softwaremill/quicklens

Doesn't work with literal type

user753 opened this issue · 3 comments

user753 commented

scala 3.2.2
quicklens v1.9.2

case class Test(f: "foo")
Test("foo").modify(_.f).setTo("foo")
[error]    |  Test("foo").modify(_.f).setTo("foo")
[error]    |  ^^^^^^^^^^^^^^^^^^^^^^^
[error]    |  Found:    String
[error]    |  Required: ("foo" : String)

  Test("foo").modify(_.f).setTo("foo": "foo")

also doesn't work

KacperFKorban commented

Now it should be possible to do

case class Test(f: "foo")
Test("foo").modify["foo"](_.f).setTo("foo")
user753 commented

Thanks.
Is it the compiler limitation that the generic type need to be specified?

Test("foo").modify(_.f)

Found:    String
Required: ("foo" : String)
KacperFKorban commented

The issue is with type inference. The compiler infers the type parameter of modify to be String. In general, the compiler avoids inferring singleton types ATM. It's not necessarily a limitation, but a design choice.

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