conversion.vb

大名鼎鼎的mono是.NET平台的跨平台（支持linux

                        Return Oct(Convert.ToSByte(Number))
                    Case TypeCode.UInt16
                        Return Oct(Convert.ToUInt16(Number))
                    Case TypeCode.UInt32
                        Return Oct(Convert.ToUInt32(Number))
                    Case TypeCode.UInt64
                        Return Oct(Convert.ToUInt64(Number))
#End If
                    Case Else
                        Throw New System.ArgumentException("Argument 'Number' cannot be converted to type '" + Number.GetType.FullName + "'.")

                End Select
            Else
                Throw New System.ArgumentException("Argument 'Number' is not a number.")
            End If
        End Function

        Public Function Oct(ByVal Number As Short) As String
            Return Convert.ToString(Number, 8).ToUpper
        End Function

        Public Function Str(ByVal Number As Object) As String
            If Number Is Nothing Then
                Throw New System.ArgumentNullException("Number", "Value cannot be null.")
            End If

            If TypeOf Number Is Byte Then
                If Convert.ToByte(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Short Then
                If Convert.ToInt16(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Integer Then
                If Convert.ToInt32(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Long Then
                If Convert.ToInt64(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Double Then
                If Convert.ToDouble(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Decimal Then
                If Convert.ToDecimal(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is Single Then
                If Convert.ToSingle(Number) > 0 Then
                    Return " " + Convert.ToString(Number, CultureInfo.InvariantCulture)
                Else
                    Return Convert.ToString(Number, CultureInfo.InvariantCulture)
                End If
            ElseIf TypeOf Number Is String Then
                Throw New System.NullReferenceException("Object reference not set to an instance of an object.")
            Else
                Throw New System.InvalidCastException("Argument 'Number' cannot be converted to a numeric value.")
            End If
        End Function
        Public Function Val(ByVal Expression As Char) As Integer
            'only '0' - '9' are acceptable
            If Strings.Asc(Expression) >= Strings.Asc("0"c) And Strings.Asc(Expression) <= Strings.Asc("9"c) Then
                Return Strings.Asc(Expression) - Strings.Asc("0"c)
            Else
                'everything else is 0
                Return 0
            End If
        End Function
        Public Function Val(ByVal Expression As Object) As Double
            If Expression Is Nothing Then
                Return Val("")
            End If

            If TypeOf Expression Is Char Then
                Return Val(Convert.ToChar(Expression))
            ElseIf TypeOf Expression Is String Then
                Return Val(Convert.ToString(Expression))
            ElseIf TypeOf Expression Is Boolean Then
                Return Val(Convert.ToString((-1) * Convert.ToInt16(Expression)))
                'FIXME: add more types. Return Val(StringType.FromObject(Expression))
            Else
                Throw New System.ArgumentException("Argument 'Expression' cannot be converted to type '" + Expression.GetType.FullName + "'.")
            End If
        End Function
        Public Function Val(ByVal InputStr As String) As Double

            If InputStr Is Nothing Then
                InputStr = ""
            End If

#If TRACE Then
            Console.WriteLine("TRACE:Conversion.Val:input:" + InputStr)
#End If

            '
            ' loop on InputStr chars
            Dim pos As Integer              ' char iterator
            Dim CurrentChar As Char         ' current char
            Dim CurrentCharAsc As Integer   ' current ascii value of char

            Dim NumericString As String = ""
            Dim PeriodCollected As Boolean ' did we already collected a Period ?

            ' Is it a positive/negative decimal or Hex or Oct
            ' start as negative. the first one who turns into True, wins.
            Dim IsNegative As Boolean = False
            Dim IsDecimal As Boolean = False
            Dim IsHex As Boolean = False
            Dim IsOct As Boolean = False
            Dim IsE As Boolean

            '
            ' Loop on string and decide what is the base of the number.
            ' trim all left whitespace 
            '
            For pos = 0 To InputStr.Length - 1

                CurrentChar = Convert.ToChar(InputStr.Substring(pos, 1))

                If System.Char.IsWhiteSpace(CurrentChar) Then
                    'do nothing. continue
                ElseIf System.Char.IsDigit(CurrentChar) Then
                    'its decimal. exit loop
                    IsDecimal = True
                    pos = InputStr.Length
                ElseIf CurrentChar = "-" Then
                    IsNegative = True
                ElseIf CurrentChar = "&" Then
                    'if this is not the last char, 
                    'take the next char and see if radix is H or O
                    If pos < InputStr.Length - 1 Then
                        CurrentChar = Convert.ToChar(InputStr.Substring(pos + 1, 1))
                        If CurrentChar = "H" Or CurrentChar = "h" Then
                            'its Hex. exit loop
                            IsHex = True
                            pos = InputStr.Length
                        ElseIf CurrentChar = "O" Or CurrentChar = "o" Then
                            'its Oct. exit loop
                            IsOct = True
                            pos = InputStr.Length
                        Else
                            'its bad. return 0.
                            Return 0
                        End If
                    End If
                Else
                    'the string didn't start with a digit or &H or &O
                    'its bad. return 0.
                    Return 0
                End If
            Next


#If TRACE Then
            Console.WriteLine("TRACE:Conversion.Val:IsDecimal:" + IsDecimal.ToString() + "IsHex:" + IsHex.ToString() + "IsOct:" + IsOct.ToString())
#End If


