librustc: Remove unique vector patterns from the language.

Preparatory work for removing unique vectors from the language, which is
itself preparatory work for dynamically sized types.

src/libextra/test.rs

@@ -315,13 +315,16 @@ pub fn opt_shard(maybestr: Option<~str>) -> Option<(uint,uint)> {
     match maybestr {
         None => None,
         Some(s) => {
-            match s.split('.').to_owned_vec() {
+            let vector = s.split('.').to_owned_vec();
-                [a, b] => match (from_str::<uint>(a), from_str::<uint>(b)) {
+            if vector.len() == 2 {
-                    (Some(a), Some(b)) => Some((a,b)),
+                match (from_str::<uint>(vector[0]),
-                    _ => None
+                       from_str::<uint>(vector[1])) {
-                },
+                    (Some(a), Some(b)) => Some((a, b)),
                     _ => None
                 }
+            } else {
+                None
+            }
         }
     }
 }

src/libnative/io/timer_other.rs

@@ -130,15 +130,14 @@ fn helper(input: libc::c_int, messages: Port<Req>) {
     }
 
     'outer: loop {
-        let timeout = match active {
+        let timeout = if active.len() == 0 {
             // Empty array? no timeout (wait forever for the next request)
-            [] => ptr::null(),
+            ptr::null()
-
+        } else {
-            [~Inner { target, .. }, ..] => {
             let now = now();
             // If this request has already expired, then signal it and go
             // through another iteration
-                if target <= now {
+            if active[0].target <= now {
                 signal(&mut active, &mut dead);
                 continue;
             }
@@ -146,11 +145,10 @@ fn helper(input: libc::c_int, messages: Port<Req>) {
             // The actual timeout listed in the requests array is an
             // absolute date, so here we translate the absolute time to a
             // relative time.
-                let tm = target - now;
+            let tm = active[0].target - now;
             timeout.tv_sec = (tm / 1000) as libc::time_t;
             timeout.tv_usec = ((tm % 1000) * 1000) as libc::suseconds_t;
             &timeout as *libc::timeval
-            }
         };
 
         imp::fd_set(&mut set, input);

src/libnum/bigint.rs

@@ -495,24 +495,23 @@ impl ToPrimitive for BigUint {
     #[cfg(target_word_size = "32")]
     #[inline]
     fn to_u64(&self) -> Option<u64> {
-        match self.data {
+        match self.data.len() {
-            [] => {
+            0 => Some(0),
-                Some(0)
+            1 => Some(self.data[0] as u64),
+            2 => {
+                Some(BigDigit::to_uint(self.data[1], self.data[0]) as u64)
             }
-            [n0] => {
+            3 => {
-                Some(n0 as u64)
+                let n_lo = BigDigit::to_uint(self.data[1], self.data[0]) as
-            }
+                    u64;
-            [n0, n1] => {
+                let n_hi = self.data[2] as u64;
-                Some(BigDigit::to_uint(n1, n0) as u64)
-            }
-            [n0, n1, n2] => {
-                let n_lo = BigDigit::to_uint(n1, n0) as u64;
-                let n_hi = n2 as u64;
                 Some((n_hi << 32) + n_lo)
             }
-            [n0, n1, n2, n3] => {
+            4 => {
-                let n_lo = BigDigit::to_uint(n1, n0) as u64;
+                let n_lo = BigDigit::to_uint(self.data[1], self.data[0])
-                let n_hi = BigDigit::to_uint(n3, n2) as u64;
+                    as u64;
+                let n_hi = BigDigit::to_uint(self.data[3], self.data[2])
+                    as u64;
                 Some((n_hi << 32) + n_lo)
             }
             _ => None
@@ -522,16 +521,10 @@ impl ToPrimitive for BigUint {
     #[cfg(target_word_size = "64")]
     #[inline]
     fn to_u64(&self) -> Option<u64> {
-        match self.data {
+        match self.data.len() {
-            [] => {
+            0 => Some(0),
-                Some(0)
+            1 => Some(self.data[0] as u64),
-            }
+            2 => Some(BigDigit::to_uint(self.data[1], self.data[0]) as u64),
-            [n0] => {
-                Some(n0 as u64)
-            }
-            [n0, n1] => {
-                Some(BigDigit::to_uint(n1, n0) as u64)
-            }
             _ => None
         }
     }

