | Age | Files | Lines |
|---|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
During large compilations runs, the large numbers of globally unique
fresh names for existentials captured from prefixes of `asSeenFrom`.
is a) somewhat wasteful (all these names are interned in the name table)
, and, b) form a pathological case for the current implementation of
`Names#hashValue`, which leads to overfull hash-buckets in the name table.
`hashValue` should probably be improved, but my attempts to do so have
shown a small performance degradation in some benchmarks. So this commit
starts by being more frugal with these names, only uniquely naming
within an `asSeenFrom` operation.
References scala/scala-dev#246
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
- Avoid calling NoSymbol.owner when checking whether we're
dealing with a case class constructor pattern or a general
extractor. Tested manually with the test case in the ticket,
no more output is produced under `-Xdev`.
- Be more conservative about the conversion to a case class
pattern: rather than looking just at the type of the pattern
tree, also look at the tree itself to ensure its safe to
elide. This change is analagous to SI-4859, which restricted
rewrites of case apply calls to case constructors.
I've manually tested that case class patterns are still efficiently
translated:
```
object Test {
def main(args: Array[String]) {
Some(1) match { case Some(x) => }
}
}
```
```
% qscalac -Xprint:patmat sandbox/test.scala
[[syntax trees at end of patmat]] // test.scala
package <empty> {
object Test extends scala.AnyRef {
def <init>(): Test.type = {
Test.super.<init>();
()
};
def main(args: Array[String]): Unit = {
case <synthetic> val x1: Some[Int] = scala.Some.apply[Int](1);
case4(){
if (x1.ne(null))
matchEnd3(())
else
case5()
};
case5(){
matchEnd3(throw new MatchError(x1))
};
matchEnd3(x: Unit){
x
}
}
}
}
```
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Typechecking constructor patterns of method local case classes
was only working because of the existence of the unapply method
in the companion, which is used if navigation to the case class
companion object fails.
We now support defintion of, and pattern matching on, case classes
with more than 22 parameters. These have no `unapply` method
in the companion, as we don't have a large enough tuple type to
return. So for such case classes, the fallback that we inadvertently
relied on would no longer save us, and we'd end up with a compile
error advising that the identifier in the constructor pattern was
neither a case class nor an extractor.
This is due to the propensity of `Symbol#companionXxx` to return
`NoSymbol` when in the midst of typechecking. That method should
only be relied upon after typechecking. During typechecking,
`Namers#companionSymbolOf` should be used instead, which looks in the
scopes of enclosing contexts for symbol companionship. That's
what I've done in this commit.
|
| | |
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
- Added `since` to deprecation statement
- Added unit to parameter list
- Removed usage of deprecated method polyType
- Replaced deprecated `debugwarn` with `devWarning`
- Changed switch statement to if else in order to remove a warning
- Switched implementation of `init` and `processOptions` to prevent
warning
- Replaced deprecated `Console.readLine` with `scala.io.StdIn.readLine`
- Replaced deprecated `startOrPoint` with `start`
- Replaced deprecated `tpe_=` with `setType`
- Replaced deprecated `typeCheck` with `typecheck`
- Replaced deprecated `CompilationUnit.warning` with `typer.context.warning`
- Replaced deprecated `scala.tools.nsc.util.ScalaClassLoader` with `scala.reflect.internal.util.ScalaClassLoader`
- Replaced deprecated `scala.tools.ListOfNil` with `scala.reflect.internal.util.ListOfNil`
- Replaced deprecated `scala.tools.utils.ScalaClassLoader` with `scala.reflect.internal.util.ScalaClassLoader`
- Replaced deprecated `emptyValDef` with `noSelfType`
- In `BoxesRunTime` removed unused method and commented out unused values. Did not delete to keep a reference to the values. If they are deleted people might wonder why `1` and `2` are not used.
- Replaced deprecated `scala.tools.nsc.util.AbstractFileClassLoader` with `scala.reflect.internal.util.AbstractFileClassLoader`
|
| |
|
|
|
|
|
|
|
|
|
|
|
| |
This commit corrects many typos found in scaladocs, comments and
documentation. It should reduce a bit number of PRs which fix one
typo.
There are no changes in the 'real' code except one corrected name of
a JUnit test method and some error messages in exceptions. In the case
of typos in other method or field names etc., I just skipped them.
Obviously this commit doesn't fix all existing typos. I just generated
in IntelliJ the list of potential typos and looked through it quickly.
|
| |
|
|
|
|
| |
doesn't leak uncatchable errors. Interestingly enough, the problem
only manifested itself for custom unapply methods, not for synthetic
ones generated for case classes.
|
| |
|
|
|
|
|
|
|
|
| |
In this case, `infer.issue -> context.issue`.
Forwarders are dead weight that cause bit rot.
They tend to acquire functionality,
clutter their defining interface and
dilute the purpose of the method they forward to.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This commit does not close SI-5900. It only addresses a regression
in 2.11 prereleases caused by SI-7886.
The fix for SI-7886 was incomplete (as shown by the last commit)
and incorrect (as shown by the regression in pos/t5900a.scala and
the fact it ended up inferring type parameters.)
