Re: Case Sensitivity

[John English <je@bton.ac.uk>]

Cameron McShane wrote:
> We need a menu that needs to be case-'in'sensitive. I am using an enumerated
> data type for the 3 menu options ie:
> 
>     type Menu_Options is (buy, read, done)
> 
> If the user is to be allowed to enter Buy or BUY or bUy - etc, do I need to
> make the data type
> 
>     type Menu_Options is (buy, Buy, bUY, etc
> 
> or is there a way of converting user input to all lower case?

If you instantiate Ada.Text_IO.Enumeration_IO for your Menu_Options
type, the user will be able to enter any of the three names in any
case mixture and you will get back the corresponding Menu_Options
result. You will also be able to display the three values using
Put -- the default is all uppercase but you can also select output
in all lowercase. Enumeration_IO for input lets you forget about
case differences completely.

In other words, rather than reading a string, read a Menu_Options
value directly. If the user types anything other than one of your
three possible values, you'll get a Constraint_Error, so checking
for invalid input is simpler too.

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