auto merge of #9115 : erickt/rust/master, r=erickt

This is a series of patches to modernize option and result. The highlights are:

* rename `.unwrap_or_default(value)` and etc to `.unwrap_or(value)`
* add `.unwrap_or_default()` that uses the `Default` trait
* add `Default` implementations for vecs, HashMap, Option
* add  `Option.and(T) -> Option<T>`, `Option.and_then(&fn() -> Option<T>) -> Option<T>`, `Option.or(T) -> Option<T>`, and `Option.or_else(&fn() -> Option<T>) -> Option<T>`
* add `option::ToOption`, `option::IntoOption`, `option::AsOption`, `result::ToResult`, `result::IntoResult`, `result::AsResult`, `either::ToEither`, and `either::IntoEither`, `either::AsEither`
* renamed `Option::chain*` and `Result::chain*` to `and_then` and `or_else` to avoid the eventual collision with `Iterator.chain`.
* Added a bunch of impls of `Default`
* Added a `#[deriving(Default)]` syntax extension
* Removed impls of `Zero` for `Option<T>` and vecs.

doc/rust.md

@@ -1717,7 +1717,8 @@ Supported traits for `deriving` are:
 * `Clone` and `DeepClone`, to perform (deep) copies.
 * `IterBytes`, to iterate over the bytes in a data type.
 * `Rand`, to create a random instance of a data type.
-* `Zero`, to create an zero (or empty) instance of a data type.
+* `Default`, to create an empty instance of a data type.
+* `Zero`, to create an zero instance of a numeric data type.
 * `ToStr`, to convert to a string. For a type with this instance,
   `obj.to_str()` has similar output as `fmt!("%?", obj)`, but it differs in that
   each constituent field of the type must also implement `ToStr` and will have

doc/tutorial.md

@@ -2249,7 +2249,7 @@ enum ABC { A, B, C }
 
 The full list of derivable traits is `Eq`, `TotalEq`, `Ord`,
 `TotalOrd`, `Encodable` `Decodable`, `Clone`, `DeepClone`,
-`IterBytes`, `Rand`, `Zero`, and `ToStr`.
+`IterBytes`, `Rand`, `Default`, `Zero`, and `ToStr`.
 
 # Crates and the module system
 

src/compiletest/compiletest.rs

@@ -309,7 +309,7 @@ pub fn make_test_name(config: &config, testfile: &Path) -> test::TestName {
         let filename = path.filename();
         let p = path.pop();
         let dir = p.filename();
-        fmt!("%s/%s", dir.unwrap_or_default(""), filename.unwrap_or_default(""))
+        fmt!("%s/%s", dir.unwrap_or(""), filename.unwrap_or(""))
     }
 
     test::DynTestName(fmt!("[%s] %s",

src/libextra/glob.rs

@@ -137,7 +137,17 @@ fn list_dir_sorted(path: &Path) -> ~[Path] {
 /**
  * A compiled Unix shell style pattern.
  */
-#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes, Zero)]
+#[cfg(stage0)]
+#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes)]
+pub struct Pattern {
+    priv tokens: ~[PatternToken]
+}
+
+/**
+ * A compiled Unix shell style pattern.
+ */
+#[cfg(not(stage0))]
+#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes, Default)]
 pub struct Pattern {
     priv tokens: ~[PatternToken]
 }
@@ -312,7 +322,7 @@ impl Pattern {
         let require_literal = |c| {
             (options.require_literal_separator && is_sep(c)) ||
             (options.require_literal_leading_dot && c == '.'
-             && is_sep(prev_char.unwrap_or_default('/')))
+             && is_sep(prev_char.unwrap_or('/')))
         };
 
