tokenizer.vb

来自「《ViSUAL BASIC》设计模式」· VB 代码 · 共 50 行

Imports System



Public class StringTokenizer

Private s As String
private i As Integer
Private sep As String   'token separator
'------
Public Overloads Sub New(st As String)
 MyBase.New
 s = st         'copy in string
 sep = " "      'default separator
End Sub
'------
Public Overloads Sub New(st as String, sepr as String)
  MyBase.New
  s = st
  sep = sepr
End Sub
'------
Public Sub setSeparator(ByVal sp As String)
  sep = sp      'copy separator
End Sub
'------
Public Function nextToken() As String
Dim tok as String
try
i = s.indexOf(sep)   'look for occurrence of separator

If i > 0 Then       'if found
  tok = s.substring(0, i ).trim            'return string to left
  s = s.substring(i+1).trim  'shorten string   
Else
  tok = s          'otherwise return end of string
  s = ""            'and set remainder to zero length
End If
catch e As Exception
  tok = ""
end try  
return tok
End Function
    Public Function hasMoreElements() As Boolean
        Return s.Length > 0
    End Function
End Class