Merge branch 'scala:main' into main

Author: benluo

_overviews/scala-book/sbt-scalatest-bdd.md

@@ -45,9 +45,9 @@ Next, create a file named *MathUtilsTests.scala* in the *src/test/scala/simplete
 ```scala
 package simpletest
 
-import org.scalatest.FunSpec
+import org.scalatest.funspec.AnyFunSpec
 
-class MathUtilsSpec extends FunSpec {
+class MathUtilsSpec extends AnyFunSpec {
 
     describe("MathUtils::double") {
 

_sips/sips/binary-integer-literals.md

@@ -0,0 +1,33 @@
+---
+layout: sip
+title: SIP-42 - Support Binary Integer Literals
+stage: implementation
+status: waiting-for-implementation
+permalink: /sips/:title.html
+---
+
+**By: NthPortal**
+
+## History
+
+| Date          | Version                  |
+|---------------|--------------------------|
+| Jul 27th 2019 | Initial Draft            |
+
+Your feedback is welcome! If you're interested in discussing this proposal, head over to [this](https://contributors.scala-lang.org/t/pre-sip-binary-literals/3559) Scala Contributors thread and let me know what you think.
+
+## Proposal
+
+Support binary integer literals. For example, the binary literal `0b00101010` would have the integer value `42`.
+
+## Motivation
+
+Several other major languages support binary integer literals, including [Java](https://docs.oracle.com/javase/specs/jls/se12/html/jls-3.html#jls-3.10.1) (as of [Java 7](https://docs.oracle.com/javase/specs/jls/se7/html/jls-3.html#jls-3.10.1)), [Kotlin](https://kotlinlang.org/docs/reference/basic-types.html#literal-constants), [Python](https://docs.python.org/3/reference/lexical_analysis.html#integer-literals) and [Rust](https://doc.rust-lang.org/stable/reference/tokens.html#number-literals).
+
+## Interactions with Other Language Features
+
+Like other integer literals, binary integer literals support separators (`_`), which can greatly enhance the readability of larger values (e.g. `0b_1110_1101_1011_0111`).
+
+## Implementation
+
+The implementation of binary integer literals is quite simple, and can be found at <https://github.com/scala/scala/pull/8275>.

_sips/sips/support-binary-integer-literals.md

@@ -116,7 +116,7 @@ We've seen we can accomplish covariance by making sure that we can't put somethi
 
 We say that `Serializer` is *contravariant* in `A`, and this is indicated by the `-` before the `A`. A more general serializer is a subtype of a more specific serializer.
 
-More formally, that gives us the reverse relationship: given some `class Contra[-T]`, then if `A` is a subtype of `B`, `Cov[B]` is a subtype of `Cov[A]`. 
+More formally, that gives us the reverse relationship: given some `class Contra[-T]`, then if `A` is a subtype of `B`, `Contra[B]` is a subtype of `Contra[A]`. 
 
 ### Comparison With Other Languages