At Mon, 28 Jul 2014 23:45:13 -0400, "Alexander D. Knauth" wrote: > So since “no-lambda.rkt” doesn’t have to provide lambda for #λ to > work, why would you have to provide GENSYM? That’s (part of) what I’m > trying to figure out. Why does one work and the other not work?
If I understand, you're asking about the require: namespace mismatch; reference to a module that is not available reference phase: 0 referenced module: .... error that you get with a GENSYM example, particularly in contrast to the absence of that error when referencing `lambda` instead. Normally, you get access to `lambda` to a `require` chain that causes the module providing `lambda` to be instantiated along with the module that contains the `lambda` reference. When your reader creates a `lambda` identifier with lexical context, things also work out, but only the module providing `lambda` happens to be referenced through `require`s from the referencing module, anyway. No such `require` chain happens to be around to reach the implementation of GENSYM when you get the error above. That is, the module is unavailable because there was no `require` chain to make it available. The disconnect between binding and instantiation is the key problem with a reader that produces a syntax object with context. We don't yet know how to connect them (at the right phase). ____________________ Racket Users list: http://lists.racket-lang.org/users
