Allow to beta reduce curried function applications in quotes reflect #18121
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| tpd.Apply(tpd.Select(expr1, nme), args) | ||
| ).withSpan(tree.span) | ||
| } | ||
| case tpd.Apply(tpd.TypeApply(tpd.Select(expr: Apply, nme), tpts), args) => |
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This logic is becoming a bit ad-hoc. I feel that my original design was not the best.
I wonder if we could simplify this using a TreeMap. I have something like this in mind. Though I have not tested it.
val tree1 = new TreeMap {
def transform(tree: Tree)(using Context): Tree = tree match {
case tpd.Block(Nil, _) | tpd.Inlined(_, Nil, _) => super.transform(tree)
case _: tpd.Apply | _: tpd.TypeApply =>
val tree1 = super.transform(tree)
if tree.tpe.isInstanceOf[MethodicType] then tree1
else dotc.transform.BetaReduce(tree1).withSpan(tree.span)
case _ => tree
}
}.transform(tree)
if tree1 eq tree then None else Some(tree1)There was a problem hiding this comment.
I replaced this with a TreeMap now but I was unable to simplify the overall logic there by much (but at the very least the Block and Inlined cases are simpler)
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| * To retain semantics the argument `ei` is bound as `val yi = ei` and by-name arguments to `def yi = ei`. | ||
| * Some bindings may be elided as an early optimization. | ||
| * | ||
| * Example: |
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I still belive this is to complex for a first-time user. I would call this the general rule.
| * Example: | |
| * Generally: |
I would add a trivial beta reduction example before this.
Example:
```scala sc:nocompile
((a: Int, b: Int) => a + b).apply(x, y)
```
will be reduced to
```scala sc:nocompile
val a = x
val b = y
a + b
```
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Oh, I see that you did that in the other file. We should have the same example in both documentations. I believe that my new example will be better for new users that are less experienced.
Previously, the curried functions with multiple applications were not able to be beta-reduced in any way, which was unexpected. Now we allow reducing any number of top-level function applications for a curried function. This was also made clearer in the documentation for the affected (Expr.betaReduce and Term.betaReduce) methods.
|
@nicolasstucki Sorry for the (very) delayed update on this, today I have finally updated the documentation as suggested |
Closes #17506
Previously, the curried functions with multiple applications were not able to be beta-reduced in any way, which was unexpected. Now, we allow reducing any number of top-level function applications for a top-level curried function. This was also made clearer in the documentation for the affected (
Expr.betaReduceandTerm.betaReduce) methods.I've extended the test provided by the minimisation from the above issue with multiple additional tests for beta reduction with type parameters and more-than-two curried function applications.