         for (ti, token) in self.tokens.slice_from(i).iter().enumerate() {
@@ -458,7 +468,37 @@ fn is_sep(c: char) -> bool {
 /**
  * Configuration options to modify the behaviour of `Pattern::matches_with(..)`
  */
-#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes, Zero)]
+#[cfg(stage0)]
+#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes)]
+pub struct MatchOptions {
+
+    /**
+     * Whether or not patterns should be matched in a case-sensitive manner. This
+     * currently only considers upper/lower case relationships between ASCII characters,
+     * but in future this might be extended to work with Unicode.
+     */
+    case_sensitive: bool,
+
+    /**
+     * If this is true then path-component separator characters (e.g. `/` on Posix)
+     * must be matched by a literal `/`, rather than by `*` or `?` or `[...]`
+     */
+    require_literal_separator: bool,
+
+    /**
+     * If this is true then paths that contain components that start with a `.` will
+     * not match unless the `.` appears literally in the pattern: `*`, `?` or `[...]`
+     * will not match. This is useful because such files are conventionally considered
+     * hidden on Unix systems and it might be desirable to skip them when listing files.
+     */
+    require_literal_leading_dot: bool
+}
+
+/**
+ * Configuration options to modify the behaviour of `Pattern::matches_with(..)`
+ */
+#[cfg(not(stage0))]
+#[deriving(Clone, Eq, TotalEq, Ord, TotalOrd, IterBytes, Default)]
 pub struct MatchOptions {
 
     /**

src/libextra/num/bigint.rs

@@ -635,7 +635,7 @@ impl BigUint {
 
     // Converts this BigUint into an int, unless it would overflow.
     pub fn to_int_opt(&self) -> Option<int> {
-        self.to_uint_opt().chain(|n| {
+        self.to_uint_opt().and_then(|n| {
             // If top bit of uint is set, it's too large to convert to
             // int.
             if (n >> (2*BigDigit::bits - 1) != 0) {
@@ -1221,7 +1221,7 @@ impl BigInt {
         match self.sign {
             Plus  => self.data.to_int_opt(),
             Zero  => Some(0),
-            Minus => self.data.to_uint_opt().chain(|n| {
+            Minus => self.data.to_uint_opt().and_then(|n| {
                 let m: uint = 1 << (2*BigDigit::bits-1);
                 if (n > m) {
                     None

src/libextra/num/rational.rs

@@ -273,9 +273,9 @@ impl<T: FromStr + Clone + Integer + Ord>
             return None
         }
         let a_option: Option<T> = FromStr::from_str(split[0]);
-        do a_option.chain |a| {
+        do a_option.and_then |a| {
             let b_option: Option<T> = FromStr::from_str(split[1]);
-            do b_option.chain |b| {
+            do b_option.and_then |b| {
                 Some(Ratio::new(a.clone(), b.clone()))
             }
         }
@@ -291,10 +291,10 @@ impl<T: FromStrRadix + Clone + Integer + Ord>
         } else {
             let a_option: Option<T> = FromStrRadix::from_str_radix(split[0],
                                                                    radix);
-            do a_option.chain |a| {
+            do a_option.and_then |a| {
                 let b_option: Option<T> =
                     FromStrRadix::from_str_radix(split[1], radix);
-                do b_option.chain |b| {
+                do b_option.and_then |b| {
                     Some(Ratio::new(a.clone(), b.clone()))
                 }
             }

