Re: [Scheme-reports] Comments on revised WG1 charter

[John Cowan <cowan@x>]

Brian Harvey scripsit:

> To expand on that:  I believe that the WG1 language should have only one
> semantics.

Which must, in the nature of your claims, be an operational one, as you
are evidently completely opposed to denotational semantics of any sort.

> It should be mode-free, for the same reason that text editors
> and all other interactive programs should be mode-free.

Things weren't difficult enough, but now you have to reawaken the
vi/Emacs wars?  I'm using the highly modal "ex" editor to write these
words, and very glad of it too.

In any case, mode-free means context-free; in a mode-free system, each
keystroke and mouse gesture must mean one and only one thing at all times.
In particular, there can be no menus, since keystrokes and gestures mean
one thing in a menu and something else in other parts of the screen.

> In my opinion, this rules out any structure that requires the user
> to keep track of ideas such as "compile time,"  In WG1 Scheme, as
> in all traditional Schemes, no matter what happens under the hood,
> for the user there is only one "time,"

As far as anyone knows, either you accept the notion that macros
are expanded before they're interpreted, or you compel the domain of
interpretation to include first-class environments, the use of which
makes reasoning about code impossible -- all code is a black box, the
effect of which cannot be determined except by running it.

> I don't know whether this was carefully thought out by the SC or just an
> accident, but I'm disturbed by the fact that the discussion of compatibility
> with R5RS and other traditional Schemes under "Requirements and Goals" uses
> "should," whereas the discussion of compatibility with WG2 (\approx R6RS)
> under "Coordination with WG2" uses "must."  

Note that no Scheme version, with the sole exception of R5RS, has ever
been entirely backwards-compatible with its predecessor.  My features
chart at http://tinyurl.com/feature-groups is misleading in that respect
because it omits the R2RS and R3RS features that were dropped in R3RS
or R4RS.

> Under "Membership," does "should endorse the goals of the working group"
> mean that agreeing with the "must" about WG2 compatibility is a requirement
> for membership?  

It means that there is intended to be a separation between
charter-designing and standardizing.  This is the period when anyone
can try to get the charter changed.  After that is over, you have two
choices: accept the charter and apply to join one or both WGs, or reject
the charter and snipe from the sidelines.  The WGs will have enough to
do without refighting charter battles continuously.

-- 
Clear?  Huh!  Why a four-year-old child         John Cowan
could understand this report.  Run out          cowan@x
and find me a four-year-old child.  I           http://www.ccil.org/~cowan
can't make head or tail out of it.
        --Rufus T. Firefly on government reports

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