To use the functions exported from the FormulaParserLib.dll you must declare the functions.
You may do it in this way:
Declare Function FormulaParserLib_SetFormula Lib "FormulaParserLib.dll" (ByVal formula$) As Long
Declare Function FormulaParserLib_IsValid Lib "FormulaParserLib.dll" (ByVal formula$) As Long
Declare Function FormulaParserLib_Parse Lib "FormulaParserLib.dll" () As Long
Declare Function FormulaParserLib_GetStatementNumber Lib "FormulaParserLib.dll" (ByRef num As Long) As Long
Declare Function FormulaParserLib_GetStatement Lib "FormulaParserLib.dll" _
(ByVal num As Long, ByVal arg1$, ByVal arg2$, ByVal oper$, ByVal funct$, ByVal res$) As Long
Then, after the declaration you may use the functions.
For example:
Private Sub butParse_Click()
If (FormulaParserLib_SetFormula("a+b+c-d) <> 1) Then
MsgBox "Error during SetFormula", , "Error"
Exit Sub
End If
If (FormulaParserLib_IsValid("") <> 1) Then
MsgBox "Error during Validate", , "Error"
Exit Sub
End If
If (FormulaParserLib_Parse <> 1) Then
MsgBox "Error during Parse", , "Error"
Exit Sub
End If
Dim arg1$, arg2$, oper$, funct$, res$, num&, i&
'Dim arg1 As String*1000,arg2 As String*1000,oper As String*1000,funct As String*1000,res As String*1000,num&,i&
If (FormulaParserLib_GetStatementNumber(num) <> 1) Then
MsgBox "Error during GetStatementNumber", , "Error"
Exit Sub
End If
Dim out_str$
out_str = ""
For i = 0 To num - 1
arg1 = Space(1000)
arg2 = Space(1000)
oper = Space(1000)
funct = Space(1000)
res = Space(1000)
If (FormulaParserLib_GetStatement(i, arg1, arg2, oper, funct, res) <> 1) Then
MsgBox "Error during GetStatement", , "Error"
Exit Sub
End If
arg1 = Left(arg1, Len(RTrim(arg1)) - 1)
arg2 = Left(arg2, Len(RTrim(arg2)) - 1)
oper = Left(oper, Len(RTrim(oper)) - 1)
funct = Left(funct, Len(RTrim(funct)) - 1)
res = Left(res, Len(RTrim(res)) - 1)
If (Len(oper) > 0 And Len(arg1) > 0 And Len(arg2) > 0 And Len(res) > 0) Then
out_str = out_str + res + "=" + arg1 + oper + arg2 + Chr(10) + Chr(13)
ElseIf (Len(funct) > 0 And Len(arg1) > 0 And Len(res) > 0) Then
out_str = out_str + res + "=" + funct + "(" + arg1 + ")" + Chr(10) + Chr(13)
ElseIf (Len(arg1) > 0 And Len(res) > 0) Then
out_str = out_str + res + "=" + arg1 + Chr(10) + Chr(13)
Else
MsgBox "Error in received statement", , "Error"
Exit Sub
End If
Next
MsgBox out_str
End Sub