Dmitry Savvinov
44920f42d8
Consider following case:
fun foo(): Unit = run { "hello" }
Previously, NI would analyze lambda body without expected type, because
it is a type variable 'R' from 'run', which hasn't been fixed yet. This
leads to treating "hello" as lambda-return argument and adding bogus
'String' constraint on 'R', and, consequently, type mismatch.
Now, we peek into current constraint system and check if return-type of
lambda is type variable with upper-Unit constraint (which is exactly
condition for its body to be Unit-coerced). If so, then we provide
expected Unit-type for body explicitly, and the rest will be done
automatically (in particular, in aforementioned example "hello" wouldn't
be treated as lambda return argument).
26 lines
562 B
Kotlin
Vendored
26 lines
562 B
Kotlin
Vendored
// !WITH_NEW_INFERENCE
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// !CHECK_TYPE
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fun noCoercionLastExpressionUsedAsReturnArgument() {
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val a = {
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42
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}
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a checkType { _<() -> Int>() }
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}
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fun noCoercionBlockHasExplicitType() {
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val <!UNUSED_VARIABLE!>b<!>: () -> Int = {
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<!TYPE_MISMATCH!>if (true) <!UNUSED_EXPRESSION!>42<!><!>
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}
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}
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fun noCoercionBlockHasExplicitReturn() {
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val <!UNUSED_VARIABLE!>c<!> = l@{
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if (true) return@l 42
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<!INVALID_IF_AS_EXPRESSION!>if<!> (true) 239
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}
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}
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fun noCoercionInExpressionBody(): Unit = <!TYPE_MISMATCH!>"hello"<!> |