vb写的一个小解释器 功能还很弱很弱，有兴趣的一起完善啊

'------------------------------------------------' ' Author : sysdzw ' ' E-mail : sysdzw@163.com ' ' Bolg : http://hi.baidu.com/sysdzw ' ' QQ : 171977759 ' ' Date : 2010-4-6 ' '------------------------------------------------' Option Explicit Dim reg As Object Dim matchs As Object,match As Object Dim reg2 As Object Dim matchs2 As Object,match2 As Object Dim regForTest As Object Dim dic As Object Dim sc As Object Dim strSource$,vSource,i% Dim rVar$,rValuePattern$,rVarKeyWord$,rString$,rNumber$,rLoop$ Dim lngCurrentLine As Integer 'the code line's type Private Enum ECodeType eCTSetValue eCTOutPut eCTOutPutEx eCTIF eCTELSE eCTEND eCTFOR eCTGOTO eCTGOTOLine eCTUnknow End Enum 'the variable's type Private Enum EVariableType eVTString eVTNumber eVTBool eVTDate eVTTime End Enum Private Sub Form_Load() Set sc = CreateObject("ScriptControl") sc.Language = "VBScript" Set reg = CreateObject("vbscript.regexp") reg.Global = True reg.IgnoreCase = True Set reg2 = CreateObject("vbscript.regexp") reg2.Global = True reg2.IgnoreCase = True Set regForTest = CreateObject("vbscript.regexp") regForTest.Global = True regForTest.IgnoreCase = True Set dic = CreateObject("Scripting.Dictionary") rVar = "[a-zA-Z_/u4e00-/u9fa5][/da-zA-Z_/u4e00-/u9fa5]*?" rString = """[/s/S]*?""" rNumber = "/d+/.?/d*" rValuePattern = "(" & rNumber & "|" & rString & "|" & rVar & ")" rLoop = "[a-zA-z/Z_]+?/d*" rVarKeyWord = "(puts|print|printf)" End Sub Private Sub Command1_Click() Dim strLineCode$ Dim strVarName$,strVarValue$ Dim sBefore$,sAfter$ Dim intCodeLineType As Integer Dim strCondition As String Dim blnCondition As Boolean If txtOutput.Text <> "" And Right(txtOutput.Text,2) <> vbCrLf Then txtOutput.Text = txtOutput.Text & vbCrLf txtOutput.SelStart = Len(txtOutput.Text) txtOutput.SelText = ">Start run program" & vbCrLf strSource = txtSource.Text vSource = Split(strSource,vbCrLf) dic.removeall lngCurrentLine = 0 Do strLineCode = Trim(vSource(lngCurrentLine)) If strLineCode <> "" Then intCodeLineType = getType(strLineCode) Select Case intCodeLineType Case eCTSetValue reg.Pattern = "^(" & rVar & ")/s*?/=(.*)$" Set matchs = reg.Execute(strLineCode) sBefore = matchs(0).SubMatches(0) sAfter = matchs(0).SubMatches(1) If regTest(sAfter,"^" & rNumber & "$") Then dic(sBefore) = eVTNumber & sAfter ElseIf regTest(sAfter,"^" & rString & "$") Then dic(sBefore) = eVTString & Mid(sAfter,2,Len(sAfter) - 2) ElseIf regTest(sAfter,"^" & rVar & "$") Then If Not dic.Exists(sAfter) Then dic(sAfter) = eVTString dic(sBefore) = eVTString Else dic(sBefore) = dic(sAfter) End If Else 'is a expression dic(sBefore) = getExpressionResult(sAfter) End If Case eCTOutPut reg.Pattern = "^" & rVarKeyWord & "/s+?" & rValuePattern & "$" Set matchs = reg.Execute(strLineCode) txtOutput.SelText = getTrueValue(matchs(0).SubMatches(1)) & vbCrLf Case eCTOutPutEx reg.Pattern = "^" & rVarKeyWord & "/s+?(.*?)$" Set matchs = reg.Execute(strLineCode) txtOutput.SelText = Mid(getExpressionResult(matchs(0).SubMatches(1)),2) & vbCrLf Case eCTIF reg.Pattern = "^/s*?if(.+)$" Set matchs = reg.Execute(strLineCode) strCondition = matchs(0).SubMatches(0) reg.Pattern = "^/s*?" & rValuePattern & "/s*?(<>|>/=|</=|/=|>|<)/s*?" & rValuePattern & "/s*?