Re: Ada on Raspberry Pi: new article in MagPi issue 8

[Georg Bauhaus <rm.dash-bauhaus@futureapps.de>]

On 02.12.12 18:19, Luke A. Guest wrote:
> 4) Representation clauses for mapping to hardware or C API's

Based on what John McCormick found to be so valuable about Ada's
expressive fundamental type system, I'd like to humbly suggest that
it be made known, and preferred to implementation defined C like types
such as Integer. In particular, Ada's scalar types allow programmers
to just say what they already know instead of thinking hard
about which int-like type might somehow match what they cannot
express in the fundamental type system (of C, or Ada's library types),
such as range 1 .. 80_000 (vs C's INT_MAX/Ada's System.Max_Int):

    "Upon reading the project listings and team member diaries, I concluded
that the major advantages of Ada for these students were, in order of importance:

    "* Modeling of scalar objects.
          + Strong typing.
          + Range constraints.
          + Enumeration types.
    * Parameter modes that reflect the problem rather than the mechanism.
    * Named parameter association.
    * Arrays whose indices do not have to begin at zero.
    * Representation clauses for device registers
      (record field selection rather than bit masks).
    * Higher level of abstraction for tasking
      (rendezvous rather than semaphores).
    * Exception handling.

"Compilation model detects obsolete units

    "I found my original hypothesis, that the major problem was C's low-level
tasking mechanism, to be incorrect. While Ada's high level of abstraction for
tasking was helpful to the students, it was the accurate modeling of scalar
quantities that contributed the most to Ada's success in this course."

Crosstalk article also found here
http://archive.adaic.com/projects/atwork/trains.html