add libcore from 2016-04-11 nightly

1 files changed, 262 insertions, 0 deletions

diff --git a/libcore/fmt/num.rs b/libcore/fmt/num.rs
new file mode 100644
index 0000000..a944c99
--- /dev/null
+++ b/libcore/fmt/num.rs
@@ -0,0 +1,262 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Integer and floating-point number formatting
+
+#![allow(deprecated)]
+
+// FIXME: #6220 Implement floating point formatting
+
+use prelude::v1::*;
+
+use fmt;
+use num::Zero;
+use ops::{Div, Rem, Sub};
+use str;
+use slice;
+use ptr;
+use mem;
+
+#[doc(hidden)]
+trait Int: Zero + PartialEq + PartialOrd + Div<Output=Self> + Rem<Output=Self> +
+           Sub<Output=Self> + Copy {
+    fn from_u8(u: u8) -> Self;
+    fn to_u8(&self) -> u8;
+    fn to_u32(&self) -> u32;
+    fn to_u64(&self) -> u64;
+}
+
+macro_rules! doit {
+    ($($t:ident)*) => ($(impl Int for $t {
+        fn from_u8(u: u8) -> $t { u as $t }
+        fn to_u8(&self) -> u8 { *self as u8 }
+        fn to_u32(&self) -> u32 { *self as u32 }
+        fn to_u64(&self) -> u64 { *self as u64 }
+    })*)
+}
+doit! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
+
+/// A type that represents a specific radix
+#[doc(hidden)]
+trait GenericRadix {
+    /// The number of digits.
+    fn base(&self) -> u8;
+
+    /// A radix-specific prefix string.
+    fn prefix(&self) -> &'static str {
+        ""
+    }
+
+    /// Converts an integer to corresponding radix digit.
+    fn digit(&self, x: u8) -> u8;
+
+    /// Format an integer using the radix using a formatter.
+    fn fmt_int<T: Int>(&self, mut x: T, f: &mut fmt::Formatter) -> fmt::Result {
+        // The radix can be as low as 2, so we need a buffer of at least 64
+        // characters for a base 2 number.
+        let zero = T::zero();
+        let is_nonnegative = x >= zero;
+        let mut buf = [0; 64];
+        let mut curr = buf.len();
+        let base = T::from_u8(self.base());
+        if is_nonnegative {
+            // Accumulate each digit of the number from the least significant
+            // to the most significant figure.
+            for byte in buf.iter_mut().rev() {
+                let n = x % base;              // Get the current place value.
+                x = x / base;                  // Deaccumulate the number.
+                *byte = self.digit(n.to_u8()); // Store the digit in the buffer.
+                curr -= 1;
+                if x == zero {
+                    // No more digits left to accumulate.
+                    break
+                };
+            }
+        } else {
+            // Do the same as above, but accounting for two's complement.
+            for byte in buf.iter_mut().rev() {
+                let n = zero - (x % base);     // Get the current place value.
+                x = x / base;                  // Deaccumulate the number.
+                *byte = self.digit(n.to_u8()); // Store the digit in the buffer.
+                curr -= 1;
+                if x == zero {
+                    // No more digits left to accumulate.
+                    break
+                };
+            }
+        }
+        let buf = unsafe { str::from_utf8_unchecked(&buf[curr..]) };
+        f.pad_integral(is_nonnegative, self.prefix(), buf)
+    }
+}
+
+/// A binary (base 2) radix
+#[derive(Clone, PartialEq)]
+struct Binary;
+
+/// An octal (base 8) radix
+#[derive(Clone, PartialEq)]
+struct Octal;
+
+/// A decimal (base 10) radix
+#[derive(Clone, PartialEq)]
+struct Decimal;
+
+/// A hexadecimal (base 16) radix, formatted with lower-case characters
+#[derive(Clone, PartialEq)]
+struct LowerHex;
+
+/// A hexadecimal (base 16) radix, formatted with upper-case characters
+#[derive(Clone, PartialEq)]
+struct UpperHex;
+
+macro_rules! radix {
+    ($T:ident, $base:expr, $prefix:expr, $($x:pat => $conv:expr),+) => {
+        impl GenericRadix for $T {
+            fn base(&self) -> u8 { $base }
+            fn prefix(&self) -> &'static str { $prefix }
+            fn digit(&self, x: u8) -> u8 {
+                match x {
+                    $($x => $conv,)+
+                    x => panic!("number not in the range 0..{}: {}", self.base() - 1, x),
+                }
+            }
+        }
+    }
+}
+
+radix! { Binary,    2, "0b", x @  0 ...  2 => b'0' + x }
+radix! { Octal,     8, "0o", x @  0 ...  7 => b'0' + x }
+radix! { Decimal,  10, "",   x @  0 ...  9 => b'0' + x }
+radix! { LowerHex, 16, "0x", x @  0 ...  9 => b'0' + x,
+                             x @ 10 ... 15 => b'a' + (x - 10) }
