Re: Multiple dispatch

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

On 15.06.11 17:18, Yannick Duchêne (Hibou57) wrote:
> Le Wed, 15 Jun 2011 16:59:13 +0200, Georg Bauhaus
> <rm.dash-bauhaus@futureapps.de> a écrit:
>> You could build something around (external) tag names.
>>
>> Or you could build a compiler into an ASIS program or
>> vice versa. This should be a pretty powerful team.
> If he/she was talking about runtime introspection, the former is more advised
> (I supposed runtime introspection).

Hypothetically, you compile GNAT into a program that uses
the ASIS libraries (seems redundant, but anyway). Then,
the compiler, being part of the running program, may be
able to replace parts of the running program with
new ones that have new types in them. Based on the
program or based on information gathered at runtime.
There is

- code compiled from sources input at runtime;
  information about previous compiler runs is preserved

- code compiled from sources produced by some ASIS
  machinery;  the sources may be the product of
  the running program

- code that is possible to make because the
  compiler knows enough about the program that it has
  produced. For example, when a compiler knows the
  layout of any dispatch tables, then it can compute
  more elaborate dispatch tables as it wishes.
  Providing for code injection, say.