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Re: [Scheme-reports] Write procedure is not backwards compatible
Jonathan Rees scripsit:
> May I suggest splitting "Language changes since R5RS" into two parts:
> 1. What someone needs to know when porting from R5RS to R7RS
> (i.e. incompatible changes)
> 2. What someone who knows R5RS would need to learn when reading R7RS
> programs (mostly compatible extensions I hope)
> Looks like #1 will be quite short, but the relevant items are currently
> spread around.
Editorial ticket #446 filed.
> Similarly, R6RS-main incompatibilities may fall into classes,
> although it looks like most of the ones listed are either retractions,
> limitations, or "R7RS doesn't have x but it has y instead". Maybe
> there are extensions that aren't listed here because they're in the
> R5RS-diff section?
This list is meant to be incompatibilities only, not compatible
> A bit more detail on the bullet "Case insensitivity is now the default"
> would be helpful, since it's hard to tell from reading R5RS what its
> position is on the subject.
Section 2 of R5RS says "Upper and lower case forms of a letter are
never distinguished except within character and string constants. For
example, Foo is the same identiﬁer as FOO, and #x1AB is the same number
as #X1ab." I don't see any way to misinterpret that.
> If there are putatively conformant case-sensitive R5RS implementations
There are a bunch of implementations which are R5RS-conformant except for
case sensitivity, which I think is why case sensitivity became part of
both R6RS and R7RS. See http://trac.sacrideo.us/wg/wiki/CaseInsensitivity
> then this is an incompatible change and you should say so.
It is indeed an incompatible change.
I Hope, Sir, that we are not John Cowan
mutually Un-friended by this cowan@x
Difference which hath happened http://www.ccil.org/~cowan
betwixt us. --Thomas Fuller, Appeal to Injured Innocence (1659)
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