F#: Double backticked value names clash with function names?

Question

In Visual Studio 2015:

let myFunction (``string`` : string) =
    "\"Quoted string\"" |> (Regex "\"[^\"]*\"").Match |> string

let myOtherFunction (str : string) =
    "\"Quoted string\"" |> (Regex "\"[^\"]*\"").Match |> string

First function generates a compiler error, the string function is underlined in red. ("This expression was expected to have type Match -> 'a but here has type string")

Second function is fine, no problems.

Is this by design?

Answer 1

The reason is, your parameter and the call at the end are the same thing. Double backticks are used to escape the name, they are not part of the name.

So in your case that means that ``string`` and string are exactly the same thing, you are trying to pipe into your string parameter. And yes, this is totally by design.

The C# equivalent are @-escaped names, where for example @hello and hello would clash.