Re: The Red Language

[dewar@merv.cs.nyu.edu (Robert Dewar)]

Art said

<<Well, the language definition required it saying in the document that
  that was how the language worked.

  Since the main target of the language definition (written by John
  Nestor) was the implementation team (John Nestor), testing of this kind
  never showed up as an issue.  John said he would do it; later he said he
  had done it.  We believed him; why not?

  Bob: I think maybe you've been involved too long with Ada.  :-)>>

Just because a language definition says XXX does not make it so,
if the statement is vacuous.

For example, supposed we come across a statement in a language definition
that sayys

  All procedures in this language shall be octagonal.

Now we go and look up in the index what octagonal means, and if we don't
find a definition, then at best this is a comment with no normative force,
and at worst it is rubbish.

A statement that certain procedure calls shall be inlined is similarly
dubious in the absence of a definition of inlining *at an appropriate
level of abstraction* -- a definition that talks about generated code
is junk, since you cannot define the notion of generated code in abstract.

Remember that a compiler is always allowed to treat a language definition
"as-if", which means that any generated code that makes a compiler run
the code the same way as some other way is equivalent. Since inlining
has, by definition, no semantic effect, it is obvious that semantic
rules in the language can neither require it nor proscribe it.

As for "we believed him, why not?", the why not is because the claim was
on its face unsupportable!