src/libextra/time.rs

@@ -442,21 +442,21 @@ fn do_strptime(s: &str, format: &str) -> Result<Tm, ~str> {
           },
           'c' => {
             parse_type(s, pos, 'a', &mut *tm)
-                .chain(|pos| parse_char(s, pos, ' '))
-                .chain(|pos| parse_type(s, pos, 'b', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ' '))
-                .chain(|pos| parse_type(s, pos, 'e', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ' '))
-                .chain(|pos| parse_type(s, pos, 'T', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ' '))
-                .chain(|pos| parse_type(s, pos, 'Y', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ' '))
+                .and_then(|pos| parse_type(s, pos, 'b', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ' '))
+                .and_then(|pos| parse_type(s, pos, 'e', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ' '))
+                .and_then(|pos| parse_type(s, pos, 'T', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ' '))
+                .and_then(|pos| parse_type(s, pos, 'Y', &mut *tm))
           }
           'D' | 'x' => {
             parse_type(s, pos, 'm', &mut *tm)
-                .chain(|pos| parse_char(s, pos, '/'))
-                .chain(|pos| parse_type(s, pos, 'd', &mut *tm))
-                .chain(|pos| parse_char(s, pos, '/'))
-                .chain(|pos| parse_type(s, pos, 'y', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, '/'))
+                .and_then(|pos| parse_type(s, pos, 'd', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, '/'))
+                .and_then(|pos| parse_type(s, pos, 'y', &mut *tm))
           }
           'd' => match match_digits_in_range(s, pos, 2u, false, 1_i32,
                                              31_i32) {
@@ -475,10 +475,10 @@ fn do_strptime(s: &str, format: &str) -> Result<Tm, ~str> {
           }
           'F' => {
             parse_type(s, pos, 'Y', &mut *tm)
-                .chain(|pos| parse_char(s, pos, '-'))
-                .chain(|pos| parse_type(s, pos, 'm', &mut *tm))
-                .chain(|pos| parse_char(s, pos, '-'))
-                .chain(|pos| parse_type(s, pos, 'd', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, '-'))
+                .and_then(|pos| parse_type(s, pos, 'm', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, '-'))
+                .and_then(|pos| parse_type(s, pos, 'd', &mut *tm))
           }
           'H' => {
             match match_digits_in_range(s, pos, 2u, false, 0_i32, 23_i32) {
@@ -553,17 +553,17 @@ fn do_strptime(s: &str, format: &str) -> Result<Tm, ~str> {
           },
           'R' => {
             parse_type(s, pos, 'H', &mut *tm)
-                .chain(|pos| parse_char(s, pos, ':'))
-                .chain(|pos| parse_type(s, pos, 'M', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ':'))
+                .and_then(|pos| parse_type(s, pos, 'M', &mut *tm))
           }
           'r' => {
             parse_type(s, pos, 'I', &mut *tm)
-                .chain(|pos| parse_char(s, pos, ':'))
-                .chain(|pos| parse_type(s, pos, 'M', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ':'))
-                .chain(|pos| parse_type(s, pos, 'S', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ' '))
-                .chain(|pos| parse_type(s, pos, 'p', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ':'))
+                .and_then(|pos| parse_type(s, pos, 'M', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ':'))
+                .and_then(|pos| parse_type(s, pos, 'S', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ' '))
+                .and_then(|pos| parse_type(s, pos, 'p', &mut *tm))
           }
           'S' => {
             match match_digits_in_range(s, pos, 2u, false, 0_i32, 60_i32) {
@@ -578,10 +578,10 @@ fn do_strptime(s: &str, format: &str) -> Result<Tm, ~str> {
           //'s' {}
           'T' | 'X' => {
             parse_type(s, pos, 'H', &mut *tm)
-                .chain(|pos| parse_char(s, pos, ':'))
-                .chain(|pos| parse_type(s, pos, 'M', &mut *tm))
-                .chain(|pos| parse_char(s, pos, ':'))
-                .chain(|pos| parse_type(s, pos, 'S', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ':'))
+                .and_then(|pos| parse_type(s, pos, 'M', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, ':'))
+                .and_then(|pos| parse_type(s, pos, 'S', &mut *tm))
           }
           't' => parse_char(s, pos, '\t'),
           'u' => {
@@ -596,10 +596,10 @@ fn do_strptime(s: &str, format: &str) -> Result<Tm, ~str> {
           }
           'v' => {
             parse_type(s, pos, 'e', &mut *tm)
-                .chain(|pos|  parse_char(s, pos, '-'))
-                .chain(|pos| parse_type(s, pos, 'b', &mut *tm))
-                .chain(|pos| parse_char(s, pos, '-'))
-                .chain(|pos| parse_type(s, pos, 'Y', &mut *tm))
+                .and_then(|pos|  parse_char(s, pos, '-'))
+                .and_then(|pos| parse_type(s, pos, 'b', &mut *tm))
+                .and_then(|pos| parse_char(s, pos, '-'))
+                .and_then(|pos| parse_type(s, pos, 'Y', &mut *tm))
           }
           //'W' {}
           'w' => {