I believe that the key to fixing this problem will be unifying
the inference of case class constructor patterns and extractor
patterns.
I've explored that idea:
https://gist.github.com/retronym/7704153
https://github.com/retronym/scala/compare/ticket/5900
But didn't quite get there.
|
| |
|
|
|
|
|
|
| |
Name-based pattern matcher needed some hardening against
unapply methods with the right name but wrong types. Only
isEmpty methods which return Boolean are acceptable.
Catching it directly rather than indirectly also allowed
for better error messages.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This emerges from a recent attempt to eliminate pattern matcher
related duplication and to bake the scalac-independent logic
out of it. I had in mind something a lot cleaner, but it was
a whole lot of work to get it here and I can take it no further.
Key file to admire is PatternExpander.scala, which should
provide a basis for some separation of concerns.
The bugs addressed are a CCE involving Tuple1 and an imprecise
warning regarding multiple pattern crushing.
Editorial: auto-tupling unapply results was a terrible idea which
should never have escaped from the crib. It is tantamount to
purposely throwing type safety down the toilet in the very place
where people need type safety the most. See SI-6111 and SI-6675 for
some other comments.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
This commit introduces internal attachment that allows unapply macros to
be aware of their sub patterns and tweak their expansion depending
on that info.
At the moment this is not possible due to the way pattern macros are
expanded:
case MacroPat(inner1, inner2) => ...
During type checking this will expand as
MacroPat.unapply(<unapply-dummy>)
Meaning that macro can’t see inner1 and inner2 in it’s macroApplication.
To circumvent this we attach that info as an attachment to the dummy.
|
| |
|
|
|
|
| |
When an application of a blackbox macro is used as an extractor in a
pattern match, it triggers an unconditional compiler error,
preventing customizations of pattern matching implemented with macros.
|
| |
|
|
|
|
|
|
| |
This commit extracts out freshTermName and freshTypeName to the top-level
with implicit fresh name creator argument. This will let to refactor out
more methods out of tree builder into treegen that are dependent on fresh
name generator. We also save quite a bit of boilerplate by not having to
redefined fresh functions all over the place.
|
| |\
| |
| | |
SI-7886 unsoundness in pattern matcher.
|
| | |
| |
| |
| |
| |
| |
| | |
Introduces -Xstrict-inference to deal with the significant
gap between soundness and what presently compiles. I'm hopeful
that it's TOO strict, because it finds e.g. 75 errors compiling
immutable/IntMap.scala, but it might be that bad.
|
| | |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
| | |
I tracked down what was behind the issue described here:
// TODO: fix the illegal type bound in pos/t602 -- type inference
// messes up before we get here:
/*override def equals(x$1: Any): Boolean = ...
// Span[Any] --> Any is not a legal type argument for Span!
val o5: Option[com.mosol.sl.Span[Any]] =
*/
...which led straight to the unsoundness seen in neg/t7886.
It is dangerous to have an expected type of "Any" because
the type system will blithely ignore kind errors, since "Any"
can absorb anything. The consequence in this instance was
that inferring the case constructor for a type like
Foo[T <: Bound]
if done with expected type Any, this would come up with Foo[Any].
I altered it to use expected type Foo[T], which lets the dummy
type parameter survive to carry the bound forward and restores
sense to the inference. The before/after output for -Xprint:patmat
on pos/t602.scala is:
15c15
< if (x1.isInstanceOf[com.mosol.sl.Span[Any]])
---
> if (x1.isInstanceOf[com.mosol.sl.Span[K]])
17c17
< <synthetic> val x2: com.mosol.sl.Span[Any] = \
(x1.asInstanceOf[com.mosol.sl.Span[Any]]: com.mosol.sl.Span[Any]);
---
> <synthetic> val x2: com.mosol.sl.Span[K] = \
(x1.asInstanceOf[com.mosol.sl.Span[K]]: com.mosol.sl.Span[K]);
19,20c19,20
< val low$0: Option[Any] = x2.low;
< val high$0: Option[Any] = x2.high;
---
> val low$0: Option[K] = x2.low;
> val high$0: Option[K] = x2.high;
A file in the library depended (needlessly) on the unsoundness.
It was easy to fix but reminds us this may affect existing code.
|
| |/
|
|
|
|
|
| |
Most of this was revealed via -Xlint with a flag which assumes
closed world. I can't see how to check the assumes-closed-world
code in without it being an ordeal. I'll leave it in a branch in
case anyone wants to finish the long slog to the merge.
|
| |
|
|
|
|
|
|
|
|
| |
Without it, the enclosed test fails with:
ArrayBuffer(Problem(RangePosition(partial-fun/src/PartialFun.scala, 62, 62, 77),type mismatch;
found : Int => Int
required: PartialFunction[Int,Int],2))
And with that, we can remove this option altogether.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
| |
Reduced the amount of extraneous logging noise at the
default logging level.
Was brought to my usual crashing halt by the discovery of identical
logging statements throughout GenASM and elsewhere. I'm supposing
the reason people so grossly underestimate the cost of such duplication
is that most of the effects are in things which don't happen, aka
"silent evidence".
