Alpha-renamed top-level visit_* functions to walk_*.
(Motivation: Distinguish visit action and recursive traversal.)
Abstract over `&mut self` rather than over `@mut self`.
This required some acrobatics, notably the
`impl<E> Visitor<E> for @mut Visitor<E>`
and corresponding introduction of `@mut Visitor` and some local `let
mut` bindings.
Remove oldvisit reference.
Added default implementations for all of the Visitor trait methods.
Note that both `visit_expr_post` and `visit_ty` are no-op's by
default, just like they are in `oldvisit::default_visitor`.
Refactoring: extract logic to ease swapping visit for oldvisit (hopefully).
Replace these with three functions based on iterators: collect, fold,
and fold_. The mapping part is replaced by iterator .map(), so the part
that these functions do is to accumulate the final Result<,> value.
* `result::collect` gathers `Iterator<Result<V, U>>` to `Result<~[V], U>`
* `result::fold` folds `Iterator<Result<T, E>>` to `Result<V, E>`
* `result::fold_` folds `Iterator<Result<T, E>>` to `Result<(), E>`
Remove the only use of either::partition since it was better
accomplished with vector methods.
Update either::partition so that it sizes the vectors correctly before
it starts.
- Methodyfied the string ascii extionsion functions - They got added recently, I wrapped them in a trait.
- Added `into_owned()` method for vectors - similar to `Str`'s `into_owned()` function, allows to convert to a owned vector without making a copy if the source is a owned vector.
- Added `or_some` method to option - similar to `unwrap_or_default`, but keeps the values wrapped in an `Option`. Useful for `Option` chains, eg Iterator impls.
- Added `DoubleEndedIterator` impl to `Option` - Just for compatibility with generic Iterator functions.
- Renamed nil.rs to unit.rs - the type got renamed ages ago, it's time the source file is as well.
If they are on the trait then it is extremely annoying to use them as
generic parameters to a function, e.g. with the iterator param on the trait
itself, if one was to pass an Extendable<int> to a function that filled it
either from a Range or a Map<VecIterator>, one needs to write something
like:
fn foo<E: Extendable<int, Range<int>> +
Extendable<int, Map<&'self int, int, VecIterator<int>>>
(e: &mut E, ...) { ... }
since using a generic, i.e. `foo<E: Extendable<int, I>, I: Iterator<int>>`
means that `foo` takes 2 type parameters, and the caller has to specify them
(which doesn't work anyway, as they'll mismatch with the iterators used in
`foo` itself).
This patch changes it to:
fn foo<E: Extendable<int>>(e: &mut E, ...) { ... }