src/librustc/middle/lint.rs

@@ -1213,15 +1213,13 @@ fn check_unused_mut_pat(cx: &Context, p: &ast::Pat) {
         ast::PatIdent(ast::BindByValue(ast::MutMutable),
                       ref path, _) if pat_util::pat_is_binding(cx.tcx.def_map, p)=> {
             // `let mut _a = 1;` doesn't need a warning.
-            let initial_underscore = match path.segments {
+            let initial_underscore = if path.segments.len() == 1 {
-                [ast::PathSegment { identifier: id, .. }] => {
+                token::get_ident(path.segments[0].identifier).get()
-                    token::get_ident(id).get().starts_with("_")
+                                                             .starts_with("_")
-                }
+            } else {
-                _ => {
                 cx.tcx.sess.span_bug(p.span,
-                                         "mutable binding that doesn't \
+                                     "mutable binding that doesn't consist \
-                                         consist of exactly one segment");
+                                      of exactly one segment")
-                }
             };
 
             let used_mut_nodes = cx.tcx.used_mut_nodes.borrow();

src/librustc/middle/typeck/check/_match.rs

@@ -603,7 +603,17 @@ pub fn check_pat(pcx: &pat_ctxt, pat: &ast::Pat, expected: ty::t) {
           ty::ty_vec(mt, vstore) => {
             let region_var = match vstore {
                 ty::vstore_slice(r) => r,
-                ty::vstore_uniq | ty::vstore_fixed(_) => {
+                ty::vstore_uniq => {
+                    fcx.type_error_message(pat.span,
+                                           |_| {
+                                            ~"unique vector patterns are no \
+                                              longer supported"
+                                           },
+                                           expected,
+                                           None);
+                    default_region_var
+                }
+                ty::vstore_fixed(_) => {
                     default_region_var
                 }
             };

src/librustc/middle/typeck/check/mod.rs

@@ -3894,8 +3894,11 @@ pub fn ast_expr_vstore_to_vstore(fcx: @FnCtxt,
         ast::ExprVstoreUniq => ty::vstore_uniq,
         ast::ExprVstoreSlice | ast::ExprVstoreMutSlice => {
             match e.node {
-                ast::ExprLit(..) |
+                ast::ExprLit(..) => {
-                ast::ExprVec([], _) => {
+                    // string literals and *empty slices* live in static memory
+                    ty::vstore_slice(ty::ReStatic)
+                }
+                ast::ExprVec(ref elements, _) if elements.len() == 0 => {
                     // string literals and *empty slices* live in static memory
                     ty::vstore_slice(ty::ReStatic)
                 }

src/librustdoc/passes.rs

@@ -311,10 +311,9 @@ pub fn unindent(s: &str) -> ~str {
         }
     });
 
-    match lines {
+    if lines.len() >= 1 {
-        [head, .. tail] => {
+        let mut unindented = ~[ lines[0].trim() ];
-            let mut unindented = ~[ head.trim() ];
+        unindented.push_all(lines.tail().map(|&line| {
-            unindented.push_all(tail.map(|&line| {
             if line.is_whitespace() {
                 line
             } else {
@@ -323,8 +322,8 @@ pub fn unindent(s: &str) -> ~str {
             }
         }));
         unindented.connect("\n")
-        }
+    } else {
-        [] => s.to_owned()
+        s.to_owned()
     }
 }
 

src/libsyntax/ext/deriving/clone.rs

@@ -97,13 +97,11 @@ fn cs_clone(
                                                                  name))
     }
 
-    match *all_fields {
+    if all_fields.len() >= 1 && all_fields[0].name.is_none() {
-        [FieldInfo { name: None, .. }, ..] => {
         // enum-like
         let subcalls = all_fields.map(subcall);
         cx.expr_call_ident(trait_span, ctor_ident, subcalls)
-        },
+    } else {
-        _ => {
         // struct-like
         let fields = all_fields.map(|field| {
             let ident = match field.name {
@@ -122,5 +120,4 @@ fn cs_clone(
             cx.expr_struct_ident(trait_span, ctor_ident, fields)
         }
     }
-    }
 }