+radix! { UpperHex, 16, "0x", x @  0 ...  9 => b'0' + x,
+                             x @ 10 ... 15 => b'A' + (x - 10) }
+
+macro_rules! int_base {
+    ($Trait:ident for $T:ident as $U:ident -> $Radix:ident) => {
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl fmt::$Trait for $T {
+            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                $Radix.fmt_int(*self as $U, f)
+            }
+        }
+    }
+}
+
+macro_rules! debug {
+    ($T:ident) => {
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl fmt::Debug for $T {
+            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                fmt::Display::fmt(self, f)
+            }
+        }
+    }
+}
+
+macro_rules! integer {
+    ($Int:ident, $Uint:ident) => {
+        int_base! { Binary   for $Int as $Uint  -> Binary }
+        int_base! { Octal    for $Int as $Uint  -> Octal }
+        int_base! { LowerHex for $Int as $Uint  -> LowerHex }
+        int_base! { UpperHex for $Int as $Uint  -> UpperHex }
+        debug! { $Int }
+
+        int_base! { Binary   for $Uint as $Uint -> Binary }
+        int_base! { Octal    for $Uint as $Uint -> Octal }
+        int_base! { LowerHex for $Uint as $Uint -> LowerHex }
+        int_base! { UpperHex for $Uint as $Uint -> UpperHex }
+        debug! { $Uint }
+    }
+}
+integer! { isize, usize }
+integer! { i8, u8 }
+integer! { i16, u16 }
+integer! { i32, u32 }
+integer! { i64, u64 }
+
+const DEC_DIGITS_LUT: &'static[u8] =
+    b"0001020304050607080910111213141516171819\
+      2021222324252627282930313233343536373839\
+      4041424344454647484950515253545556575859\
+      6061626364656667686970717273747576777879\
+      8081828384858687888990919293949596979899";
+
+macro_rules! impl_Display {
+    ($($t:ident),*: $conv_fn:ident) => ($(
+    #[stable(feature = "rust1", since = "1.0.0")]
+    impl fmt::Display for $t {
+        #[allow(unused_comparisons)]
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            let is_nonnegative = *self >= 0;
+            let mut n = if is_nonnegative {
+                self.$conv_fn()
+            } else {
+                // convert the negative num to positive by summing 1 to it's 2 complement
+                (!self.$conv_fn()).wrapping_add(1)
+            };
+            let mut buf: [u8; 20] = unsafe { mem::uninitialized() };
+            let mut curr = buf.len() as isize;
+            let buf_ptr = buf.as_mut_ptr();
+            let lut_ptr = DEC_DIGITS_LUT.as_ptr();
+
+            unsafe {
+                // eagerly decode 4 characters at a time
+                if <$t>::max_value() as u64 >= 10000 {
+                    while n >= 10000 {
+                        let rem = (n % 10000) as isize;
+                        n /= 10000;
+
+                        let d1 = (rem / 100) << 1;
+                        let d2 = (rem % 100) << 1;
+                        curr -= 4;
+                        ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                        ptr::copy_nonoverlapping(lut_ptr.offset(d2), buf_ptr.offset(curr + 2), 2);
+                    }
+                }
+
+                // if we reach here numbers are <= 9999, so at most 4 chars long
+                let mut n = n as isize; // possibly reduce 64bit math
+
+                // decode 2 more chars, if > 2 chars
+                if n >= 100 {
+                    let d1 = (n % 100) << 1;
+                    n /= 100;
+                    curr -= 2;
+                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                }
+
+                // decode last 1 or 2 chars
+                if n < 10 {
+                    curr -= 1;
+                    *buf_ptr.offset(curr) = (n as u8) + 48;
+                } else {
+                    let d1 = n << 1;
+                    curr -= 2;
+                    ptr::copy_nonoverlapping(lut_ptr.offset(d1), buf_ptr.offset(curr), 2);
+                }
+            }
+
+            let buf_slice = unsafe {
+                str::from_utf8_unchecked(
+                    slice::from_raw_parts(buf_ptr.offset(curr), buf.len() - curr as usize))
+            };
+            f.pad_integral(is_nonnegative, "", buf_slice)
+        }
+    })*);
+}
+
+impl_Display!(i8, u8, i16, u16, i32, u32: to_u32);
+impl_Display!(i64, u64: to_u64);
+#[cfg(target_pointer_width = "32")]
+impl_Display!(isize, usize: to_u32);
+#[cfg(target_pointer_width = "64")]
+impl_Display!(isize, usize: to_u64);