An example of a thing which isn't happening is the remainder of
this commit, which exists only in parallel universes.
|
| |
|
|
|
|
|
|
| |
This fleshes out some of the slightly unfinished corners
of the adventure, especially for unapplySeq. There's still
an unhealthy amount of duplication and a paucity of
specification, but I think it's in eminently good shape
for a milestone.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
Establishes a pattern that can be used to implement extractor macros
that give the programmer control over signatures of unapplications
at compile-time.
=== The pattern ===
In a nutshell, given an unapply method (for simplicity, in this
example the scrutinee is of a concrete type, but it's also possible
to have the extractor be polymorphic, as demonstrated in the tests):
```
def unapply(x: SomeType) = ???
```
One can write a macro that generates extraction signatures for unapply
on per-call basis, using the target of the calls (c.prefix) and the type
of the scrutinee (that comes with x), and then communicate these signatures
to the typechecker.
For example, here's how one can define a macro that simply passes
the scrutinee back to the pattern match (for information on how to
express signatures that involve multiple extractees, visit
https://github.com/scala/scala/pull/2848).
```
def unapply(x: SomeType) = macro impl
def impl(c: Context)(x: c.Tree) = {
q"""
new {
class Match(x: SomeType) {
def isEmpty = false
def get = x
}
def unapply(x: SomeType) = new Match(x)
}.unapply($x)
"""
}
```
In addition to the matcher, which implements domain-specific
matching logic, there's quite a bit of boilerplate here, but
every part of it looks necessary to arrange a non-frustrating dialogue
with the typer. Maybe something better can be done in this department,
but I can't see how, without introducing modifications to the typechecker.
Even though the pattern uses structural types, somehow no reflective calls
are being generated (as verified by -Xlog-reflective-calls and then
by manual examination of the produced code). That's a mystery to me, but
that's also good news, since that means that extractor macros aren't
going to induce performance penalties.
Almost. Unfortunately, I couldn't turn matchers into value classes
because one can't declare value classes local. Nevertheless,
I'm leaving a canary in place (neg/t5903e) that will let us know
once this restriction is lifted.
=== Use cases ===
In particular, the pattern can be used to implement shapeshifting
pattern matchers for string interpolators without resorting to dirty
tricks. For example, quasiquote unapplications can be unhardcoded now:
```
def doTypedApply(tree: Tree, fun0: Tree, args: List[Tree], ...) = {
...
fun.tpe match {
case ExtractorType(unapply) if mode.inPatternMode =>
// this hardcode in Typers.scala is no longer necessary
if (unapply == QuasiquoteClass_api_unapply) macroExpandUnapply(...)
else doTypedUnapply(tree, fun0, fun, args, mode, pt)
}
}
```
Rough implementation strategy here would involve writing an extractor
macro that destructures c.prefix, analyzes parts of StringContext and
then generates an appropriate matcher as outlined above.
=== Implementation details ===
No modifications to core logic of typer or patmat are necessary,
as we're just piggybacking on https://github.com/scala/scala/pull/2848.
The only minor change I introduced is a guard against misbehaving
extractor macros that don't conform to the pattern (e.g. expand into
blocks or whatever else). Without the guard we'd crash with an NPE,
with the guard we get a sane compilation error.
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
An extractor is no longer required to return Option[T], and
can instead return anything which directly contains methods
with these signatures:
def isEmpty: Boolean
def get: T
If the type of get contains methods with the names of
product selectors (_1, _2, etc.) then the type and arity
of the extraction is inferred from the type of get. If
it does not contain _1, then it is a single value
extractor analogous like Option[T].
This has significant benefits and opens new territory:
- an AnyVal based Option-like class can be used which
leverages null as None, and no allocations are necessary
- for primitive types the benefit is squared (see below)
- the performance difference between case classes and
extractors should now be largely eliminated
- this in turn allows us to recapture great swaths of
memory which are currently squandered (e.g. every
TypeRef has fields for pre and args, even though these
are more than half the time NoPrefix and Nil)
Here is a primitive example:
final class OptInt(val x: Int) extends AnyVal {
def get: Int = x
def isEmpty = x == Int.MinValue // or whatever is appropriate
}
// This boxes TWICE: Int => Integer => Some(Integer)
def unapply(x: Int): Option[Int]
// This boxes NONCE
def unapply(x: Int): OptInt
As a multi-value example, after I contribute some methods to TypeRef:
def isEmpty = false
def get = this
def _1 = pre
def _2 = sym
def _3 = args
Then it's extractor becomes
def unapply(x: TypeRef) = x
Which, it need hardly be said, involves no allocations.
|
| |
|
|
| |
To be put to use in a commit shortly to follow.
|
| |
|
|
| |
Should be behaviorally neutral.
|
| |
|
|
|
|
| |
Again moving pattern-typing logic out of Typers.
You can tell I like writing Typers#Typer#typedTyped.
|
|
|
To the extent possible this commit is purely the extraction
of those methods into the newly created PatternTypers trait.
The slicing and dicing of those methods will follow shortly.
|