src/libsyntax/ext/deriving/generic.rs

@@ -663,10 +663,11 @@ impl<'a> MethodDef<'a> {
         }
 
         // transpose raw_fields
-        let fields = match raw_fields {
+        let fields = if raw_fields.len() > 0 {
-            [ref self_arg, .. rest] => {
+            raw_fields[0].iter()
-                self_arg.iter().enumerate().map(|(i, &(span, opt_id, field))| {
+                         .enumerate()
-                    let other_fields = rest.map(|l| {
+                         .map(|(i, &(span, opt_id, field))| {
+                let other_fields = raw_fields.tail().map(|l| {
                     match &l[i] {
                         &(_, _, ex) => ex
                     }
@@ -678,10 +679,10 @@ impl<'a> MethodDef<'a> {
                     other: other_fields
                 }
             }).collect()
-            }
+        } else {
-            [] => { cx.span_bug(trait_.span,
+            cx.span_bug(trait_.span,
-                                "no self arguments to non-static method \
+                        "no self arguments to non-static method in generic \
-                                in generic `deriving`") }
+                         `deriving`")
         };
 
         // body of the inner most destructuring match

src/libsyntax/ext/deriving/mod.rs

@@ -54,7 +54,10 @@ pub fn expand_meta_deriving(cx: &mut ExtCtxt,
         MetaNameValue(_, ref l) => {
             cx.span_err(l.span, "unexpected value in `deriving`");
         }
-        MetaWord(_) | MetaList(_, []) => {
+        MetaWord(_) => {
+            cx.span_warn(mitem.span, "empty trait list in `deriving`");
+        }
+        MetaList(_, ref titems) if titems.len() == 0 => {
             cx.span_warn(mitem.span, "empty trait list in `deriving`");
         }
         MetaList(_, ref titems) => {

src/libsyntax/ext/deriving/show.rs

@@ -74,7 +74,8 @@ fn show_substructure(cx: &mut ExtCtxt, span: Span,
     // Getting harder... making the format string:
     match *substr.fields {
         // unit struct/nullary variant: no work necessary!
-        Struct([]) | EnumMatching(_, _, []) => {}
+        Struct(ref fields) if fields.len() == 0 => {}
+        EnumMatching(_, _, ref fields) if fields.len() == 0 => {}
 
         Struct(ref fields) | EnumMatching(_, _, ref fields) => {
             if fields[0].name.is_none() {

src/libsyntax/ext/env.rs

@@ -40,7 +40,7 @@ pub fn expand_option_env(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
 pub fn expand_env(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
     -> base::MacResult {
     let exprs = match get_exprs_from_tts(cx, sp, tts) {
-        Some([]) => {
+        Some(ref exprs) if exprs.len() == 0 => {
             cx.span_err(sp, "env! takes 1 or 2 arguments");
             return MacResult::dummy_expr(sp);
         }

src/libsyntax/ext/expand.rs

@@ -647,14 +647,10 @@ impl Visitor<()> for NewNameFinderContext {
                     &ast::Path {
                         global: false,
                         span: _,
-                        segments: [
+                        segments: ref segments
-                            ast::PathSegment {
+                    } if segments.len() == 1 => {
-                                identifier: id,
+                        self.ident_accumulator.push(segments[0].identifier)
-                                lifetimes: _,
-                                types: _
                     }
-                        ]
-                    } => self.ident_accumulator.push(id),
                     // I believe these must be enums...
                     _ => ()
                 }
@@ -1187,7 +1183,12 @@ foo_module!()
         let bindings = name_finder.ident_accumulator;
 
         let cxbinds: ~[&ast::Ident] =
-            bindings.iter().filter(|b| "xx" == token::get_ident(**b).get()).collect();
+            bindings.iter().filter(|b| {
+                let ident = token::get_ident(**b);
+                let string = ident.get();
+                "xx" == string
+            }).collect();
+        let cxbinds: &[&ast::Ident] = cxbinds;
         let cxbind = match cxbinds {
             [b] => b,
             _ => fail!("expected just one binding for ext_cx")

