anchor.diff:      let inline get (str : string) (index : int) =
           str.[index]
   
  -    /// Indicates whether the specified string is null or empty.
  -    [<CompiledName("IsNullOrEmpty")>]
  -    let inline isNullOrEmpty str =
  -        System.String.IsNullOrEmpty str
  -
       /// Indicates whether the specified string is empty.
       [<CompiledName("IsEmpty")>]
       let inline isEmpty (str : string) =
           str.Length < 1
  +
  +    /// Creates a string from an F# option value.
  +    /// If the option value is <c>None</c>, returns an empty string;
  +    /// returns <c>s</c> when the option value is <c>Some s</c>
  +    [<CompiledName("OfOption")>]
  +    let inline ofOption value =
  +        match value with
  +        | None -> empty
  +        | Some str -> str
  +
  +    /// Builds a string from the given character array.
  +    [<CompiledName("OfArray")>]
  +    let inline ofArray (chars : char[]) =
  +        System.String (chars)
  +
  +    /// Creates an F# option value from the specified string.
  +    /// If the string 's' is null or empty, returns None; otherwise, returns Some s.
  +    [<CompiledName("ToOption")>]
  +    let inline toOption str =
  +        if System.String.IsNullOrEmpty str then None
  +        else Some str
  +
  +    /// Builds a character array from the given string.
  +    [<CompiledName("ToArray")>]
  +    let inline toArray (str : string) =
  +        str.ToCharArray ()
  +
  +    /// Returns a string array that contains the substrings in a string that are delimited
  +    /// by elements of the given Unicode character array.
  +    [<CompiledName("Split")>]
  +    let inline split (chars : char[]) (str : string) =
  +        str.Split chars
   
       /// <summary>Returns a new string created by concatenating the strings in the specified string array.</summary>
       /// <remarks>
  
positive.code:     let inline toLines (str : string) =
          str.Split ([| '\r'; '\n' |], System.StringSplitOptions.RemoveEmptyEntries)
  
      /// Creates a string from an F# option value.
      /// If the option value is <c>None</c>, returns an empty string;
      /// returns <c>s</c> when the option value is <c>Some s</c>
      [<CompiledName("OfOption")>]
      let inline ofOption value =
          match value with
          | None -> empty
          | Some str -> str
  
      /// Creates an F# option value from the specified string.
      /// If the string 's' is null or empty, returns None; otherwise, returns Some s.
      [<CompiledName("ToOption")>]
      let inline toOption str =
          if System.String.IsNullOrEmpty str then None
          else Some str
  
      /// Creates a new string by removing all leading and
      /// trailing white-space characters from a string.
      [<CompiledName("Trim")>]
      let inline trim (str : string) =
          str.Trim ()
  
      /// Removes all leading and trailing occurrences of
      /// the specified characters from a string.
      [<CompiledName("TrimChars")>]
      let inline trimChars (chars : char[]) (str : string) =
          str.Trim chars
  
      /// Builds a character array from the given string.
      [<CompiledName("ToArray")>]
      let inline toArray (str : string) =
          str.ToCharArray ()
  
      /// Builds a string from the given character array.
      [<CompiledName("OfArray")>]
      let inline ofArray (chars : char[]) =
          System.String (chars)
  
      /// Gets a substring of a string.
      [<CompiledName("Sub")>]
      let inline sub (str : string) offset count : substring =
  
negative.code:                     chosenCount <- chosenCount + 1
  
              // Create a new string from the chosen characters.
              ofArray chosenChars.[..chosenCount-1]
  
      /// Creates a new string by removing all leading and
      /// trailing white-space characters from a string.
      [<CompiledName("Trim")>]
      let inline trim (str : string) =
          str.Trim ()
  
      /// Removes all leading and trailing occurrences of
      /// the specified characters from a string.
      [<CompiledName("TrimChars")>]
      let inline trimChars (chars : char[]) (str : string) =
          str.Trim chars
  
      /// Removes all leading occurrences of the specified set of characters from a string.
      [<CompiledName("TrimStart")>]
  