std: rename fmt::Default to `Show`.

This is a better name with which to have a #[deriving] mode.

Decision in:
https://github.com/mozilla/rust/wiki/Meeting-weekly-2014-01-28

src/librustdoc/html/escape.rs

@@ -19,7 +19,7 @@
 /// string when passed to a format string.
 pub struct Escape<'a>(&'a str);
 
-impl<'a> fmt::Default for Escape<'a> {
+impl<'a> fmt::Show for Escape<'a> {
     fn fmt(s: &Escape<'a>, fmt: &mut fmt::Formatter) {
         // Because the internet is always right, turns out there's not that many
         // characters to escape: http://stackoverflow.com/questions/7381974

src/librustdoc/html/format.rs

@@ -10,7 +10,7 @@
 
 //! HTML formatting module
 //!
-//! This module contains a large number of `fmt::Default` implementations for
+//! This module contains a large number of `fmt::Show` implementations for
 //! various types in `rustdoc::clean`. These implementations all currently
 //! assume that HTML output is desired, although it may be possible to redesign
 //! them in the future to instead emit any format desired.
@@ -47,7 +47,7 @@ pub fn get(&self) -> ast::Purity {
     }
 }
 
-impl fmt::Default for clean::Generics {
+impl fmt::Show for clean::Generics {
     fn fmt(g: &clean::Generics, f: &mut fmt::Formatter) {
         if g.lifetimes.len() == 0 && g.type_params.len() == 0 { return }
         f.buf.write("<".as_bytes());
@@ -77,14 +77,14 @@ fn fmt(g: &clean::Generics, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::Lifetime {
+impl fmt::Show for clean::Lifetime {
     fn fmt(l: &clean::Lifetime, f: &mut fmt::Formatter) {
         f.buf.write("'".as_bytes());
         f.buf.write(l.get_ref().as_bytes());
     }
 }
 
-impl fmt::Default for clean::TyParamBound {
+impl fmt::Show for clean::TyParamBound {
     fn fmt(bound: &clean::TyParamBound, f: &mut fmt::Formatter) {
         match *bound {
             clean::RegionBound => {
@@ -97,7 +97,7 @@ fn fmt(bound: &clean::TyParamBound, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::Path {
+impl fmt::Show for clean::Path {
     fn fmt(path: &clean::Path, f: &mut fmt::Formatter) {
         if path.global { f.buf.write("::".as_bytes()) }
         for (i, seg) in path.segments.iter().enumerate() {
@@ -269,7 +269,7 @@ fn typarams(w: &mut io::Writer, typarams: &Option<~[clean::TyParamBound]>) {
     }
 }
 
-impl fmt::Default for clean::Type {
+impl fmt::Show for clean::Type {
     fn fmt(g: &clean::Type, f: &mut fmt::Formatter) {
         match *g {
             clean::TyParamBinder(id) | clean::Generic(id) => {
@@ -374,7 +374,7 @@ fn fmt(g: &clean::Type, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::FnDecl {
+impl fmt::Show for clean::FnDecl {
     fn fmt(d: &clean::FnDecl, f: &mut fmt::Formatter) {
         write!(f.buf, "({args}){arrow, select, yes{ -&gt; {ret}} other{}}",
                args = d.inputs,
@@ -383,7 +383,7 @@ fn fmt(d: &clean::FnDecl, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for ~[clean::Argument] {
+impl fmt::Show for ~[clean::Argument] {
     fn fmt(inputs: &~[clean::Argument], f: &mut fmt::Formatter) {
         let mut args = ~"";
         for (i, input) in inputs.iter().enumerate() {
@@ -397,7 +397,7 @@ fn fmt(inputs: &~[clean::Argument], f: &mut fmt::Formatter) {
     }
 }
 
