Hi Michael Bowen,
I see these problems with the new ABNF:
(1)
The new ABNF allows myData[ Gender ].
Derivation for that is:
[ Gender ] matches spaced-lbracket inner-reference spaced-rbracket with Gender as inner-reference.
Gender as inner-reference matches column-range.
Gender as column-range matches simple-column-name.
But Excel considers myData[ Gender ] as invalid. When you enter it, Excel corrects it to myDate[Gender]. When it is in file markup, Excel generates a #Ref! error.
When you allow it in the ABNF, then you need to change Excel.
(2)
The new ABNF allows myData[ [#Headers] ].
Derivation for that is:
myData[ [#Headers] ] matches spaced-lbracket inner-reference spaced-rbracket with [#Headers] as inner-reference.
[#Headers] as inner-reference matches keyword-list.
[#Headers] as keyword-list matches keyword.
But Excel changes myData[ [#Headers] ] to the invalid expression myDate [#Headers] , both when you enter the expression or when it is in file markup.
When you allow myData[ [#Headers] ] in the ABNF, then it is questionable whether Excel should change a valid expression. When you decide to keep the current behavior, Excel needs a fix to produce a valid expression. Excel needs to remove not only the brackets but the spaces as well.
So my question is, whether you really intend that myData[ Gender ] and myData[ [#Headers] ] are valid expressions?