src/libextra/uuid.rs

@@ -417,6 +417,13 @@ impl Uuid {
     }
 }
 
+impl Default for Uuid {
+    /// Returns the nil UUID, which is all zeroes
+    fn default() -> Uuid {
+        Uuid::new_nil()
+    }
+}
+
 impl Zero for Uuid {
     /// Returns the nil UUID, which is all zeroes
     fn zero() -> Uuid {

src/librustc/driver/driver.rs

@@ -681,9 +681,9 @@ pub fn build_session_options(binary: @str,
             link::output_type_bitcode
         } else { link::output_type_exe };
     let sysroot_opt = getopts::opt_maybe_str(matches, "sysroot").map_move(|m| @Path(m));
-    let target = getopts::opt_maybe_str(matches, "target").unwrap_or_default(host_triple());
-    let target_cpu = getopts::opt_maybe_str(matches, "target-cpu").unwrap_or_default(~"generic");
-    let target_feature = getopts::opt_maybe_str(matches, "target-feature").unwrap_or_default(~"");
+    let target = getopts::opt_maybe_str(matches, "target").unwrap_or(host_triple());
+    let target_cpu = getopts::opt_maybe_str(matches, "target-cpu").unwrap_or(~"generic");
+    let target_feature = getopts::opt_maybe_str(matches, "target-feature").unwrap_or(~"");
     let save_temps = getopts::opt_present(matches, "save-temps");
     let opt_level = {
         if (debugging_opts & session::no_opt) != 0 {
@@ -961,7 +961,7 @@ pub fn build_output_filenames(input: &input,
           if !linkage_metas.is_empty() {
               // But if a linkage meta is present, that overrides
               let maybe_name = linkage_metas.iter().find(|m| "name" == m.name());
-              match maybe_name.chain(|m| m.value_str()) {
+              match maybe_name.and_then(|m| m.value_str()) {
                   Some(s) => stem = s,
                   _ => ()
               }

src/librustc/front/config.rs

@@ -58,7 +58,7 @@ fn filter_view_item<'r>(cx: @Context, view_item: &'r ast::view_item)-> Option<&'
 
 fn fold_mod(cx: @Context, m: &ast::_mod, fld: @fold::ast_fold) -> ast::_mod {
     let filtered_items = do  m.items.iter().filter_map |a| {
-        filter_item(cx, *a).chain(|x| fld.fold_item(x))
+        filter_item(cx, *a).and_then(|x| fld.fold_item(x))
     }.collect();
     let filtered_view_items = do m.view_items.iter().filter_map |a| {
         do filter_view_item(cx, a).map_move |x| {
@@ -139,7 +139,7 @@ fn fold_block(
     fld: @fold::ast_fold
 ) -> ast::Block {
     let resulting_stmts = do b.stmts.iter().filter_map |a| {
-        filter_stmt(cx, *a).chain(|stmt| fld.fold_stmt(stmt))
+        filter_stmt(cx, *a).and_then(|stmt| fld.fold_stmt(stmt))
     }.collect();
     let filtered_view_items = do b.view_items.iter().filter_map |a| {
         filter_view_item(cx, a).map(|x| fld.fold_view_item(*x))

src/librustc/metadata/creader.rs

@@ -184,7 +184,7 @@ fn visit_item(e: &Env, i: @ast::item) {
             ast::named => {
                 let link_name = i.attrs.iter()
                     .find(|at| "link_name" == at.name())
-                    .chain(|at| at.value_str());
+                    .and_then(|at| at.value_str());
 
