auto merge of #6056 : thestinger/rust/iter, r=catamorphism

The existing adaptors like `map` in the `iter` module are very flawed because they only work for `BaseIter` implementations. There are many internal iterator implementations in the standard library like the set methods (`difference`, `symmetric_difference`, `intersection`, `union`) and the `range` functions that only share the `for` loop protocol in common.

The internal iterator adaptors should be implemented to work on any implementation of that protocol, rather than just a method called `each` taking `&self`.

This just moves `iter.rs` to `old_iter.rs` and begins work on documenting and implementing a nicer module.

Author: bors

doc/tutorial.md

@@ -1981,7 +1981,7 @@ struct TimeBomb {
 
 impl Drop for TimeBomb {
     fn finalize(&self) {
-        for iter::repeat(self.explosivity) {
+        for old_iter::repeat(self.explosivity) {
             io::println("blam!");
         }
     }

src/libcore/at_vec.rs

@@ -12,7 +12,7 @@
 
 use cast::transmute;
 use kinds::Copy;
-use iter;
+use old_iter;
 use option::Option;
 use ptr::addr_of;
 use sys;
@@ -125,7 +125,7 @@ pub fn map<T, U>(v: &[T], f: &fn(x: &T) -> U) -> @[U] {
  * Creates an immutable vector of size `n_elts` and initializes the elements
  * to the value returned by the function `op`.
  */
-pub fn from_fn<T>(n_elts: uint, op: iter::InitOp<T>) -> @[T] {
+pub fn from_fn<T>(n_elts: uint, op: old_iter::InitOp<T>) -> @[T] {
     do build_sized(n_elts) |push| {
         let mut i: uint = 0u;
         while i < n_elts { push(op(i)); i += 1u; }

src/libcore/core.rc

@@ -99,9 +99,10 @@ pub use container::{Container, Mutable};
 pub use vec::{CopyableVector, ImmutableVector};
 pub use vec::{ImmutableEqVector, ImmutableCopyableVector};
 pub use vec::{OwnedVector, OwnedCopyableVector, MutableVector};
-pub use iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
-pub use iter::{CopyableOrderedIter, CopyableNonstrictIter, Times};
-pub use iter::{ExtendedMutableIter};
+pub use old_iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
+pub use old_iter::{CopyableOrderedIter, CopyableNonstrictIter};
+pub use old_iter::{ExtendedMutableIter};
+pub use iter::Times;
 
 pub use num::{Num, NumCast};
 pub use num::{Orderable, Signed, Unsigned, Integer};
@@ -188,6 +189,7 @@ pub mod from_str;
 #[path = "num/num.rs"]
 pub mod num;
 pub mod iter;
+pub mod old_iter;
 pub mod iterator;
 pub mod to_str;
 pub mod to_bytes;

src/libcore/hashmap.rs

@@ -16,9 +16,9 @@
 use container::{Container, Mutable, Map, Set};
 use cmp::{Eq, Equiv};
 use hash::Hash;
-use iter::BaseIter;
+use old_iter::BaseIter;
 use hash::Hash;
-use iter;
+use old_iter;
 use option::{None, Option, Some};
 use rand::RngUtil;
 use rand;
@@ -757,12 +757,12 @@ impl<T:Hash + Eq> Set<T> for HashSet<T> {
     /// Return true if the set has no elements in common with `other`.
     /// This is equivalent to checking for an empty intersection.
     fn is_disjoint(&self, other: &HashSet<T>) -> bool {
-        iter::all(self, |v| !other.contains(v))
+        old_iter::all(self, |v| !other.contains(v))
     }
 
     /// Return true if the set is a subset of another
     fn is_subset(&self, other: &HashSet<T>) -> bool {
-        iter::all(self, |v| other.contains(v))
+        old_iter::all(self, |v| other.contains(v))
     }
 
     /// Return true if the set is a superset of another