In F# you can pass a string to an int via the |> operator like this:
"54" |> int
I was wondering if there is a way to do that for list like this:
"[4;2;3]" |> list
When trying to do this for a list it errors that the value or constructor is not defined.
Perhaps this is not possible at all?
int is a function that can convert a string (and other things) into an int.
There is no built-in function called list. To make a list you could use the list literal syntax: [4;2;3]
If you need to parse a string like "[4;2;3]" into an int list then you're on your own. You'd need to write code to do that. For example:
let parseIntList (str:string) =
let trimmed = str.Trim()
if not (trimmed.StartsWith "[" && trimmed.EndsWith "]") then failwith "Not a list"
trimmed.[1 .. trimmed.Length - 2].Split ';'
|> Array.map int
|> Array.toList
This function works for your example but it may fail for other valid inputs.
int is a constructor that can construct an int from a string ?
int, it is indeed not a constructor, but wraps the static Int32.Parse (did not manage to find the source code location yet)
