There's an edge case of 'module' when only one form is provided which results in that form being partially expanded to determine if such expansion would lead to a #%plain-module-begin form. Otherwise (more than one form provided) they are wrapped in #%module-begin with no partial expansion occurring.
I think this might be causing the discrepancy you witnessed. >From the docs (https://docs.racket-lang.org/reference/module.html): If a single form is provided, then it is partially expanded in a module-begin context. If the expansion leads to #%plain-module-begin, then the body of the #%plain-module-begin is the body of the module. If partial expansion leads to any other primitive form, then the form is wrapped with #%module-begin using the lexical context of the module body; this identifier must be bound by the initial module-path import, and its expansion must produce a #%plain-module-begin to supply the module body. Finally, if multiple forms are provided, they are wrapped with #%module-begin, as in the case where a single form does not expand to #%plain-module-begin. (This response was adapted from one of my earlier replies to the mailing list. Search racket-users for "perplexed by macro-expansion behavior near #%module-begin" for more context). Best, Michael On Sat, Jan 2, 2021 at 8:26 PM Sage Gerard <s...@sagegerard.com> wrote: > Why does Racket handle modules with exactly one form differently? > > I ran into a bug where modules in my module language won't expand if the > modules have exactly one form, so I'm just curious. > > (Wild guess: It's Racket's way of checking for a shortcut to end expansion > earlier) > > *~slg* > > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/OVvZ0OK4_PfyvXCWfuvzDWBM5-ellmDvNmWchVmsCwAJb_rbSZkCkyraakcGsEMSCl2BsLsWtMXFhQcXY75IKhYiYYGQQEI7lVXLgGBbTCc%3D%40sagegerard.com > <https://groups.google.com/d/msgid/racket-users/OVvZ0OK4_PfyvXCWfuvzDWBM5-ellmDvNmWchVmsCwAJb_rbSZkCkyraakcGsEMSCl2BsLsWtMXFhQcXY75IKhYiYYGQQEI7lVXLgGBbTCc%3D%40sagegerard.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CACehHmC0ZMqoGv8SF8jiEkLJfE4SL1SKsCuJUT1W2qYDORo19Q%40mail.gmail.com.