$" Set matchs = reg.Execute(strCondition) sBefore = getTrueValue(matchs(0).SubMatches(0)) sAfter = getTrueValue(matchs(0).SubMatches(2)) If Left(sBefore,1) = eVTNumber Or Left(sAfter,1) = eVTNumber Then sBefore = Mid(sBefore,2) sAfter = Mid(sAfter,2) Select Case matchs(0).SubMatches(1) Case "<>": blnCondition = (Val(sBefore) <> Val(sAfter)) Case ">=": blnCondition = (Val(sBefore) >= Val(sAfter)) Case "<=": blnCondition = (Val(sBefore) <= Val(sAfter)) Case ">": blnCondition = (Val(sBefore) > Val(sAfter)) Case "<": blnCondition = (Val(sBefore) < Val(sAfter)) Case "=": blnCondition = (Val(sBefore) = Val(sAfter)) End Select Else Select Case matchs(0).SubMatches(1) Case "<>": blnCondition = (sBefore <> sAfter) Case ">=": blnCondition = (sBefore >= sAfter) Case "<=": blnCondition = (sBefore <= sAfter) Case ">": blnCondition = (sBefore > sAfter) Case "<": blnCondition = (sBefore < sAfter) Case "=": blnCondition = (sBefore = sAfter) End Select End If If Not blnCondition Then lngCurrentLine = getTheElseLine(lngCurrentLine) End If Case eCTELSE lngCurrentLine = getTheElseLine(lngCurrentLine,"end") Case eCTGOTO reg.Pattern = "^/s*?goto/s*?(" & rLoop & ")/s*$" Set matchs = reg.Execute(strLineCode) lngCurrentLine = getTheGotoLine(matchs(0).SubMatches(0) & ":") Case eCTFOR Case eCTUnknow txtOutput.SelText = "Error at Line " & lngCurrentLine + 1 & ": """ & strLineCode & """" & vbCrLf txtOutput.SelText = ">Exit code: -1" & vbCrLf Exit Sub End Select End If lngCurrentLine = lngCurrentLine + 1 If lngCurrentLine > UBound(vSource) Then Exit Do Loop txtOutput.SelText = ">Exit code: 0" & vbCrLf End Sub 'get the line code's type Private Function getType(ByVal strLineCode$) As ECodeType Dim vTmp If regTest(strLineCode,"^" & rVar & "/s*?/=/s*?.*$") Then getType = eCTSetValue Exit Function End If If regTest(strLineCode,"^/s*?if/s*?.*$") Then getType = eCTIF Exit Function End If If regTest(strLineCode,"^/s*?for/s*?.*$") Then getType = eCTFOR Exit Function End If If regTest(strLineCode,"^/s*?else/s*?.*$") Then getType = eCTELSE Exit Function End If If regTest(strLineCode,"^/s*?end/s*?.*$") Then getType = eCTEND Exit Function End If If regTest(strLineCode,"^/s*?goto/s*?.*$") Then getType = eCTGOTO Exit Function End If If regTest(strLineCode,"^/s*?" & rLoop & "/:/s*$") Then getType = eCTGOTOLine Exit Function End If If regTest(strLineCode,"^" & rVarKeyWord & "/s+?.+?$") Then If regTest(strLineCode & " + ","^" & rVarKeyWord & "/s+?" & "(.+?)/s+?/+/s+?") Then getType = eCTOutPutEx Exit Function End If If regTest(strLineCode,"^" & rVarKeyWord & "/s+?" & rValuePattern & "$") Then getType = eCTOutPut End If getType = eCTOutPut Exit Function End If getType = eCTUnknow End Function 'the para has 3 kinds '1.num 2.string 3.var Private Function getTrueValue(sValue$) As String If regTest(sValue,"^" & rNumber & "$") Then getTrueValue = eVTNumber & sValue ElseIf regTest(sValue,"^" & rString & "$") Then getTrueValue = eVTString & Mid(sValue,Len(sValue) - 2) ElseIf regTest(sValue,"^" & rVar & "$") Then If Not dic.Exists(sValue) Then dic(sValue) = eVTString getTrueValue = eVTString Else getTrueValue = dic(sValue) End If End If End Function 'the agrs is a expression Private Function getExpressionResult(strExp As String) As String Dim strTmp$,i%,isNumExp As Boolean Dim strResult$,strTrueExp$,strExpTmp$ strTmp = Replace(strExp,"(","") strTmp = Replace(strTmp,")","") reg.Pattern = "(.+?)/s*?[/+/-/*/]/s*?" Set matchs = reg.Execute(strTmp & "+") reg2.Pattern = "(.+?)/s*?[/+/-/*/]/s*?" Set matchs2 = reg2.Execute(strExp & "+") isNumExp = True For i = 0 To matchs.Count - 1 strExpTmp = Trim(matchs(i).SubMatches(0)) If regTest(strExpTmp,"^" & rNumber & "$") Then strTrueExp = strTrueExp & matchs2(i) ElseIf regTest(strExpTmp,"^" & rString & "$") Then strTrueExp = strTrueExp & matchs2(i) isNumExp = False ElseIf regTest(strExpTmp,"^" & rVar & "$") Then If Not dic.Exists(strExpTmp) Then dic(strExpTmp) = eVTString Else If Left(dic(strExpTmp),1) <> eVTNumber Then isNumExp = False strTrueExp = strTrueExp & Replace(matchs2(i),strExpTmp,Mid(dic(strExpTmp),2)) End If End If Next If isNumExp Then If Right(strTrueExp,1) = "+" Then strTrueExp = Left(strTrueExp,Len(strTrueExp) - 1) getExpressionResult = eVTNumber & WZcalc(strTrueExp) Else reg.Pattern = "(.