"match" expressions

A match expression branches based on a single value. It can be any numeric type.

match is an expression and can be nested inside other expressions.

Branches of the match can be squeezed onto one line using then.

The argument to match can introduce a local.

A symbol is a simple value that can tested against other symbol values using ==.
Like an enum value, this kind of value is intended to be used for its identity.
You can't directly access the characters in a symbol, although it can be converted to or from a string using to.

Think of the symbol type as an infinitely large enum supporting all possible values.
This makes it useful when you don't know all possible values up-front.

If you are dealing with a limited set of values with likely repetition, you should usually use a symbol.
For example, the keys of a json object are symbols.

match works on symbol and string values too.

String values may be unquoted (as in as left below) if they are valid Keen identifiers.
Otherwise they should be quoted like regular string literals.

match also works on char8 or char32.

Unlike with an if expression, a match expression on a number or string-like type must have an else branch.
The reason is that match expressions are usually used with an enum or union, and in those cases no else is required.
This will be explained in Enums and flags and Unions.