src/libsyntax/parse/mod.rs

@@ -363,40 +363,48 @@ mod test {
     // check the token-tree-ization of macros
     #[test] fn string_to_tts_macro () {
         let tts = string_to_tts(~"macro_rules! zip (($a)=>($a))");
+        let tts: &[ast::TokenTree] = tts;
         match tts {
             [ast::TTTok(_,_),
              ast::TTTok(_,token::NOT),
              ast::TTTok(_,_),
-             ast::TTDelim(delim_elts)] =>
+             ast::TTDelim(delim_elts)] => {
-                match *delim_elts {
+                let delim_elts: &[ast::TokenTree] = *delim_elts;
+                match delim_elts {
                     [ast::TTTok(_,token::LPAREN),
                      ast::TTDelim(first_set),
                      ast::TTTok(_,token::FAT_ARROW),
                      ast::TTDelim(second_set),
-                 ast::TTTok(_,token::RPAREN)] =>
+                     ast::TTTok(_,token::RPAREN)] => {
-                    match *first_set {
+                        let first_set: &[ast::TokenTree] = *first_set;
+                        match first_set {
                             [ast::TTTok(_,token::LPAREN),
                              ast::TTTok(_,token::DOLLAR),
                              ast::TTTok(_,_),
-                     ast::TTTok(_,token::RPAREN)] =>
+                             ast::TTTok(_,token::RPAREN)] => {
-                        match *second_set {
+                                let second_set: &[ast::TokenTree] =
+                                    *second_set;
+                                match second_set {
                                     [ast::TTTok(_,token::LPAREN),
                                      ast::TTTok(_,token::DOLLAR),
                                      ast::TTTok(_,_),
-                         ast::TTTok(_,token::RPAREN)] =>
+                                     ast::TTTok(_,token::RPAREN)] => {
-                            assert_eq!("correct","correct"),
+                                        assert_eq!("correct","correct")
+                                    }
                                     _ => assert_eq!("wrong 4","correct")
+                                }
                             },
                             _ => {
                                 error!("failing value 3: {:?}",first_set);
                                 assert_eq!("wrong 3","correct")
                             }
+                        }
                     },
                     _ => {
                         error!("failing value 2: {:?}",delim_elts);
                         assert_eq!("wrong","correct");
                     }
-
+                }
             },
             _ => {
                 error!("failing value: {:?}",tts);

src/libsyntax/util/small_vector.rs

@@ -81,7 +81,13 @@ impl<T> SmallVector<T> {
     pub fn expect_one(self, err: &'static str) -> T {
         match self {
             One(v) => v,
-            Many([v]) => v,
+            Many(v) => {
+                if v.len() == 1 {
+                    v.move_iter().next().unwrap()
+                } else {
+                    fail!(err)
+                }
+            }
             _ => fail!(err)
         }
     }

src/test/compile-fail/borrowck-move-out-of-vec-tail.rs

@@ -21,6 +21,7 @@ pub fn main() {
         Foo { string: ~"bar" },
         Foo { string: ~"baz" }
     ];
+    let x: &[Foo] = x;
     match x {
         [_, ..tail] => {
             match tail {

src/test/compile-fail/borrowck-vec-pattern-element-loan.rs

@@ -10,8 +10,9 @@
 
 fn a() -> &[int] {
     let vec = ~[1, 2, 3, 4];
+    let vec: &[int] = vec; //~ ERROR does not live long enough
     let tail = match vec {
-        [_, ..tail] => tail, //~ ERROR does not live long enough
+        [_, ..tail] => tail,
         _ => fail!("a")
     };
     tail
@@ -19,8 +20,9 @@ fn a() -> &[int] {
 
 fn b() -> &[int] {
     let vec = ~[1, 2, 3, 4];
+    let vec: &[int] = vec; //~ ERROR does not live long enough
     let init = match vec {
-        [..init, _] => init, //~ ERROR does not live long enough
+        [..init, _] => init,
         _ => fail!("b")
     };
     init
@@ -28,8 +30,9 @@ fn b() -> &[int] {
 
 fn c() -> &[int] {
     let vec = ~[1, 2, 3, 4];
+    let vec: &[int] = vec; //~ ERROR does not live long enough
     let slice = match vec {
-        [_, ..slice, _] => slice, //~ ERROR does not live long enough
+        [_, ..slice, _] => slice,
         _ => fail!("c")
     };
     slice

src/test/compile-fail/borrowck-vec-pattern-loan-from-mut.rs

@@ -10,7 +10,8 @@
 
 fn a() {
     let mut v = ~[1, 2, 3];
-    match v {
+    let vb: &mut [int] = v;
+    match vb {
         [_a, ..tail] => {
             v.push(tail[0] + tail[1]); //~ ERROR cannot borrow
         }

src/test/compile-fail/borrowck-vec-pattern-nesting.rs

@@ -9,17 +9,17 @@
 // except according to those terms.
 
