309 lines
11 KiB
VB.net
309 lines
11 KiB
VB.net
|
''' <summary>
|
||
|
|
''' Used to convert strings into various types.
|
||
|
|
''' </summary>
|
||
|
|
Public Class ScriptConversion
|
||
|
|
|
||
|
|
Enum Associativity
|
||
|
|
Right
|
||
|
|
Left
|
||
|
|
End Enum
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Converts an expression into a <see cref="Double"/>.
|
||
|
|
''' </summary>
|
||
|
|
Public Shared Function ToDouble(ByVal expression As Object) As Double
|
||
|
|
Dim input As String = expression.ToString()
|
||
|
|
Dim retError As Boolean = False
|
||
|
|
Dim retDbl As Double = 0D
|
||
|
|
|
||
|
|
retDbl = InternalToDouble(input, retError)
|
||
|
|
|
||
|
|
If retError = False Then
|
||
|
|
Return retDbl
|
||
|
|
Else
|
||
|
|
If IsArithmeticExpression(expression) = True Then
|
||
|
|
Dim postFix As String = ToPostfix(expression.ToString())
|
||
|
|
|
||
|
|
Return EvaluatePostfix(postFix)
|
||
|
|
Else
|
||
|
|
Return 0D
|
||
|
|
End If
|
||
|
|
End If
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' If the input can be evaluated into a number.
|
||
|
|
''' </summary>
|
||
|
|
Public Shared Function IsArithmeticExpression(ByVal expression As Object) As Boolean
|
||
|
|
Dim retError As Boolean = False
|
||
|
|
Dim postfix As String = ToPostfix(expression.ToString(), retError)
|
||
|
|
If retError = False Then
|
||
|
|
EvaluatePostfix(postfix, retError)
|
||
|
|
Return retError = False
|
||
|
|
Else
|
||
|
|
Return False
|
||
|
|
End If
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
''' Evaluates a math expression in the postfix notation. Example: "2 3 +".
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="input">The postfix string.</param>
|
||
|
|
Private Shared Function EvaluatePostfix(ByVal input As String, Optional ByRef hasError As Boolean = False) As Double
|
||
|
|
Dim stack As New List(Of Double)
|
||
|
|
Dim tokens As List(Of Char) = input.ToCharArray().ToList()
|
||
|
|
|
||
|
|
Dim cNumber As String = ""
|
||
|
|
|
||
|
|
While tokens.Count > 0
|
||
|
|
Dim token As Char = tokens(0)
|
||
|
|
tokens.RemoveAt(0)
|
||
|
|
|
||
|
|
If IsNumber(token) = True Then
|
||
|
|
cNumber &= token.ToString()
|
||
|
|
ElseIf cNumber.Length > 0 Then
|
||
|
|
stack.Insert(0, InternalToDouble(cNumber))
|
||
|
|
cNumber = ""
|
||
|
|
End If
|
||
|
|
|
||
|
|
If cNumber.Length > 0 And tokens.Count = 0 Then
|
||
|
|
stack.Insert(0, InternalToDouble(cNumber))
|
||
|
|
cNumber = ""
|
||
|
|
End If
|
||
|
|
|
||
|
|
If IsOperator(token) = True Then
|
||
|
|
If stack.Count >= 2 Then
|
||
|
|
Dim v2 As Double = stack(0)
|
||
|
|
Dim v1 As Double = stack(1)
|
||
|
|
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
|
||
|
|
Dim result As Double = 0
|
||
|
|
|
||
|
|
Select Case token.ToString()
|
||
|
|
Case "+"
|
||
|
|
result = v1 + v2
|
||
|
|
Case "-"
|
||
|
|
result = v1 - v2
|
||
|
|
Case "*"
|
||
|
|
result = v1 * v2
|
||
|
|
Case "/"
|
||
|
|
If v2 = 0 Then
|
||
|
|
Logger.Log(Logger.LogTypes.Warning, "Script.vb: Cannot evaluate """ & input.ToString() & """ as an arithmetic expression.")
