;Stringrechner
Function calc#(r$) ;calc(Rechnungsstring)

;Umformungen + Konstanten
r=Lower(r)
r=Replace(r,"'","^")
r=Replace(r," ","")
r=Replace(r,"pi",3.141592653589)
r=Replace(r,"e",2.718281828459)

;Klammern
While Instr(r,"(") > 0

kla=1
While Mid(r,kla,1)<>"(" Or (Instr(Mid(r,kla+1),"(") < Instr(Mid(r,kla+1),")") And Instr(Mid(r,kla+1),"(") > 0)
kla=kla+1
Wend

klz=Instr(Mid(r,kla+1),")")+kla

If kla = 1 Then
r=calc2(Mid(r,kla+1,klz-1-kla))+Mid(r,klz+1)
ElseIf (Mid(r,kla-1,1)="+" Or Mid(r,kla-1,1)="-" Or Mid(r,kla-1,1)="*" Or Mid(r,kla-1,1)="/" Or Mid(r,kla-1,1)="^" Or Mid(r,kla-1,1)="(") Then
r=Left(r,kla-1)+calc2(Mid(r,kla+1,klz-1-kla))+Mid(r,klz+1)
Else

fna = kla-1
While Mid(r,fna,1) <> "+" And Mid(r,fna,1) <> "-" And Mid(r,fna,1) <> "*" And Mid(r,fna,1) <> "/" And Mid(r,fna,1) <> "^" And Mid(r,fna,1) <> "(" And Mid(r,fna,1) <> ","
fna = fna-1
If fna = 0 Then Exit
Wend

;Funktionen
If Instr(Mid(r,fna+1,klz-1-fna),",")=0 Then
z1#=calc2(Mid(r,kla+1,klz-1-kla))
Else
z1#=calc2(Mid(r,kla+1,Instr(r,",")-1-kla))
z2#=calc2(Mid(r,Instr(r,",")+1,klz-1-Instr(r,",")))
EndIf

Select Mid(r,fna+1,kla-1-fna)

;1-Variablen-Funktionen
Case "sin" r=Left(r,fna)+Sin(z1)+Mid(r,klz+1)
Case "cos" r=Left(r,fna)+Cos(z1)+Mid(r,klz+1)
Case "tan" r=Left(r,fna)+Tan(z1)+Mid(r,klz+1)
Case "asin" r=Left(r,fna)+ASin(z1)+Mid(r,klz+1)
Case "acos" r=Left(r,fna)+ACos(z1)+Mid(r,klz+1)
Case "atan" r=Left(r,fna)+ATan(z1)+Mid(r,klz+1)
Case "sqr" r=Left(r,fna)+Sqr(z1)+Mid(r,klz+1)
Case "floor" r=Left(r,fna)+Floor(z1)+Mid(r,klz+1)
Case "ceil" r=Left(r,fna)+Ceil(z1)+Mid(r,klz+1)
Case "ln" r=Left(r,fna)+Str(Log(z1))+Mid(r,klz+1)
Case "lg" r=Left(r,fna)+Log(z1)/Log(10)+Mid(r,klz+1)
Case "int" r=Left(r,fna)+Str(Int(z1)+(Float(z1) Mod 1 = 0.5))+Mid(r,klz+1)

;2-Variablen-Funktionen
Case "mod" r=Left(r,fna)+Str(Float(z1) Mod Float(z2))+Mid(r,klz+1)
Case "log" r=Left(r,fna)+Log(z1)/Log(z2)+Mid(r,klz+1)
Case "max" r=Left(r,fna)+Str((z1>=z2)*z1+(z2>z1)*z2)+Mid(r,klz+1)
Case "min" r=Left(r,fna)+Str((z1<=z2)*z1+(z2<z1)*z2)+Mid(r,klz+1)
Case "root" r=Left(r,fna)+Str(z1^(1/z2))+Mid(r,klz+1)

End Select

EndIf
Wend

;Restliche Berechnung
r=calc2(r$)

;Ausgabe
Return Float(r)

End Function


;2. Funktion
Function calc2$(r$)

