input can not contain or be of the type of:
Complex floating, structure, Double-precision complex, Pointer, Object
reference, Unsigned Integer, Unsigned Longword Integer, 64-bit
Integer, Unsigned 64-bit Integer
If keywdvalue is an array, it will be convert in a vector.
Beware, this function has loops, ifs ad cases everywhere. So it can
not be used by big keywords (with a lot of elements which are big
arrays).