Ada Programming/Ada 2005

2005 __TOC__ This is an overview of the major features that are available in Ada 2005, the version of the Ada standard that was accepted by ISO in January 2007 (to differentiate it from its predecessors Ada 83 and Ada 95, the informal name Ada 2005 is generally agreed on). For the rationale and a more detailed (and very technical) description, see the Amendment to the Ada Reference Manual following the links to the last version of every Ada Issue document (AI). Although the standard is now published, not all compilers will be able to handle it. Many of these additions are already implemented by the following Free Software compilers: GNAT GPL Edition GCC 4.1 GNAT Pro 6.0.2 (the AdaCore supported version) is a complete implementation. After downloading and installing any of them, remember to use the -gnat05 switch when compiling Ada 2005 code. Note that Ada 2005 is the default mode in GNAT GPL 2007 Edition. Language features Character set Not only does Ada 2005 now support a new 32-bit character type — called Wide_Wide_Character — but the source code itself may be of this extended character set as well. Thus Russians and Indians, for example, will be able to use their native language in identifiers and comments. And mathematicians will rejoice: The whole Greek and fractur character sets are available for identifiers. For example, Ada.Numerics will be extended with a new constant: π : constant := Pi; This is not a new idea — GNAT always had the -gnatic compiler option to specify the character set . But now this idea has become standard, so all Ada compilers will need to support Unicode 4.0 for identifiers — as the new standard requires. See also: 285 Support for 16-bit and 32-bit characters 388 Add Greek pi to Ada.Numerics Interfaces Interfaces allow for a limited form of multiple inheritance similar to Java and C#. You find a full description here: Ada Programming/OO. See also: 251 Abstract Interfaces to provide multiple inheritance 345 Protected and task interfaces Union In addition to Ada's safe variant record an unchecked C style union is now available. You can find a full description here: Ada Programming/Types/record#Union. See also: 216 Unchecked unions -- variant records with no run-time discriminant B 3 3 Pragma Unchecked_Union With The with statement got a massive upgrade. First there is the new limited with which allows two packages to with each other. Then there is private with to make a package only visible inside the private part of the specification. See also: 217 Limited With Clauses 6 262 Access to private units in the private part Access types Not null access An access type definition can specify that the access type can never be null. See Ada Programming/Types/access#Null exclusions. See also: 231 Access-to-constant parameters and null-excluding access subtypes Anonymous access The possible uses of anonymous access types are extended. They are allowed virtually in every type or object definition, including access to subprogram parameters. Anonymous access types may point to constant objects as well. Also, they could be declared to be not null. With the addition of the following operations in package Standard, it is possible to test the equality of anonymous access types. function "=" (Left, Right : universal_access) return Boolean; function "/="(Left, Right : universal_access) return Boolean; See Ada Programming/Types/access#Anonymous access. See also: 230 Generalized use of anonymous access types 385 Stand-alone objects of anonymous access types 318 Limited and anonymous access return types 2 Language library Containers A major addition to the language library is the generic packages for containers. If you are familiar with the C++ STL, you will likely feel very much at home using Ada Containers. One thing, though: Ada is a block structured language. Many ideas of how to use the STL employ this feature of the language. For example, local subprograms can be supplied to iteration schemes. The original Ada Issue text 302 Container library 3 has now been transformed into A 18 Containers. If you know how to write Ada programs, and have a need for vectors, lists, sets, or maps (tables), please have a look at the 302 AI Text 3 mentioned above. There is an !example section in the text explaining the use of the containers in some detail. Matthew Heaney provides a number of demonstration programs with his reference implementation of AI-302 (Ada Containers) which you can find at tigris. In Ada Programming/Containers you will find a demo using containers. Historical side note: The C++ STL draws upon the work of David R. Musser and Alexander A. Stepanov. For some of their studies of generic programming, they had been using Ada 83. The Stepanov Papers Collection has a few publications available. Scan Filesystem Directories and Environment Variables See also: 248 Directory Operations 370 Environment variables Numerics Besides the new constant of package Ada.Numerics (see Character Set above), the most important addition are the packages to operate with vectors and matrices. See also: 388 Add Greek pi (π) to Ada.Numerics 296 Vector and matrix operations (Related note on Ada programming tools: AI-388 contains an interesting assessment of how compiler writers are bound to perpetuate the lack of handling of international characters in programming support tools for now. As an author of Ada programs, be aware that your tools provider or Ada consultant could recommend that the program text be 7bit ASCII only.) Real-Time and High Integrity Systems See also: 297 Timing events 307 Execution-Time Clocks 354 Group execution-time budgets 266 Task termination procedure 2 386 Further functions returning Time_Span values Ravenscar profile See