Support for shared formula types

[benburleson]

I noticed one of my formulas was not getting returned through this package, so looked into it and found that GetCellFormula() (https://github.com/360EntSecGroup-Skylar/excelize/blob/master/cell.go#L228) only works for simple formulas, not shared like the example below:

<row r="46" spans="1:4">
   <c r="A46" s="4" t="s">
      <v>13</v>
   </c>
   <c r="B46" t="str">
      <v>1</v>
   </c>
   <c r="C46">
      <f t="shared" si="0" />
      <v>2</v>
   </c>
   <c r="D46" />
</row>

In my example,C46's formula is simply =B46, so it's not really clear to me what si="0" even means.

Are there any plans to support shared formula types?

[xuri]

Thanks for your issue. I have initialized shared formula types support. Note that: currently, this function not validate ref tag to check the cell if or not in allow area, and always return origin shared formula.