F# keyword 'Some'

Question

F# keyword \'Some\' - what does it mean?

Answer 1

Some is used to specify an option type, or in other words, a type that may or may not exist.

F# is different from most languages in that control flow is mostly done through pattern matching as opposed to traditional if/else logic.

In traditional if/else logic, you may see something like this:

if (isNull(x)) {
   do ...  
} else {         //x exists
   do ...  
}

With pattern matching logic, matching we need a similar way to execute certain code if a value is null, or in F# syntax, None

Thus we would have the same code as

match x with 
  | None -> do ...
  | Some x -> do ...