bjoernager/rust
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Tweak ItemDecorator API

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The old method of building up a list of items and threading it through
all of the decorators was unwieldy and not really scalable as
non-deriving ItemDecorators become possible. The API is now that the
decorator gets an immutable reference to the item it's attached to, and
a callback that it can pass new items to. If we want to add syntax
extensions that can modify the item they're attached to, we can add that
later, but I think it'll have to be separate from ItemDecorator to avoid
strange ordering issues.
This commit is contained in:
Steven Fackler 2014-02-12 23:53:52 -08:00
parent 68129d299b
commit 3c02749ad8
18 changed files with 76 additions and 74 deletions
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16
src/libsyntax/ext/expand.rs
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@ -29,7 +29,6 @@ use visit::Visitor;
use util::small_vector::SmallVector;
use std::cast;
use std::vec;
use std::unstable::dynamic_lib::DynamicLibrary;
use std::os;
@ -220,8 +219,9 @@ pub fn expand_mod_items(module_: &ast::Mod, fld: &mut MacroExpander) -> ast::Mod
// For each item, look through the attributes. If any of them are
// decorated with "item decorators", then use that function to transform
// the item into a new set of items.
let new_items = vec::flat_map(module_.items, |item| {
item.attrs.rev_iter().fold(~[*item], |items, attr| {
let mut new_items = module_.items.clone();
for item in module_.items.iter() {
for attr in item.attrs.rev_iter() {
let mname = attr.name();
match fld.extsbox.find(&intern(mname.get())) {
@ -234,14 +234,14 @@ pub fn expand_mod_items(module_: &ast::Mod, fld: &mut MacroExpander) -> ast::Mod
span: None
}
});
let r = dec_fn(fld.cx, attr.span, attr.node.value, items);
dec_fn(fld.cx, attr.span, attr.node.value, *item,
|item| new_items.push(item));
fld.cx.bt_pop();
r
},
_ => items,
_ => {},
}
})
});
}
}
ast::Mod {
items: new_items,