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author | Martin Odersky <odersky@gmail.com> | 2014-03-16 17:30:04 +0100 |
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committer | Tobias Schlatter <tobias@meisch.ch> | 2014-03-21 11:24:03 +0100 |
commit | ee1251f37f844bdb4f4ea69177e8183ad74e7b3d (patch) | |
tree | 9540aad09833958cd80de1ddc7cc8087ba943f3e /tests/pos | |
parent | bb90b26fbca27f432ade46ae572b82e1b8027b19 (diff) | |
download | dotty-ee1251f37f844bdb4f4ea69177e8183ad74e7b3d.tar.gz dotty-ee1251f37f844bdb4f4ea69177e8183ad74e7b3d.tar.bz2 dotty-ee1251f37f844bdb4f4ea69177e8183ad74e7b3d.zip |
Fix of t0438 - lambdas and eta expansion
Two fixes were needed
1) When typing a function value (x1: T1, ..., xN: Tn) => e, don't unconditionally issue an error
if the expected function type arity is different from N. Instead, issue an error only
if one of the types T1, ..., Tn is absent. The idea is that only then we need to
consult the expected type for the parameter type. This allows to fix the problem later
by an implicit conversion applied to the function value.
2) When eta-expanding, do not automtically take the arity of the expected function value as the
arity of the generated lambda. Instead, take the method's arity, and copy method parameters
into the lambda in case the arities are different.
Diffstat (limited to 'tests/pos')
-rw-r--r-- | tests/pos/t0438.scala | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/tests/pos/t0438.scala b/tests/pos/t0438.scala new file mode 100644 index 000000000..1615e3da7 --- /dev/null +++ b/tests/pos/t0438.scala @@ -0,0 +1,12 @@ +class Foo { + implicit def pair2fun2[A, B, C](f: (A, B) => C): ((A, B)) => C = + {p: (A, B) => f(p._1, p._2) } + + def foo(f: ((Int, Int)) => Int) = f + def bar(x: Int, y: Int) = x + y + + foo(((x: Int, y: Int) => x + y)) // works + foo(pair2fun2(bar _)) // works + foo(bar _) // error + foo(bar) // same error +} |