Re: [Scheme-reports] Boolean hemlines

[John Cowan <cowan@x>]

Alan Watson scripsit:

> A long time ago, some people made the decision that #t/#f were in
> some sense better than #!true/#!false. More recently, the WG1 have
> made a different decision that #true/#false are in some sense better
> than #t/#f.

The cases aren't really comparable.  #!true and #!false were removed from
the language; #t and #f aren't being removed.

> This decision is not without cost. If an R7RS Scheme writes a boolean
> datum as #true or #false, it likely cannot be read by a R4RS, R5RS,
> or R6RS Scheme. It is unrealistic and probably undesirable to require
> perfect compatibility between iterations of Scheme, but changing the
> spelling a fundamental data is perhaps unexpected. The WG1 needs to
> decide if this cost is acceptable, and if not either revert their
> decision to allow #true/#false or require write to produce #t/#f.

I think that's a quality of implementation issue.  Currently Chibi is
the only Scheme that accepts #true and #false, and it always prints
#t and #f.

-- 
John Cowan                                cowan@x
I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
han mathon ne chae, a han noston ne 'wilith.  --Galadriel, LOTR:FOTR

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