It's already possible to invoke macros in item position, but macro_rules currently only ever produces macros that mr_expr(...). It should be pretty easy to make it produce both kinds of macros. Perhaps (...) => (...) defines expr macros and (...) => {...} defines item macros?
Ideally, item macros should be able to produce multiple items. This would require changing fold.rs to handle ~[@item] instead of option<@item>, as it does now. This would require a bit more hacking; perhaps changing the AST to allow sequences of items in more places is an option (it should always be semantically valid, I believe).
It's already possible to invoke macros in item position, but
macro_rulescurrently only ever produces macros thatmr_expr(...). It should be pretty easy to make it produce both kinds of macros. Perhaps(...) => (...)defines expr macros and(...) => {...}defines item macros?Ideally, item macros should be able to produce multiple items. This would require changing fold.rs to handle
~[@item]instead ofoption<@item>, as it does now. This would require a bit more hacking; perhaps changing the AST to allow sequences of items in more places is an option (it should always be semantically valid, I believe).