                 let foreign_name = match link_name {
                         Some(nn) => {

src/librustc/metadata/decoder.rs

@@ -210,7 +210,7 @@ fn each_reexport(d: ebml::Doc, f: &fn(ebml::Doc) -> bool) -> bool {
 }
 
 fn variant_disr_val(d: ebml::Doc) -> Option<ty::Disr> {
-    do reader::maybe_get_doc(d, tag_disr_val).chain |val_doc| {
+    do reader::maybe_get_doc(d, tag_disr_val).and_then |val_doc| {
         do reader::with_doc_data(val_doc) |data| { u64::parse_bytes(data, 10u) }
     }
 }

src/librustc/middle/privacy.rs

@@ -221,8 +221,7 @@ impl PrivacyVisitor {
         // If the method is a default method, we need to use the def_id of
         // the default implementation.
         // Having to do this this is really unfortunate.
-        let method_id = ty::method(self.tcx, method_id).provided_source
-            .unwrap_or_default(method_id);
+        let method_id = ty::method(self.tcx, method_id).provided_source.unwrap_or(method_id);
 
         if method_id.crate == LOCAL_CRATE {
             let is_private = self.method_is_private(span, method_id.node);

src/librustc/middle/trans/common.rs

@@ -505,7 +505,7 @@ impl get_node_info for ast::Block {
 
 impl get_node_info for Option<@ast::Expr> {
     fn info(&self) -> Option<NodeInfo> {
-        self.chain_ref(|s| s.info())
+        self.and_then_ref(|s| s.info())
     }
 }
 

src/librustc/middle/trans/value.rs

@@ -50,9 +50,9 @@ impl Value {
     /// must be the only user of this value, and there must not be any conditional
     /// branches between the store and the given block.
     pub fn get_dominating_store(self, bcx: @mut Block) -> Option<Value> {
-        match self.get_single_user().chain(|user| user.as_store_inst()) {
+        match self.get_single_user().and_then(|user| user.as_store_inst()) {
             Some(store) => {
-                do store.get_parent().chain |store_bb| {
+                do store.get_parent().and_then |store_bb| {
                     let mut bb = BasicBlock(bcx.llbb);
                     let mut ret = Some(store);
                     while *bb != *store_bb {
@@ -150,7 +150,7 @@ impl Iterator<Value> for UserIterator {
     fn next(&mut self) -> Option<Value> {
         let current = self.next;
 
-        self.next = do current.chain |u| { u.get_next_use() };
+        self.next = do current.and_then |u| { u.get_next_use() };
 
         do current.map |u| { u.get_user() }
     }

src/librustc/middle/typeck/astconv.rs

@@ -745,7 +745,7 @@ pub fn ty_of_closure<AC:AstConv,RS:RegionScope + Clone + 'static>(
                           RegionParamNames(bound_lifetime_names.clone()));
 
     let input_tys = do decl.inputs.iter().enumerate().map |(i, a)| {
-        let expected_arg_ty = do expected_sig.chain_ref |e| {
+        let expected_arg_ty = do expected_sig.and_then_ref |e| {
             // no guarantee that the correct number of expected args
             // were supplied
             if i < e.inputs.len() {Some(e.inputs[i])} else {None}

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

@@ -173,7 +173,7 @@ pub fn check_pat_variant(pcx: &pat_ctxt, pat: @ast::Pat, path: &ast::Path,
                     fcx.write_error(pat.id);
                     kind_name = "[error]";
                     arg_types = (*subpats).clone()
-                                          .unwrap_or_default(~[])
+                                          .unwrap_or_default()
                                           .map(|_| ty::mk_err());
                 }
             }
@@ -222,7 +222,7 @@ pub fn check_pat_variant(pcx: &pat_ctxt, pat: @ast::Pat, path: &ast::Path,
             fcx.write_error(pat.id);
             kind_name = "[error]";
             arg_types = (*subpats).clone()
-                                  .unwrap_or_default(~[])
+                                  .unwrap_or_default()
                                   .map(|_| ty::mk_err());
         }
     }