Lies, damn lies!

Laurent Martelli martelli@iie.cnam.fr
27 May 1999 10:22:02 +0200


>>>>> "Jecel" == Jecel Assumpcao <jecel@lsi.usp.br> writes:

  Jecel> Francois-Rene Rideau wrote:
  >> A common conclusion of John's and my studies is that a language,
  >> to be universal (== Turing-equivalent), must be able to quote
  >> code non-intrusively in a source-code-structure-preserving way,
  >> so as to write metaprograms that manipulate the quoted code.

  Jecel> Now you got me really confused! Every explanation I have ever
  Jecel> seen of Turing Machines have always presented them with a
  Jecel> Harvard Architecture instead of a Von Neumann one: they store
  Jecel> their state in an infinite tape of symbols and their code in
  Jecel> a separate table representing a finite state machine. Only
  Jecel> the tape can be accessed and changed, not the table.

Code is data, and data is code. The data on the tape can be considered
a source to be interpreted by the state machine.

-- 
Laurent Martelli
martelli@iie.cnam.fr