Re: conversion

[Jeffrey Carter <spam@spam.com>]

Andrew wrote:
> Ok, so I found the ada.strings.unbounded package spec and body and took a
> look
> at the definition and implementation of unbounded string.  Finally I found
> them!
> 
> Unbounded_string is basically an object that contains a reference to a
> string.

What you are discussing is one specific compiler's implementation of 
Ada.Strings.Unbounded.Unbounded_String. Other compilers may use other 
implementations. This may seem unlikely, but some compilers might treat 
objects of this type as a special case in order to speed up the memory 
management required for them.

Ada has so many ways to use type String that there are few cases when a 
variable-length string type is really needed. Many cases where other 
languages need a variable string can be handled very easily by Ada's 
type String, and many uses of Unbounded_String in Ada are more examples 
of laziness or unfamiliarity with Ada's capabilities than of a real need 
for a variable string.

This is similar to the case of pointers. Access types are needed much 
more rarely in Ada than in many other languages, especially C. People 
who are using a lot of access types, objects, and values in Ada are 
probably using the language ineffectively, frequently because that's the 
way they're used to doing things in other languages.

-- 
Jeff Carter
"I'm a lumberjack and I'm OK."
Monty Python's Flying Circus