|
||
|
|
hasError = True
|
||
|
|
Return 0
|
||
|
|
Else
|
||
|
|
result = v1 / v2
|
||
|
|
End If
|
||
|
|
Case "^"
|
||
|
|
result = v1 ^ v2
|
||
|
|
Case "%"
|
||
|
|
result = v1 Mod v2
|
||
|
|
End Select
|
||
|
|
|
||
|
|
stack.Insert(0, result)
|
||
|
|
Else
|
||
|
|
Logger.Log(Logger.LogTypes.Warning, "Script.vb: Cannot evaluate """ & input.ToString() & """ as an arithmetic expression.")
|
||
|
|
hasError = True
|
||
|
|
Return 0
|
||
|
|
End If
|
||
|
|
End If
|
||
|
|
End While
|
||
|
|
|
||
|
|
If stack.Count = 1 Then
|
||
|
|
Return stack(0)
|
||
|
|
Else
|
||
|
|
Logger.Log(Logger.LogTypes.Warning, "Script.vb: Cannot evaluate """ & input.ToString() & """ as an arithmetic expression.")
|
||
|
|
hasError = True
|
||
|
|
Return 0
|
||
|
|
End If
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Converts an infix notation to postfix notation.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="input">The infix notation. Example: "2+3".</param>
|
||
|
|
Private Shared Function ToPostfix(ByVal input As String, Optional ByRef hasError As Boolean = False) As String
|
||
|
|
If input.Trim().StartsWith("-") Then
|
||
|
|
input = "0" & input
|
||
|
|
End If
|
||
|
|
|
||
|
|
Dim tokens As List(Of Char) = input.ToCharArray().ToList()
|
||
|
|
Dim stack As New List(Of Char)
|
||
|
|
|
||
|
|
Dim output As String = ""
|
||
|
|
Dim cNumber As String = ""
|
||
|
|
|
||
|
|
While tokens.Count > 0
|
||
|
|
Dim token As Char = tokens(0)
|
||
|
|
tokens.RemoveAt(0)
|
||
|
|
|
||
|
|
' Token is a number:
|
||
|
|
If IsNumber(token) = True Then
|
||
|
|
cNumber &= token.ToString()
|
||
|
|
ElseIf cNumber.Length > 0 Then
|
||
|
|
output &= cNumber.ToString() & " " ' Add to the output.
|
||
|
|
cNumber = ""
|
||
|
|
End If
|
||
|
|
|
||
|
|
If cNumber.Length > 0 And tokens.Count = 0 Then
|
||
|
|
output &= cNumber.ToString() & " "
|
||
|
|
cNumber = ""
|
||
|
|
End If
|
||
|
|
|
||
|
|
' Token is an operator:
|
||
|
|
If IsOperator(token) = True Then
|
||
|
|
Dim o1 As Char = token
|
||
|
|
|
||
|
|
While stack.Count > 0 AndAlso IsOperator(stack(0)) = True AndAlso ((GetAssociativity(o1) = Associativity.Left And GetPrecedence(o1) <= GetPrecedence(stack(0))) Or (GetAssociativity(o1) = Associativity.Right And GetPrecedence(o1) < GetPrecedence(stack(0))))
|
||
|
|
output &= stack(0).ToString() & " "
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
End While
|
||
|
|
|
||
|
|
stack.Insert(0, o1)
|
||
|
|
End If
|
||
|
|
' Token is a left parenthesis:
|
||
|
|
If token = "("c Then
|
||
|
|
stack.Insert(0, token)
|
||
|
|
End If
|
||
|
|
' Token is a right parenthesis:
|
||
|
|
If token = ")"c Then
|
||
|
|
If stack.Count > 0 Then
|
||
|
|
While stack.Count > 0
|
||
|
|
If stack(0) = "("c Then
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
Exit While
|
||
|
|
Else
|
||
|
|
output &= stack(0).ToString() & " "
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
End If
|
||
|
|
End While
|
||
|
|
Else
|
||
|
|
Logger.Log(Logger.LogTypes.Warning, "Script.vb: Cannot convert """ & input.ToString() & """ to an arithmetic expression.")
|
||
|
|
hasError = True
|
||
|
|
Return "0"
|
||
|
|
End If
|
||
|
|
End If
|
||
|
|
End While
|
||
|
|
|
||
|
|
While stack.Count > 0
|
||
|
|
If stack(0) = "("c Or stack(0) = ")"c Then
|
||
|
|
Logger.Log(Logger.LogTypes.Warning, "Script.vb: Cannot convert """ & input.ToString() & """ to an arithmetic expression.")