-impl<'a> fmt::Default for Method<'a> {
+impl<'a> fmt::Show for Method<'a> {
     fn fmt(m: &Method<'a>, f: &mut fmt::Formatter) {
         let Method(selfty, d) = *m;
         let mut args = ~"";
@@ -433,7 +433,7 @@ fn fmt(m: &Method<'a>, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for VisSpace {
+impl fmt::Show for VisSpace {
     fn fmt(v: &VisSpace, f: &mut fmt::Formatter) {
         match v.get() {
             Some(ast::Public) => { write!(f.buf, "pub "); }
@@ -443,7 +443,7 @@ fn fmt(v: &VisSpace, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for PuritySpace {
+impl fmt::Show for PuritySpace {
     fn fmt(p: &PuritySpace, f: &mut fmt::Formatter) {
         match p.get() {
             ast::UnsafeFn => write!(f.buf, "unsafe "),
@@ -453,7 +453,7 @@ fn fmt(p: &PuritySpace, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::ViewPath {
+impl fmt::Show for clean::ViewPath {
     fn fmt(v: &clean::ViewPath, f: &mut fmt::Formatter) {
         match *v {
             clean::SimpleImport(ref name, ref src) => {
@@ -478,7 +478,7 @@ fn fmt(v: &clean::ViewPath, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::ImportSource {
+impl fmt::Show for clean::ImportSource {
     fn fmt(v: &clean::ImportSource, f: &mut fmt::Formatter) {
         match v.did {
             // FIXME: shouldn't be restricted to just local imports
@@ -495,7 +495,7 @@ fn fmt(v: &clean::ImportSource, f: &mut fmt::Formatter) {
     }
 }
 
-impl fmt::Default for clean::ViewListIdent {
+impl fmt::Show for clean::ViewListIdent {
     fn fmt(v: &clean::ViewListIdent, f: &mut fmt::Formatter) {
         match v.source {
             // FIXME: shouldn't be limited to just local imports

src/librustdoc/html/layout.rs

@@ -24,7 +24,7 @@ pub struct Page<'a> {
     root_path: &'a str,
 }
 
-pub fn render<T: fmt::Default, S: fmt::Default>(
+pub fn render<T: fmt::Show, S: fmt::Show>(
     dst: &mut io::Writer, layout: &Layout, page: &Page, sidebar: &S, t: &T)
 {
     write!(dst,

src/librustdoc/html/markdown.rs

@@ -14,7 +14,7 @@
 //! (bundled into the rust runtime). This module self-contains the C bindings
 //! and necessary legwork to render markdown, and exposes all of the
 //! functionality through a unit-struct, `Markdown`, which has an implementation
-//! of `fmt::Default`. Example usage:
+//! of `fmt::Show`. Example usage:
 //!
 //! ```rust,ignore
 //! use rustdoc::html::markdown::Markdown;
@@ -32,7 +32,7 @@
 use std::unstable::intrinsics;
 use std::vec;
 
-/// A unit struct which has the `fmt::Default` trait implemented. When
+/// A unit struct which has the `fmt::Show` trait implemented. When
 /// formatted, this struct will emit the HTML corresponding to the rendered
 /// version of the contained markdown string.
 pub struct Markdown<'a>(&'a str);
@@ -209,7 +209,7 @@ pub fn find_testable_code(doc: &str, tests: &mut ::test::Collector) {
     }
 }
 
-impl<'a> fmt::Default for Markdown<'a> {
+impl<'a> fmt::Show for Markdown<'a> {
     fn fmt(md: &Markdown<'a>, fmt: &mut fmt::Formatter) {
         let Markdown(md) = *md;
         // This is actually common enough to special-case

src/librustdoc/html/render.rs

@@ -801,7 +801,7 @@ fn ismodule(&self) -> bool {
     }
 }
 
-impl<'a> fmt::Default for Item<'a> {
+impl<'a> fmt::Show for Item<'a> {
     fn fmt(it: &Item<'a>, fmt: &mut fmt::Formatter) {
         match attr::find_stability(it.item.attrs.iter()) {
             Some(ref stability) => {
@@ -990,7 +990,7 @@ fn cmp(i1: &clean::Item, i2: &clean::Item, idx1: uint, idx2: uint) -> Ordering {
         match myitem.inner {
             clean::StaticItem(ref s) | clean::ForeignStaticItem(ref s) => {
                 struct Initializer<'a>(&'a str);
-                impl<'a> fmt::Default for Initializer<'a> {
+                impl<'a> fmt::Show for Initializer<'a> {
                     fn fmt(s: &Initializer<'a>, f: &mut fmt::Formatter) {
                         let Initializer(s) = *s;
                         if s.len() == 0 { return; }
@@ -1491,7 +1491,7 @@ fn item_typedef(w: &mut Writer, it: &clean::Item, t: &clean::Typedef) {
     document(w, it);
 }
 
-impl<'a> fmt::Default for Sidebar<'a> {
+impl<'a> fmt::Show for Sidebar<'a> {
     fn fmt(s: &Sidebar<'a>, fmt: &mut fmt::Formatter) {
         let cx = s.cx;
         let it = s.item;
@@ -1556,7 +1556,7 @@ fn build_sidebar(m: &clean::Module) -> HashMap<~str, ~[~str]> {
     return map;
 }
 
