Re: Variable length string

[Kilgallen@eisner.decus.org.nospam (Larry Kilgallen)]

In article <3B77E4A4.50FFA02B@amsjv.com>, Des Walker <des.walker@amsjv.com> writes:
> Des Walker wrote:
>> 
>> Hi,
>> 
>> I think the Text_Io Get procedure attempts to get as many characters as
>> the length of the supplied string and this can include multiple line
>> feed characters.
>> 
> 
> No, I was wrong here. Rereading the ARM suggests the Get procedure for a
> string
> "Determines the length of the given string and attempts that number of
> Get operations for successive characters of the string (in particular,
> no operation is performed if the string is null)."
> 
> and the Get procedure for a Character
> "After skipping any line terminators and any page terminators, reads the
> next character from the specified input file and returns the value of
> this character in the out parameter Item."

But one should not infer any lack of efficiency in the implementation
due to that description.  Anybody skilled enough to write an Ada compiler
knows how to make Get for a line operate without actual subprogram calls
for each character.  So long as the result is the same from the caller
point of view, semantic equivalence is enough.