www.delorie.com/gnu/docs/gcc/gnat_ug_119.html   search  
 
Buy the book!


Untitled Document

[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

10.3.4 String Types

The value of a variable may be restricted to a list of string literals. The restricted list of string literals is given in a string type declaration.

Here is an example of a string type declaration:

 
   type OS is ("NT, "nt", "Unix", "Linux", "other OS");

Variables of a string type are called typed variables; all other variables are called untyped variables. Typed variables are particularly useful in case constructions (see 10.3.8 case Constructions).

A string type declaration starts with the reserved word type, followed by the name of the string type (case-insensitive), followed by the reserved word is, followed by a parenthesized list of one or more string literals separated by commas, followed by a semicolon.

The string literals in the list are case sensitive and must all be different. They may include any graphic characters allowed in Ada, including spaces.

A string type may only be declared at the project level, not inside a package.

A string type may be referenced by its name if it has been declared in the same project file, or by its project name, followed by a dot, followed by the string type name.


  webmaster     delorie software   privacy  
  Copyright 2003   by The Free Software Foundation     Updated Jun 2003