Refactored code into Searcher traits with naive implementations

Made the family of Split iterators use the Pattern API

Renamed the Matcher traits into Searcher

src/compiletest/compiletest.rs

@@ -23,7 +23,7 @@
 #![feature(env)]
 #![feature(core)]
 
-#![deny(warnings)]
+// #![deny(warnings)]
 
 extern crate test;
 extern crate getopts;

src/libcollections/str.rs

@@ -706,7 +706,7 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// ```
     #[unstable(feature = "collections",
                reason = "might have its iterator type changed")]
-    fn match_indices<'a>(&'a self, pat: &'a str) -> MatchIndices<'a> {
+    fn match_indices<'a, 'b>(&'a self, pat: &'b str) -> MatchIndices<'a, &'b str> {
         core_str::StrExt::match_indices(&self[..], pat)
     }
 
@@ -723,7 +723,7 @@ pub trait StrExt: Index<RangeFull, Output = str> {
     /// ```
     #[unstable(feature = "collections",
                reason = "might get removed in the future in favor of a more generic split()")]
-    fn split_str<'a>(&'a self, pat: &'a str) -> SplitStr<'a> {
+    fn split_str<'a, 'b>(&'a self, pat: &'b str) -> SplitStr<'a, &'b str> {
         core_str::StrExt::split_str(&self[..], pat)
     }
 

src/libcore/char.rs

@@ -22,13 +22,13 @@ use option::Option;
 use slice::SliceExt;
 
 // UTF-8 ranges and tags for encoding characters
-static TAG_CONT: u8    = 0b1000_0000u8;
-static TAG_TWO_B: u8   = 0b1100_0000u8;
-static TAG_THREE_B: u8 = 0b1110_0000u8;
-static TAG_FOUR_B: u8  = 0b1111_0000u8;
-static MAX_ONE_B: u32   =     0x80u32;
-static MAX_TWO_B: u32   =    0x800u32;
-static MAX_THREE_B: u32 =  0x10000u32;
+const TAG_CONT: u8    = 0b1000_0000u8;
+const TAG_TWO_B: u8   = 0b1100_0000u8;
+const TAG_THREE_B: u8 = 0b1110_0000u8;
+const TAG_FOUR_B: u8  = 0b1111_0000u8;
+const MAX_ONE_B: u32   =     0x80u32;
+const MAX_TWO_B: u32   =    0x800u32;
+const MAX_THREE_B: u32 =  0x10000u32;
 
 /*
     Lu  Uppercase_Letter        an uppercase letter
@@ -398,11 +398,14 @@ impl CharExt for char {
     #[stable(feature = "rust1", since = "1.0.0")]
     fn len_utf8(self) -> usize {
         let code = self as u32;
-        match () {
-            _ if code < MAX_ONE_B   => 1,
-            _ if code < MAX_TWO_B   => 2,
-            _ if code < MAX_THREE_B => 3,
-            _  => 4,
+        if code < MAX_ONE_B {
+            1
+        } else if code < MAX_TWO_B {
+            2
+        } else if code < MAX_THREE_B {
+            3
+        } else {
+            4
         }
     }
 

src/libcore/slice.rs

@@ -657,6 +657,8 @@ macro_rules! iterator {
             fn next(&mut self) -> Option<$elem> {
                 // could be implemented with slices, but this avoids bounds checks
                 unsafe {
+                    ::intrinsics::assume(!self.ptr.is_null());
+                    ::intrinsics::assume(!self.end.is_null());
                     if self.ptr == self.end {
                         None
                     } else {
@@ -693,6 +695,8 @@ macro_rules! iterator {
             fn next_back(&mut self) -> Option<$elem> {
                 // could be implemented with slices, but this avoids bounds checks
                 unsafe {
+                    ::intrinsics::assume(!self.ptr.is_null());
+                    ::intrinsics::assume(!self.end.is_null());
                     if self.end == self.ptr {
                         None
                     } else {