-impl<'a> fmt::Default for Source<'a> {
+impl<'a> fmt::Show for Source<'a> {
     fn fmt(s: &Source<'a>, fmt: &mut fmt::Formatter) {
         let Source(s) = *s;
         let lines = s.lines().len();

src/libstd/fmt/mod.rs

@@ -149,13 +149,13 @@
 * `f` ⇒ `Float`
 * `e` ⇒ `LowerExp`
 * `E` ⇒ `UpperExp`
-* *nothing* ⇒ `Default`
+* *nothing* ⇒ `Show`
 
 What this means is that any type of argument which implements the
 `std::fmt::Binary` trait can then be formatted with `{:t}`. Implementations are
 provided for these traits for a number of primitive types by the standard
 library as well. If no format is specified (as in `{}` or `{:6}`), then the
-format trait used is the `Default` trait. This is one of the more commonly
+format trait used is the `Show` trait. This is one of the more commonly
 implemented traits when formatting a custom type.
 
 When implementing a format trait for your own time, you will have to implement a
@@ -186,7 +186,7 @@ struct Vector2D {
     y: int,
 }
 
-impl fmt::Default for Vector2D {
+impl fmt::Show for Vector2D {
     fn fmt(obj: &Vector2D, f: &mut fmt::Formatter) {
         // The `f.buf` value is of the type `&mut io::Writer`, which is what th
         // write! macro is expecting. Note that this formatting ignores the
@@ -468,6 +468,7 @@ fn main() {
 
 */
 
+#[cfg(not(stage0))]
 use prelude::*;
 
 use cast;
@@ -479,6 +480,24 @@ fn main() {
 use util;
 use vec;
 
+// SNAP b6400f9 this is just because the `prelude::*` import above
+// includes default::Default, so the reexport doesn't work.
+#[cfg(stage0)]
+pub use Default = fmt::Show; // export required for `format!()` etc.
+
+#[cfg(stage0)]
+use container::Container;
+#[cfg(stage0)]
+use iter::{Iterator, range};
+#[cfg(stage0)]
+use option::{Option,Some,None};
+#[cfg(stage0)]
+use vec::ImmutableVector;
+#[cfg(stage0)]
+use str::StrSlice;
+#[cfg(stage0)]
+use num::Signed;
+
 pub mod parse;
 pub mod rt;
 
@@ -542,7 +561,7 @@ pub struct Arguments<'a> {
 /// to this trait. There is not an explicit way of selecting this trait to be
 /// used for formatting, it is only if no other format is specified.
 #[allow(missing_doc)]
-pub trait Default { fn fmt(&Self, &mut Formatter); }
+pub trait Show { fn fmt(&Self, &mut Formatter); }
 
 /// Format trait for the `b` character
 #[allow(missing_doc)]
@@ -1148,10 +1167,10 @@ impl<T> Pointer for *mut T {
     fn fmt(t: &*mut T, f: &mut Formatter) { Pointer::fmt(&(*t as *T), f) }
 }
 
-// Implementation of Default for various core types
+// Implementation of Show for various core types
 
 macro_rules! delegate(($ty:ty to $other:ident) => {
-    impl<'a> Default for $ty {
+    impl<'a> Show for $ty {
         fn fmt(me: &$ty, f: &mut Formatter) {
             $other::fmt(me, f)
         }
@@ -1174,10 +1193,10 @@ fn fmt(me: &$ty, f: &mut Formatter) {
 delegate!(f32 to Float)
 delegate!(f64 to Float)
 
-impl<T> Default for *T {
+impl<T> Show for *T {
     fn fmt(me: &*T, f: &mut Formatter) { Pointer::fmt(me, f) }
 }
-impl<T> Default for *mut T {
+impl<T> Show for *mut T {
     fn fmt(me: &*mut T, f: &mut Formatter) { Pointer::fmt(me, f) }
 }
 

src/libstd/io/process.rs

@@ -91,7 +91,7 @@ pub enum ProcessExit {
     ExitSignal(int),
 }
 
-impl fmt::Default for ProcessExit {
+impl fmt::Show for ProcessExit {
     /// Format a ProcessExit enum, to nicely present the information.
     fn fmt(obj: &ProcessExit, f: &mut fmt::Formatter) {
         match *obj {

src/libstd/option.rs

@@ -380,7 +380,7 @@ pub fn unwrap_or_default(self) -> T {
 // Trait implementations
 /////////////////////////////////////////////////////////////////////////////
 
