Practical examples of using symbols in Scala?

Question

Scala has symbols - names that start with a single quote \' and which are a kind of string constants.

I know symbols from Ruby (where they start with a colon). In Ru

Answer 1

As already noted, symbols carry-over from other (more) functional languages. Something others have not mentioned is that not only do they fill the role of symbols, but they are also the closest equivalent of keywords (minus the performance advantage maybe). In my opinion, they are more useful as keywords, meaning explicit identifiers.

Below I will include a court description from Clojure docs of keywords and symbols.

Symbols

Symbols are identifiers that are normally used to refer to something else. They can be used in program forms to refer to function parameters, let bindings, class names and global vars. They have names and optional namespaces, both of which are strings. Symbols can have metadata (see with-meta).

Keywords

Keywords are symbolic identifiers that evaluate to themselves. They provide very fast equality tests. Like Symbols, they have names and optional namespaces, both of which are strings. The leading ':' is not part of the namespace or name.

Scala symbols are not as powerful as symbols in some languages. Therefore, they are not as useful either. However, I don't see why they couldn't offer the same meta-programming and performance advantages as keywords. At the very least, they can make your code easier to read.