 fn a() {
-    let mut vec = ~[~1, ~2, ~3];
+    let mut vec = [~1, ~2, ~3];
     match vec {
-        [~ref _a] => {
+        [~ref _a, _, _] => {
             vec[0] = ~4; //~ ERROR cannot assign
         }
-        _ => fail!("foo")
     }
 }
 
 fn b() {
     let mut vec = ~[~1, ~2, ~3];
+    let vec: &mut [~int] = vec;
     match vec {
         [.._b] => {
             vec[0] = ~4; //~ ERROR cannot assign
@@ -29,6 +29,7 @@ fn b() {
 
 fn c() {
     let mut vec = ~[~1, ~2, ~3];
+    let vec: &mut [~int] = vec;
     match vec {
         [_a, .._b] => {
             //~^ ERROR cannot move out
@@ -41,27 +42,31 @@ fn c() {
         }
         _ => {}
     }
-    let a = vec[0]; //~ ERROR use of partially moved value: `vec`
+    let a = vec[0]; //~ ERROR cannot move out
 }
 
 fn d() {
     let mut vec = ~[~1, ~2, ~3];
+    let vec: &mut [~int] = vec;
     match vec {
         [.._a, _b] => {
             //~^ ERROR cannot move out
         }
         _ => {}
     }
-    let a = vec[0]; //~ ERROR use of partially moved value: `vec`
+    let a = vec[0]; //~ ERROR cannot move out
 }
 
 fn e() {
     let mut vec = ~[~1, ~2, ~3];
+    let vec: &mut [~int] = vec;
     match vec {
-        [_a, _b, _c] => {}
+        [_a, _b, _c] => {}  //~ ERROR cannot move out
+        //~^ ERROR cannot move out
+        //~^^ ERROR cannot move out
         _ => {}
     }
-    let a = vec[0]; //~ ERROR use of partially moved value: `vec`
+    let a = vec[0]; //~ ERROR cannot move out
 }
 
 fn main() {}

src/test/compile-fail/borrowck-vec-pattern-tail-element-loan.rs

@@ -10,8 +10,9 @@
 
 fn a() -> &int {
     let vec = ~[1, 2, 3, 4];
+    let vec: &[int] = vec; //~ ERROR `vec[..]` does not live long enough
     let tail = match vec {
-        [_a, ..tail] => &tail[0], //~ ERROR `vec[..]` does not live long enough
+        [_a, ..tail] => &tail[0],
         _ => fail!("foo")
     };
     tail

src/test/compile-fail/match-vec-unreachable.rs

@@ -10,19 +10,24 @@
 
 fn main() {
     let x: ~[(int, int)] = ~[];
+    let x: &[(int, int)] = x;
     match x {
         [a, (2, 3), _] => (),
         [(1, 2), (2, 3), b] => (), //~ ERROR unreachable pattern
         _ => ()
     }
 
-    match ~[~"foo", ~"bar", ~"baz"] {
+    let x: ~[~str] = ~[~"foo", ~"bar", ~"baz"];
+    let x: &[~str] = x;
+    match x {
         [a, _, _, ..] => { println!("{}", a); }
         [~"foo", ~"bar", ~"baz", ~"foo", ~"bar"] => { } //~ ERROR unreachable pattern
         _ => { }
     }
 