+?)/s*?/+/s*?" Set matchs = reg.Execute(strExp & "+") For i = 0 To matchs.Count - 1 strExpTmp = Trim(matchs(i).SubMatches(0)) If regTest(strExpTmp,"^" & rNumber & "$") Then strResult = strResult & strExpTmp ElseIf regTest(strExpTmp,"^" & rString & "$") Then strResult = strResult & Mid(strExpTmp,Len(strExpTmp) - 2) ElseIf regTest(strExpTmp,"^" & rVar & "$") Then If Not dic.Exists(strExpTmp) Then dic(strExpTmp) = eVTString Else strResult = strResult & Mid(dic(strExpTmp),2) End If End If Next getExpressionResult = eVTString & strResult End If End Function 'get the "else" line,if it hadn't "else" it'll return the "end" line. 'if the para "strKey" is "end",this means it'll find the "end" line. Private Function getTheElseLine(intCurIfLine As Integer,Optional strKey = "else") As Integer Dim v,i% Dim isIFClosed() As Boolean Dim intCurrentIF As Integer v = Split(txtSource.Text,vbCrLf) i = intCurIfLine + 1 intCurrentIF = 0 ReDim Preserve isIFClosed(intCurrentIF) isIFClosed(intCurrentIF) = False Do If regTest(v(i),"^/s*?if/s*?.*$") Then ReDim Preserve isIFClosed(UBound(isIFClosed) + 1) intCurrentIF = UBound(isIFClosed) isIFClosed(intCurrentIF) = False ElseIf regTest(v(i),"^/s*?else/s*$") Then If intCurrentIF = 0 Then getTheElseLine = i If strKey = "else" Then Exit Function End If ElseIf regTest(v(i),"^/s*?end/s*$") Then If intCurrentIF = 0 Then getTheElseLine = i Exit Function Else isIFClosed(intCurrentIF) = True Do intCurrentIF = intCurrentIF - 1 If isIFClosed(intCurrentIF) = False Then Exit Do Loop End If End If i = i + 1 If i > UBound(v) Then Exit Do Loop End Function 'get the "goto" line Private Function getTheGotoLine(strGotoTag As String) As Integer Dim v,i% Dim intLen As Integer intLen = Len(strGotoTag) v = Split(txtSource.Text,vbCrLf) For i = 0 To UBound(v) If Left(v(i),intLen) = strGotoTag Then getTheGotoLine = i Exit Function End If Next End Function 'test the string is mathed the pattern Private Function regTest(ByVal sData$,sPattern$) As Boolean regForTest.Pattern = sPattern regTest = regForTest.Test(sData) End Function Public Function WZcalc(Tmpstr$) As Double WZcalc = sc.Eval(Tmpstr) End Function Private Sub Form_Resize() If Me.WindowState = 1 Then Exit Sub txtSource.Height = (Me.ScaleHeight - txtSource.Top) * 0.65 txtSource.Width = Me.ScaleWidth - 45 Label1.Top = txtSource.Top + txtSource.Height + 45 txtOutput.Move 0,Label1.Top + Label1.Height + 45,Me.ScaleWidth - 45,Me.ScaleHeight - Label1.Top - Label1.Height - 90 End Sub Private Sub txtSource_GotFocus() Dim C As Object On Error Resume Next For Each C In Me.Controls C.TabStop = False Next End Sub Private Sub txtSource_LostFocus() Dim C As Object On Error Resume Next For Each C In Me.Controls C.TabStop = True Next End Sub Private Sub Command2_Click() MsgBox getTheElseLine(1) End Sub Private Sub Command3_Click() Dim v,t$ Dim isIFClosed() As Boolean Dim intCurrentIF As Integer v = Split(txtSource.Text,vbCrLf) i = 2 intCurrentIF = 0 ReDim Preserve isIFClosed(intCurrentIF) isIFClosed(intCurrentIF) = False Do If InStr(v(i),"if") > 0 Then ReDim Preserve isIFClosed(UBound(isIFClosed) + 1) intCurrentIF = UBound(isIFClosed) isIFClosed(intCurrentIF) = False ElseIf InStr(v(i),"else") > 0 Then If intCurrentIF = 0 Then MsgBox "else at line: " & i + 1 End If ElseIf InStr(v(i),"end") > 0 Then If intCurrentIF = 0 Then MsgBox "end at line: " & i + 1 Else isIFClosed(intCurrentIF) = True Do intCurrentIF = intCurrentIF - 1 If isIFClosed(intCurrentIF) = False Then Exit Do Loop End If End If i = i + 1 If i > UBound(v) Then Exit Do Loop End Sub

点击左上角的“+ expand source”即可展开代码，需要添加按钮Command1，文本框txtSource和txtOutput

一、交换两个变量的范例

二、if语句嵌套结合goto的范例1

三、if语句嵌套结合goto的范例2

四、多层if嵌套测试

五、99乘法表演示

（编辑：李大同）

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