;Voreinstellungen
Repeat
r=Replace(r,"++","+")
r=Replace(r,"+++","+")
r=Replace(r,"+-","-")
r=Replace(r,"-+","-")
r=Replace(r,"--","+")
r=Replace(r,"---","-")
Until Instr(r,"++")=0 And Instr(r,"--")=0 And Instr(r,"+-")=0 And Instr(r,"-+")=0
If Left(r,1)="+" Then r=Mid(r,2)

;verschiedene Operatoren

;^
While Instr(r,"^")
r=calc3(r,"^")
Wend

;*/
While Instr(r,"*") > 0 Or Instr(r,"/") > 0

While Instr(r,"*-")>0
r$=Left(r,Instr(r,"*-"))+"~"+Mid(r,Instr(r,"*-")+2)
Wend

While Instr(r,"/-")>0
r$=Left(r,Instr(r,"/-"))+"~"+Mid(r,Instr(r,"/-")+2)
Wend

z$="*"
If (Instr(r,"/") < Instr(r,"*") And Instr(r,"/")>0) Or Instr(r,"*") = 0 Then z="/"
r=calc3(r,z)
Wend

;+-
While Instr(r,"+") > 0 Or Instr(Mid(r,2),"-") > 0
If Left(r,1) = "-" Then r="~"+Mid(r,2)

z="+"
If (Instr(r,"-") < Instr(r,"+") And Instr(r,"-")>0) Or Instr(r,"+") = 0 Then z="-"
r=calc3(r,z)
Wend

;Ausgabe
Return r$

End Function


;3.Funktion
Function calc3$(r$,z$)

;Zahlbegrenzungen
op=Instr(r,z)

za=op-1

While Mid(r,za,1) <> "+" And Mid(r,za,1) <> "-" And Mid(r,za,1) <> "*" And Mid(r,za,1) <> "/" And Mid(r,za,1) <> "^"
za=za-1
If za = 0 Then Exit
Wend

ze=op+1
While Mid(r,ze,1) <> "+" And Mid(r,ze,1) <> "-" And Mid(r,ze,1) <> "*" And Mid(r,ze,1) <> "/" And Mid(r,ze,1) <> "^" And ze<=Len(r)
ze=ze+1
Wend

;Minusrückänderung
r=Replace(r,"~","-")

;Verschiedene Operationen
Select z
Case "-" r=Left(r,za)+Str(Float(Mid(r,za+1,op-1))-Float(Mid(r,op+1,ze-1)))+Mid(r,ze)
Case "+" r=Left(r,za)+Str(Float(Mid(r,za+1,op-1))+Float(Mid(r,op+1,ze-1)))+Mid(r,ze)
Case "/" r=Left(r,za)+Str(Float(Mid(r,za+1,op-1))/Float(Mid(r,op+1,ze-1)))+Mid(r,ze)
Case "*" r=Left(r,za)+Str(Float(Mid(r,za+1,op-1))*Float(Mid(r,op+1,ze-1)))+Mid(r,ze)
Case "^" r=Left(r,za)+Str(Float(Mid(r,za+1,op-1))^Float(Mid(r,op+1,ze-1)))+Mid(r,ze)
End Select

Return r$

End Function
;/Stringrechner

Rechnung$="2^3*17.245*log(13)-(17.9+22.11)"

f=WriteFile("c:\tmpFile01")
s$="f=WriteFile("+Chr$(34)+"c:\tmpfile02"+Chr$(34)+")"+Chr$(10)
s$=s$+"Writefloat f,("+Rechnung+")"+Chr$(10)+"CloseFile(f)"+Chr$(10)
WriteLine f,s:CloseFile f : Delay 2000
ExecFile SystemProperty("appdir")+"\blitzcc.exe +q c:\tmpFile01" : Delay 2000
f=ReadFile("c:\tmpfile02") : Loesung#=ReadFloat(f) : CloseFile f
DeleteFile "c:\tmpfile01" : DeleteFile "c:\tmpfile02"

Print Loesung
WaitKey()

("+Rechnung+")"