            For pos = 0 To InputStr.Length - 1

                CurrentChar = Convert.ToChar(InputStr.Substring(pos, 1))
                CurrentCharAsc = Strings.Asc(CurrentChar)

                'collect numbers and one period, ignore whitespaces, stop on other
                If IsDecimal Then

                    If System.Char.IsWhiteSpace(CurrentChar) Then
                        'ignore this char
                    ElseIf CurrentChar = "-" Then
                        IsNegative = True
                    ElseIf System.Char.IsDigit(CurrentChar) Then
                        'collect this char
                        NumericString = NumericString + CurrentChar
                    ElseIf CurrentChar = "." Then
                        'The Val function recognizes only the period (.) as a valid decimal separator
                        If Not PeriodCollected Then
                            NumericString = NumericString + CurrentChar
                            PeriodCollected = True
                        Else
                            'period already collected. exit the loop.
                            pos = InputStr.Length
                        End If
                    ElseIf IsE = False AndAlso (CurrentChar = "E"c OrElse CurrentChar = "e"c) Then
                        IsE = True
                        NumericString &= CurrentChar
                    ElseIf IsE AndAlso CurrentChar = "+" Then
                        'ignore this
                    Else
                        'exit the loop
                        pos = InputStr.Length
                    End If

                ElseIf IsHex Then

                    If System.Char.IsWhiteSpace(CurrentChar) Or CurrentChar = "&" Or CurrentChar = "H" Or CurrentChar = "h" Then
                        'ignore this char
                    ElseIf NumericString.Length = 16 Then
                        'max hex chars is 16. exit the loop.
                        pos = InputStr.Length
                    ElseIf System.Char.IsDigit(CurrentChar) Then
                        'collect this char
                        NumericString = NumericString + CurrentChar
                    ElseIf ((CurrentCharAsc >= Strings.Asc("A")) And (CurrentCharAsc <= Strings.Asc("F"))) Or _
                        ((CurrentCharAsc >= Strings.Asc("a")) And (CurrentCharAsc <= Strings.Asc("f"))) Then
                        'collect this char
                        NumericString = NumericString + CurrentChar
                    Else
                        'exit the loop.
                        pos = InputStr.Length
                    End If

                ElseIf IsOct Then

                    If System.Char.IsWhiteSpace(CurrentChar) Or CurrentChar = "&" Or CurrentChar = "O" Or CurrentChar = "o" Then
                        'ignore this char
                    ElseIf ((CurrentCharAsc >= Strings.Asc("0")) And (CurrentCharAsc <= Strings.Asc("7"))) Then
                        'collect this char
                        NumericString = NumericString + CurrentChar
                    Else
                        'exit the loop
                        pos = InputStr.Length
                    End If

                Else
                    Throw New NotSupportedException("FIXME")
                End If

            Next pos

#If TRACE Then
            Console.WriteLine("TRACE:Conversion.Val:collected string:" + NumericString)
#End If

            'convert the NumericString back to long
            'FIXME:the Val return double but it seems to cast to long. add a test and check that.
            Dim retVal As Double = 0
            If NumericString.Length > 0 Then
                If IsDecimal Then
                    retVal = Convert.ToDouble(NumericString, New CultureInfo("en-US"))
                    If IsNegative Then retVal = (-1) * retVal
                ElseIf IsHex Then
                    NumericString = NumericString.ToUpper
                    Dim NumericStringLength As Integer = NumericString.Length
                    If (NumericStringLength = 4 Or NumericStringLength = 8 Or NumericStringLength >= 16) And NumericString.StartsWith("F") Then
                        'its negative
                        If NumericStringLength = 4 Then retVal = Convert.ToDouble(Convert.ToInt64(NumericString, 16)) - Math.Pow(2, 16)
                        If NumericStringLength = 8 Then retVal = Convert.ToDouble(Convert.ToInt64(NumericString, 16)) - Math.Pow(2, 32)
                        If NumericStringLength >= 16 Then retVal = Convert.ToDouble(Convert.ToInt64(NumericString, 16))
                    Else
                        retVal = Convert.ToDouble(Convert.ToInt64(NumericString, 16))
                    End If

                ElseIf IsOct Then
                    retVal = Convert.ToInt64(NumericString, 8)
                Else
                    'FIXME: what else ?
                End If
            End If
            Return retVal

            'exceptions
            'FIXME:OverflowException - InputStr is too large.
            'FIXME:InvalidCastException - Number is badly formed. 
            'FIXME:ArgumentException - Object type expression not convertible to String.

        End Function
#If NET_2_0 Then
        <CLSCompliant(False)> _
        Public Function Hex(ByVal Number As SByte) As String
            Return Convert.ToString(Number, 16).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Hex(ByVal Number As UShort) As String
            Return Convert.ToString(Number, 16).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Hex(ByVal Number As UInteger) As String
            Return Convert.ToString(Number, 16).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Hex(ByVal Number As ULong) As String
            Return Convert.ToString(CLng(Number), 16).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Oct(ByVal Number As SByte) As String
            Return Convert.ToString(Number, 8).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Oct(ByVal Number As UShort) As String
            Return Convert.ToString(Number, 8).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Oct(ByVal Number As UInteger) As String
            Return Convert.ToString(Number, 8).ToUpper
        End Function
        <CLSCompliant(False)> _
        Public Function Oct(ByVal Number As ULong) As String
            Return Convert.ToString(CLng(Number), 8).ToUpper
        End Function
#End If
    End Module
End Namespace