getColumnIndex static method
Converts A1 notation letter label
into column index
A -> 1
B -> 2
AA -> 27
Implementation
static int getColumnIndex(String label) {
final chars = label.split('');
var res = 0;
for (final char in chars) {
res *= 26;
res += 1 + char.codeUnitAt(0) - _charCodeUnitA;
}
return res;
}