114: Require hygienic implementation of standard macros

That is, the standard syntax forms must be implemented as if they used hygienic macros; it is not actually required that they use them. For example, (let ((eqv? #f)) (case ...)) should not throw an error of the form "#f is not a procedure". A few Schemes, notably Bigloo, have this problem today.

Neither R5RS nor R6RS requires this, but I think the Principle of Least Astonishment does.

cowan

2010-12-23 01:24:13

descriptionFor example, `(let ((eqv? equal?)) (case ...))` should not induce `case` to use `equal?` for its comparisons. Neither R5RS nor R6RS requires this, but I think the Principle of Least Astonishment does.That is, the standard syntax forms must be implemented as if they used hygienic macros; it is not actually required that they use them. For example, `(let ((eqv? #f)) (case ...))` should not throw an error of the form "#f is not a procedure". A few Schemes, notably Bigloo, have this problem today. Neither R5RS nor R6RS requires this, but I think the Principle of Least Astonishment does.

arcfide

2011-01-11 06:02:11

To note, I would contend that both standards do require this behavior from the way that I read them. That is, each built-in form is expected to be referentially transparent, its behavior unchanging despite the context.

cowan

2011-04-17 02:05:53

resolution␣worksforme

statusnewclosed

R5RS actually does require this: see opening words of 4.2. Closing this.

Ticket 114: Require hygienic implementation of standard macros