Front-ends may lack representation for some of KeyValue's basic
types: number, text, boolean and date. In that case lexical conversions
are required. For instance, LibreOffice Calc and Excel do not have
specific representations for time. Instead, they use a double
which represents the number of days since a certain epoch. Therefore, the
front-end must convert from
double to KeyValue's
representation of time.
Moreover, lexical conversions can make user interface more friendly.
For instance, LibreOffice Calc and Excel users might prefer to use
Yes" and "
No" rather than the built-in boolean
Front-ends must implement all lexical converters they need. The
lexical conversion cited above (from text to boolean values) is, indeed,
implemented for LibreOffice and Excel add-ins. Instead of
FALSE we can use any of the following
Additionally, LibreOffice and Excel add-ins implement lexical
conversions from text to number, that is, providing the text
1.23" when a number is required is the same as providing the