Re: Newbie question on Ada TExt_IO

["Justin Birtwell" <jbirtwell@yahoo.com>]

Steve,

<<, I would read the value
into a string using something like Text_Io.Read_Line with the string
ridiculously large (maybe 1..256). >>
I couldn't find the package Text_IO.Read_Line did you mean Get_Line?

What 's the difference between having a huge array like String(1..256) and
using an Unbounded_String?  Is it because we need the type to be
specifically String and not Unbounded_String?  Couldn't we convert from one
to the other?

<< If after reading the string the value of
"last" is the size of the string, I know something is wrong and report an
error (unlikely to happen, but handled).  Once I get a reasonably sized
string, I trim leading and trailing spaces using Ada.Fixed.Trim.  >>

How do you evaluate the length of the string using "Input'Last" isn't always
going to be 256, it was for me?

<<Then I check for valid characters using something like
Ada.Strings.Fixed.Index to
make sure the numeric input contains only digits.  Then I use the
Integer'Value to get the actual value of the numeric string.  Just to be
safe the Integer'Value conversion is protected by an exception handler.>>

The Index function has a pattern matching parameter, how do you express "all
digits" without having to specify them individually?

Thanks for your help,
Justin