Does Excel have a built in method for parsing formulas? (ie: to obtain a list of included RANGE references)

Question

For a given Excel formula in a cell, I\'d like to be able to parse the formula in order to get a list of Excel Range references contained within the formula.

For exa

Answer 1

Tbone, One other option that is not directly what you asked for but could work as alternative solution.

Rather than using a formula to try and find the corrosponding label, Try adjusting your formulas to work for you. Here are a couple of options depending on what the formula you were trying to parse is. 1. If your formula is a lookup you could just offset to look to the left. 2. Alternatively you could use the "Indirect" function in both formulas to ensure they are referencing the correct location.

Answer 2

Thanks to @TimWilliams and @brettdj for pointing me in the right direction to previous discussions on this topic, I can confidently say:

NO, EXCEL DOES NOT HAVE A METHOD FOR PARSING.

However, for my fairly minimal purposes, I've come up with something that works, works with cross worksheet references, and can be called from a UDF.

However, it is extremely brittle, and there are multitudes of perfectly legitimate formulas that I'm certain it wouldn't handle properly.

The code is a mess and could be greatly improved but I just wanted to throw it up on here as I'm moving onto to something else for the time being....

EDIT

Also found this, which looks very interesting:
http://www.dailydoseofexcel.com/archives/2009/12/05/formula-tokenizer/

Public Function CellPrecedents(cell As Range) As Variant()
    Dim resultRanges As New Collection
    If cell.Cells.count <> 1 Then GoTo exit_CellPrecedents
    If cell.HasFormula = False Then GoTo exit_CellPrecedents

    Dim formula As String
    formula = Mid(cell.formula, 2, Len(cell.formula) - 1)

    If IsRange(formula) Then
        resultRanges.Add Range(formula), 1
    Else
        Dim elements() As String
        'Debug.Print formula & " --> "
        formula = Replace(formula, "(", "")
        formula = Replace(formula, ")", "")
        'Debug.Print formula & " --> "
        elements() = SplitMultiDelims(formula, "+-*/\^")
        Dim n As Long, count As Integer
        For n = LBound(elements) To UBound(elements)
            If IsRange(elements(n)) Then
                'ACTUALLY JUST DO A REDIM PRESERVE HERE!!!!
                count = count + 1
                'resultRanges.Add Range(Trim(elements(n)))  '<---  Do **NOT** store as a range, as that gets automatically Eval()'d
                resultRanges.Add Trim(elements(n))
            End If
        Next
    End If

    Dim resultRangeArray() As Variant
    ReDim resultRangeArray(resultRanges.count)
    Dim i As Integer
    For i = 1 To resultRanges.count
        resultRangeArray(i) = CStr(resultRanges(i))  '// have to store as a string so Eval() doesn't get invoked (I think??)
    Next

    CellPrecedents = resultRangeArray

exit_CellPrecedents:
    Exit Function
End Function

Public Function IsRange(var As Variant) As Boolean
    On Error Resume Next
    Dim rng As Range: Set rng = Range(var)
    If err.Number = 0 Then IsRange = True
End Function

(just google SplitMultiDelims for that function)

Answer 3

In short, I think you want to do subpart of : Use VBA to generate code to reproduce basic calculations on an Excel worksheet, and using a function to return n'th DirectPrecedents collection element address or name.

source: http://www.vb-helper.com/howto_vba_excel_formulas.html

This use case however has been deprecated. As of Excel 2007 tables allow a much better solution.