CHEN Jian's Java Blog

implicit parameter -> using variables explicitly passed-in parameters will be passed like this: foo(using someVariable) implicit variables -> given variables implicit class -> extension Pureconfig com.github.pureconfig:pureconfig_2.13 -> com.github.pureconfig:pureconfig-generic-scala3_3 implicit def hint[T] = … -> given [T]: ProductHint[T] = … Add given ConfigReader[MyConf] = deriveReader Mockito remove org.mockito:mockito-scala because it doesn’t support scala3 mock[SomeClass] -> mock(classOf[SomeClass]) …

A list of things I changed in a Scala 2->3 upgrade Read More »

Instead it’s based on position. To be specific, the first column in the select sql will be mapped to the first property of the case class. Here is an example: Let’s say in the db there is a table called foo_bar foo bar fff bbb This is not desirable. But the author of Doobie won’t …

Note: Doobie’s row->case class mapping is not based on case class property name Read More »

It’s said IO.pure() means eager evaluation. But it doesn’t seem to so in this example: Here println(“print in pure”) is executed just like as if it’s IO.apply() Another example, however, discloses the truth Here is it how it works: When printTwice() is called, every expression inside it is evaluated IO.apply(println(“print in lazy”)) is evaluated as …

In Cats-effect, when is xxx inside IO.pure(xxx) executed? Read More »