-impl<T: fmt::Default> fmt::Default for Option<T> {
+impl<T: fmt::Show> fmt::Show for Option<T> {
     #[inline]
     fn fmt(s: &Option<T>, f: &mut fmt::Formatter) {
         match *s {

src/libstd/os.rs

@@ -928,7 +928,7 @@ pub enum MapError {
     ErrMapViewOfFile(uint)
 }
 
-impl fmt::Default for MapError {
+impl fmt::Show for MapError {
     fn fmt(val: &MapError, out: &mut fmt::Formatter) {
         let str = match *val {
             ErrFdNotAvail => "fd not available for reading or writing",

src/libstd/path/mod.rs

@@ -198,14 +198,14 @@ fn as_str<'a>(&'a self) -> Option<&'a str> {
     /// Converts the Path into an owned byte vector
     fn into_vec(self) -> ~[u8];
 
-    /// Returns an object that implements `fmt::Default` for printing paths
+    /// Returns an object that implements `Show` for printing paths
     ///
     /// This will print the equivalent of `to_display_str()` when used with a {} format parameter.
     fn display<'a>(&'a self) -> Display<'a, Self> {
         Display{ path: self, filename: false }
     }
 
-    /// Returns an object that implements `fmt::Default` for printing filenames
+    /// Returns an object that implements `Show` for printing filenames
     ///
     /// This will print the equivalent of `to_filename_display_str()` when used with a {}
     /// format parameter. If there is no filename, nothing will be printed.
@@ -532,7 +532,7 @@ pub struct Display<'a, P> {
     priv filename: bool
 }
 
-impl<'a, P: GenericPath> fmt::Default for Display<'a, P> {
+impl<'a, P: GenericPath> fmt::Show for Display<'a, P> {
     fn fmt(d: &Display<P>, f: &mut fmt::Formatter) {
         d.with_str(|s| f.pad(s))
     }

src/libstd/result.rs

@@ -206,7 +206,7 @@ pub fn unwrap_err(self) -> E {
 // Trait implementations
 /////////////////////////////////////////////////////////////////////////////
 
-impl<T: fmt::Default, E: fmt::Default> fmt::Default for Result<T, E> {
+impl<T: fmt::Show, E: fmt::Show> fmt::Show for Result<T, E> {
     #[inline]
     fn fmt(s: &Result<T, E>, f: &mut fmt::Formatter) {
         match *s {

src/libsyntax/ext/format.rs

@@ -704,22 +704,22 @@ fn format_arg(&self, sp: Span, argno: Position, arg: @ast::Expr)
 
         let fmt_trait = match *ty {
             Known(ref tyname) => {
-                match (*tyname).as_slice() {
-                    ""  => "Default",
-                    "?" => "Poly",
-                    "b" => "Bool",
-                    "c" => "Char",
-                    "d" | "i" => "Signed",
-                    "e" => "LowerExp",
-                    "E" => "UpperExp",
-                    "f" => "Float",
-                    "o" => "Octal",
-                    "p" => "Pointer",
-                    "s" => "String",
-                    "t" => "Binary",
-                    "u" => "Unsigned",
-                    "x" => "LowerHex",
-                    "X" => "UpperHex",
+                match tyname.as_slice() {
+                    ""  => "secret_show",
+                    "?" => "secret_poly",
+                    "b" => "secret_bool",
+                    "c" => "secret_char",
+                    "d" | "i" => "secret_signed",
+                    "e" => "secret_lower_exp",
+                    "E" => "secret_upper_exp",
+                    "f" => "secret_float",
+                    "o" => "secret_octal",
+                    "p" => "secret_pointer",
+                    "s" => "secret_string",
+                    "t" => "secret_binary",
+                    "u" => "secret_unsigned",
+                    "x" => "secret_lower_hex",
+                    "X" => "secret_upper_hex",
                     _ => {
                         self.ecx.span_err(sp,
                                           format!("unknown format trait `{}`",

src/libsyntax/parse/token.rs

@@ -587,7 +587,7 @@ fn container_as_bytes<'a>(&'a self) -> &'a [u8] {
     }
 }
 
-impl fmt::Default for InternedString {
+impl fmt::Show for InternedString {
     fn fmt(obj: &InternedString, f: &mut fmt::Formatter) {
         write!(f.buf, "{}", obj.string.as_slice());
     }

src/test/run-pass/logging-only-prints-once.rs

@@ -16,7 +16,7 @@
 
 struct Foo(Cell<int>);
 
-impl fmt::Default for Foo {
+impl fmt::Show for Foo {
     fn fmt(f: &Foo, _fmt: &mut fmt::Formatter) {
         let Foo(ref f) = *f;
         assert!(f.get() == 0);