Tricky behaviours

This section explores aspects of Scala that break reasonable expectations or cause cryptic compilation errors. They’re easily avoided if you know about them, but have been known to mystify beginners and more advanced developers alike.

Content

• Add explicit type annotations to implicits
• Avoid unicode versions of ASCII operators
• Do not concatenate Strings with +
• Make implicit names as unique as possible
• Make subtypes of sealed types final
• Mark case classes as final
• Start independent Futures outside of a for-comprehension