|
||
|
|
hasError = True
|
||
|
|
Return "0"
|
||
|
|
Else
|
||
|
|
output &= stack(0).ToString() & " "
|
||
|
|
stack.RemoveAt(0)
|
||
|
|
End If
|
||
|
|
End While
|
||
|
|
|
||
|
|
Return output
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' If the token is a number or part of one.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="token">The token.</param>
|
||
|
|
Private Shared Function IsNumber(ByVal token As Char) As Boolean
|
||
|
|
Return "0123456789.,".ToCharArray().Contains(token)
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' If the token is an operator.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="token">The token.</param>
|
||
|
|
Private Shared Function IsOperator(ByVal token As Char) As Boolean
|
||
|
|
Return "+-*/^%".ToCharArray().Contains(token)
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Returns the precedence for an operator.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="[Operator]">The operator.</param>
|
||
|
|
Private Shared Function GetPrecedence(ByVal [Operator] As Char) As Integer
|
||
|
|
Select Case [Operator]
|
||
|
|
Case "+"c, "-"c
|
||
|
|
Return 2
|
||
|
|
Case "*"c, "/"c, "%"c
|
||
|
|
Return 3
|
||
|
|
Case "^"c
|
||
|
|
Return 4
|
||
|
|
End Select
|
||
|
|
|
||
|
|
Return -1
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Returns if an operator has a Left or Right Associativity.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="[Operator]">The operator</param>
|
||
|
|
Private Shared Function GetAssociativity(ByVal [Operator] As Char) As Associativity
|
||
|
|
Select Case [Operator]
|
||
|
|
Case "^"c
|
||
|
|
Return Associativity.Right
|
||
|
|
Case Else
|
||
|
|
Return Associativity.Left
|
||
|
|
End Select
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Tries to convert a single number into a <see cref="Double"/>.
|
||
|
|
''' </summary>
|
||
|
|
Private Shared Function InternalToDouble(ByVal expression As String, Optional ByRef hasError As Boolean = False) As Double
|
||
|
|
expression = expression.Replace(".", My.Application.Culture.NumberFormat.NumberDecimalSeparator)
|
||
|
|
|
||
|
|
If StringHelper.IsNumeric(expression) Then
|
||
|
|
Return System.Convert.ToDouble(expression)
|
||
|
|
Else
|
||
|
|
If expression.ToLower() = "false" Then
|
||
|
|
Return 0
|
||
|
|
ElseIf expression.ToLower() = "true" Then
|
||
|
|
Return 1
|
||
|
|
Else
|
||
|
|
hasError = True
|
||
|
|
Return 0
|
||
|
|
End If
|
||
|
|
End If
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Converts an expression into an <see cref="Integer"/>.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="expression">The expression to convert.</param>
|
||
|
|
Public Shared Function ToInteger(ByVal expression As Object) As Integer
|
||
|
|
Return CInt(Math.Round(ToDouble(expression)))
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Converts an expression to a <see cref="Single"/>.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="expression">The expression to convert.</param>
|
||
|
|
Public Shared Function ToSingle(ByVal expression As Object) As Single
|
||
|
|
Return CSng(ToDouble(expression))
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Converts an expression into a <see cref="Boolean"/>.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="expression">The expression to convert.</param>
|
||
|
|
Public Shared Function ToBoolean(ByVal expression As Object) As Boolean
|
||
|
|
Select Case expression.ToString().ToLower()
|
||
|
|
Case "true", "1"
|
||
|
|
Return True
|
||
|
|
Case Else
|
||
|
|
Return False
|
||
|
|
End Select
|
||
|
|
End Function
|
||
|
|
|
||
|
|
''' <summary>
|
||
|
|
''' Performs a check if an expression is a valid <see cref="Boolean"/>.
|
||
|
|
''' </summary>
|
||
|
|
''' <param name="expression">The expression to perform the check on.</param>
|
||
|
|
Public Shared Function IsBoolean(ByVal expression As Object) As Boolean
|
||
|
|
Dim s As String = expression.ToString()
|
||
|
|
Dim validBools() As String = {"0", "1", "true", "false"}
|
||
|
|
Return validBools.Contains(s.ToLower())
|
||
|
|
End Function
|
||
|
|
|
||
|
|
End Class
|