F# 프로그래밍에서 정수인지 부동소수점수인지 구분하기

필요한데가 많을 것 같아서 올려 놓는다.

//  See  http://msdn.microsoft.com/en-us/library/dd233248.aspx

let (|Integer|_|) (str: string) =
   let mutable intvalue = 0
   if System.Int32.TryParse(str, &intvalue) then Some(intvalue)
   else None

let (|Float|_|) (str: string) =
   let mutable floatvalue = 0.0
   if System.Double.TryParse(str, &floatvalue) then Some(floatvalue)
   else None

let parseNumeric str =
   match str with
     | Integer i -> printfn "%d : Integer" i
     | Float f -> printfn "%f : Floating point" f
     | _ -> printfn "%s : Not matched." str

parseNumeric "1.1"
parseNumeric "0"
parseNumeric "0.0"
parseNumeric "10"
parseNumeric "Something else"

실행 결과:

1.100000 : Floating point
0 : Integer
0.000000 : Floating point
10 : Integer
Something else : Not matched.