-    match ~['a', 'b', 'c'] {
+    let x: ~[char] = ~['a', 'b', 'c'];
+    let x: &[char] = x;
+    match x {
         ['a', 'b', 'c', .._tail] => {}
         ['a', 'b', 'c'] => {} //~ ERROR unreachable pattern
         _ => {}

src/test/compile-fail/non-exhaustive-match.rs

@@ -35,23 +35,31 @@ fn main() {
       (_, a) => {}
       (b, b) => {}
     }
-    match ~[Some(42), None, Some(21)] {
+    let vec = ~[Some(42), None, Some(21)];
+    let vec: &[Option<int>] = vec;
+    match vec {
         //~^ ERROR non-exhaustive patterns: vectors of length 0 not covered
         [Some(..), None, ..tail] => {}
         [Some(..), Some(..), ..tail] => {}
         [None] => {}
     }
-    match ~[1] {
+    let vec = ~[1];
+    let vec: &[int] = vec;
+    match vec {
         [_, ..tail] => (),
         [] => ()
     }
-    match ~[0.5] { //~ ERROR non-exhaustive patterns: vectors of length 4 not covered
+    let vec = ~[0.5];
+    let vec: &[f32] = vec;
+    match vec { //~ ERROR non-exhaustive patterns: vectors of length 4 not covered
         [0.1, 0.2, 0.3] => (),
         [0.1, 0.2] => (),
         [0.1] => (),
         [] => ()
     }
-    match ~[Some(42), None, Some(21)] {
+    let vec = ~[Some(42), None, Some(21)];
+    let vec: &[Option<int>] = vec;
+    match vec {
         [Some(..), None, ..tail] => {}
         [Some(..), Some(..), ..tail] => {}
         [None, None, ..tail] => {}

src/test/run-pass/vec-matching-autoslice.rs

@@ -9,24 +9,22 @@
 // except according to those terms.
 
 pub fn main() {
-    let x = ~[1, 2, 3];
+    let x = [1, 2, 3];
     match x {
-        [2, ..] => fail!(),
+        [2, _, _] => fail!(),
-        [1, ..tail] => {
+        [1, a, b] => {
-            assert_eq!(tail, [2, 3]);
+            assert_eq!([a, b], [2, 3]);
         }
-        [_] => fail!(),
+        [_, _, _] => fail!(),
-        [] => fail!()
     }
 
-    let y = (~[(1, true), (2, false)], 0.5);
+    let y = ([(1, true), (2, false)], 0.5);
     match y {
-        ([_, _, _], 0.5) => fail!(),
+        ([(1, a), (b, false)], _) => {
-        ([(1, a), (b, false), ..tail], _) => {
             assert_eq!(a, true);
             assert_eq!(b, 2);
-            assert!(tail.is_empty());
         }
-        ([.._tail], _) => fail!()
+        ([_, _], 0.5) => fail!(),
+        ([_, _], _) => fail!(),
     }
 }

src/test/run-pass/vec-matching.rs

@@ -9,28 +9,22 @@
 // except according to those terms.
 
 fn a() {
-    let x = ~[1];
+    let x = [1];
     match x {
-        [_, _, _, _, _, ..] => fail!(),
-        [.., _, _, _, _] => fail!(),
-        [_, .., _, _] => fail!(),
-        [_, _] => fail!(),
         [a] => {
             assert_eq!(a, 1);
         }
-        [] => fail!()
     }
 }
 
 fn b() {
-    let x = ~[1, 2, 3];
+    let x = [1, 2, 3];
     match x {
         [a, b, ..c] => {
             assert_eq!(a, 1);
             assert_eq!(b, 2);
             assert_eq!(c, &[3]);
         }
-        _ => fail!()
     }
     match x {
         [..a, b, c] => {
@@ -38,7 +32,6 @@ fn b() {
             assert_eq!(b, 2);
             assert_eq!(c, 3);
         }
-        _ => fail!()
     }
     match x {
         [a, ..b, c] => {
@@ -46,7 +39,6 @@ fn b() {
             assert_eq!(b, &[2]);
             assert_eq!(c, 3);
         }
-        _ => fail!()
     }
     match x {
         [a, b, c] => {
@@ -54,7 +46,6 @@ fn b() {
             assert_eq!(b, 2);
             assert_eq!(c, 3);
         }
-        _ => fail!()
     }
 }
 

src/test/run-pass/vec-tail-matching.rs

@@ -14,7 +14,7 @@ struct Foo {
 }
 
 pub fn main() {
-    let x = ~[
+    let x = [
         Foo { string: ~"foo" },
         Foo { string: ~"bar" },
         Foo { string: ~"baz" }
@@ -39,8 +39,5 @@ pub fn main() {
                 }
             }
         }
-        _ => {
-            unreachable!();
-        }
     }
 }