also: 249 Ravenscar profile for high-integrity systems 305 New pragma and additional restriction identifiers for real-time systems 347 Title of Annex H 265 Partition Elaboration Policy for High-Integrity Systems New scheduling policies See also: 355 Priority Specific Dispatching including Round Robin 357 Support for Deadlines and Earliest Deadline First Scheduling 298 Non-Preemptive Dispatching Dynamic priorities for protected objects See also: 327 Dynamic ceiling priorities Summary of what's new New keywords Added 3 keywords (72 total) interface overriding synchronized New pragmas Added 11 pragmas: Assert Assertion_Policy Detect_Blocking No_Return Partition_Elaboration_Policy Preelaborable_Initialization Priority_Specific_Dispatching Profile Relative_Deadline Unchecked_Union Unsuppress New attributes Added 7 attributes: Machine_Rounding Mod Priority Stream_Size Wide_Wide_Image Wide_Wide_Value Wide_Wide_Width New packages Assertions: Ada.Assertions Container library: Ada.Containers Ada.Containers.Vectors Ada.Containers.Doubly_Linked_Lists Ada.Containers.Generic_Array_Sort (generic procedure) Ada.Containers.Generic_Constrained_Array_Sort (generic procedure) Ada.Containers.Hashed_Maps Ada.Containers.Ordered_Maps Ada.Containers.Hashed_Sets Ada.Containers.Ordered_Sets Ada.Containers.Indefinite_Vectors Ada.Containers.Indefinite_Doubly_Linked_Lists Ada.Containers.Indefinite_Hashed_Maps Ada.Containers.Indefinite_Ordered_Maps Ada.Containers.Indefinite_Hashed_Sets Ada.Containers.Indefinite_Ordered_Sets Vector and matrix manipulation: Ada.Numerics.Real_Arrays Ada.Numerics.Complex_Arrays Ada.Numerics.Generic_Real_Arrays Ada.Numerics.Generic_Complex_Arrays General OS facilities: Ada.Directories Ada.Directories.Information Ada.Environment_Variables String hashing: Ada.Strings.Hash (generic function) Ada.Strings.Fixed.Hash (generic function) Ada.Strings.Bounded.Hash (generic function) Ada.Strings.Unbounded.Hash (generic function) Ada.Strings.Wide_Hash (generic function) Ada.Strings.Wide_Fixed.Wide_Hash (generic function) Ada.Strings.Wide_Bounded.Wide_Hash (generic function) Ada.Strings.Wide_Unbounded.Wide_Hash (generic function) Ada.Strings.Wide_Wide_Hash (generic function) Ada.Strings.Wide_Wide_Fixed.Wide_Wide_Hash (generic function) Ada.Strings.Wide_Wide_Bounded.Wide_Wide_Hash (generic function) Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Hash (generic function) Time operations: Ada.Calendar.Time_Zones Ada.Calendar.Arithmetic Ada.Calendar.Formatting Tagged types: Ada.Tags.Generic_Dispatching_Constructor (generic function) Text packages: Ada.Complex_Text_IO Ada.Text_IO.Bounded_IO Ada.Text_IO.Unbounded_IO Ada.Wide_Text_IO.Wide_Bounded_IO Ada.Wide_Text_IO.Wide_Unbounded_IO Ada.Wide_Characters Ada.Wide_Wide_Characters Wide_Wide_Character packages: Ada.Strings.Wide_Wide_Bounded Ada.Strings.Wide_Wide_Fixed Ada.Strings.Wide_Wide_Maps Ada.Strings.Wide_Wide_Maps.Wide_Wide_Constants Ada.Strings.Wide_Wide_Unbounded Ada.Wide_Wide_Text_IO Ada.Wide_Wide_Text_IO.Complex_IO Ada.Wide_Wide_Text_IO.Editing Ada.Wide_Wide_Text_IO.Text_Streams Ada.Wide_Wide_Text_IO.Wide_Wide_Bounded_IO Ada.Wide_Wide_Text_IO.Wide_Wide_Unbounded_IO Execution-time clocks: Ada.Execution_Time Ada.Execution_Time.Timers Ada.Execution_Time.Group_Budgets Dispatching: Ada.Dispatching Ada.Dispatching.EDF Ada.Dispatching.Round_Robin Timing events: Ada.Real_Time.Timing_Events Task termination procedures: Ada.Task_Termination See also Wikibook Ada Programming/Ada 83 Ada Programming/Ada 95 Ada Programming/Ada 2012 Ada Programming/Object Orientation Ada Programming/Types/access Ada Programming/Keywords Ada Programming/Keywords/and Ada Programming/Keywords/interface Ada Programming/Attributes Ada Programming/Pragmas Ada Programming/Pragmas/Restrictions Ada Programming/Libraries/Ada.Containers Ada Programming/Libraries/Ada.Directories Pages in the category Ada 2005 :Ada Programming/Ada 2005 feature External links Papers and presentations Ada 2005: Putting it all together (SIGAda 2004 presentation) GNAT and Ada 2005 (SIGAda 2004 paper) An invitation to Ada 2005, and the presentation of this paper at Ada-Europe 2004 Rationale Rationale for Ada 2005 by John Barnes: Introduction Object Oriented Model Access Types Structure and Visibility Tasking and Real-Time Exceptions, Generics, Etc. Predefined Library Containers Epilogue References Index Available as a single document for printing. Language Requirements Instructions to the Ada Rapporteur Group from SC22/WG9 for Preparation of the Amendment to ISO/IEC 8652 (10 October 2002), and a presentation of this document at SIGAda 2002 Ada Reference Manual Ada Reference Manual, ISO/IEC 8652:1995(E) with COR.1:2001 and AMD.1:2007 Annotated Ada Reference Manual, ISO/IEC 8652:1995(E) with COR.1:2001 and AMD.1:2007 (colored diffs) List of Ada Amendment drafts Ada Issues Amendment 200Y 387 Introduction to Amendment 284 New reserved words 2 252 Object.Operation notation 218 Accidental overloading when overriding 3 348 Null procedures 287 Limited aggregates allowed 326 Incomplete types 317 Partial parameter lists for formal packages 376 Interfaces.C works for C++ as well 368 Restrictions for obsolescent features 381 New Restrictions identifier No_Dependence 224 pragma Unsuppress 161 Default-initialized objects 361 Raise with message 286 Assert pragma 328 Preinstantiations of Complex_IO 301 Operations on language-defined string types 340 Mod attribute 364 Fixed-point multiply/divide 267 Fast float-to-integer conversions 321 Definition of dispatching policies 329 pragma No_Return -- procedures that never return 362 Some predefined packages should be recategorized 351 Time operations 427 Default parameters and Calendar operations 270 Stream item size control Ada 2005 *Ada 2005 *Ada 2005