Auto merge of #48735 - 1011X:master, r=alexcrichton

Move ascii::escape_default to libcore

As requested in #46409, the `ascii::escape_default` method has been added to the core library. All I did was copy over the `std::ascii` module file, remove the (redundant) `AsciiExt` trait, and change some of the documentation to match. None of the tests were changed.

I wasn't sure how to handle the annotations. For `EscapeDefault` and `escape_default()`, I changed them to `#[unstable(feature = "core_ascii", issue = "46409")]`. Is that alright? Or should I leave them as they were?

1 files changed, 2 insertions, 477 deletions

diff --git a/src/libstd/ascii.rs b/src/libstd/ascii.rs
index d5bf9e9bb2f..0837ff91c14 100644
--- a/src/libstd/ascii.rs
+++ b/src/libstd/ascii.rs
@@ -26,9 +26,8 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use fmt;
-use ops::Range;
-use iter::FusedIterator;
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use core::ascii::{EscapeDefault, escape_default};
 
 /// Extension methods for ASCII-subset only operations.
 ///
@@ -483,477 +482,3 @@ impl AsciiExt for str {
         self.bytes().all(|b| b.is_ascii_control())
     }
 }
-
-/// An iterator over the escaped version of a byte.
-///
-/// This `struct` is created by the [`escape_default`] function. See its
-/// documentation for more.
-///
-/// [`escape_default`]: fn.escape_default.html
-#[stable(feature = "rust1", since = "1.0.0")]
-pub struct EscapeDefault {
-    range: Range<usize>,
-    data: [u8; 4],
-}
-
-/// Returns an iterator that produces an escaped version of a `u8`.
-///
-/// The default is chosen with a bias toward producing literals that are
-/// legal in a variety of languages, including C++11 and similar C-family
-/// languages. The exact rules are:
-///
-/// - Tab, CR and LF are escaped as '\t', '\r' and '\n' respectively.
-/// - Single-quote, double-quote and backslash chars are backslash-escaped.
-/// - Any other chars in the range [0x20,0x7e] are not escaped.
-/// - Any other chars are given hex escapes of the form '\xNN'.
-/// - Unicode escapes are never generated by this function.
-///
-/// # Examples
-///
-/// ```
-/// use std::ascii;
-///
-/// let escaped = ascii::escape_default(b'0').next().unwrap();
-/// assert_eq!(b'0', escaped);
-///
-/// let mut escaped = ascii::escape_default(b'\t');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b't', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'\r');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'r', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'\n');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'n', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'\'');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'\'', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'"');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'"', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'\\');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'\\', escaped.next().unwrap());
-///
-/// let mut escaped = ascii::escape_default(b'\x9d');
-///
-/// assert_eq!(b'\\', escaped.next().unwrap());
-/// assert_eq!(b'x', escaped.next().unwrap());
-/// assert_eq!(b'9', escaped.next().unwrap());
-/// assert_eq!(b'd', escaped.next().unwrap());
-/// ```
-#[stable(feature = "rust1", since = "1.0.0")]
-pub fn escape_default(c: u8) -> EscapeDefault {
-    let (data, len) = match c {
-        b'\t' => ([b'\\', b't', 0, 0], 2),
-        b'\r' => ([b'\\', b'r', 0, 0], 2),
-        b'\n' => ([b'\\', b'n', 0, 0], 2),
-        b'\\' => ([b'\\', b'\\', 0, 0], 2),
-        b'\'' => ([b'\\', b'\'', 0, 0], 2),
-        b'"' => ([b'\\', b'"', 0, 0], 2),
-        b'\x20' ... b'\x7e' => ([c, 0, 0, 0], 1),
-        _ => ([b'\\', b'x', hexify(c >> 4), hexify(c & 0xf)], 4),
-    };
-
-    return EscapeDefault { range: (0.. len), data: data };
-
-    fn hexify(b: u8) -> u8 {
-        match b {
-            0 ... 9 => b'0' + b,
-            _ => b'a' + b - 10,
-        }
-    }
-}
-
-#[stable(feature = "rust1", since = "1.0.0")]
-impl Iterator for EscapeDefault {
-    type Item = u8;
-    fn next(&mut self) -> Option<u8> { self.range.next().map(|i| self.data[i]) }
-    fn size_hint(&self) -> (usize, Option<usize>) { self.range.size_hint() }
-}
-#[stable(feature = "rust1", since = "1.0.0")]
-impl DoubleEndedIterator for EscapeDefault {
-    fn next_back(&mut self) -> Option<u8> {
-        self.range.next_back().map(|i| self.data[i])
-    }
-}
-#[stable(feature = "rust1", since = "1.0.0")]
-impl ExactSizeIterator for EscapeDefault {}
-#[stable(feature = "fused", since = "1.26.0")]
-impl FusedIterator for EscapeDefault {}
-
-#[stable(feature = "std_debug", since = "1.16.0")]
-impl fmt::Debug for EscapeDefault {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.pad("EscapeDefault { .. }")
-    }
-}
-
-
-#[cfg(test)]
-mod tests {
-    //! Note that most of these tests are not testing `AsciiExt` methods, but
-    //! test inherent ascii methods of char, u8, str and [u8]. `AsciiExt` is
-    //! just using those methods, though.
-    use super::AsciiExt;
-    use char::from_u32;
-
-    #[test]
-    fn test_is_ascii() {
-        assert!(b"".is_ascii());
-        assert!(b"banana\0\x7F".is_ascii());
-        assert!(b"banana\0\x7F".iter().all(|b| b.is_ascii()));
-        assert!(!b"Vi\xe1\xbb\x87t Nam".is_ascii());
-        assert!(!b"Vi\xe1\xbb\x87t Nam".iter().all(|b| b.is_ascii()));
-        assert!(!b"\xe1\xbb\x87".iter().any(|b| b.is_ascii()));
-
-        assert!("".is_ascii());
-        assert!("banana\0\u{7F}".is_ascii());
-        assert!("banana\0\u{7F}".chars().all(|c| c.is_ascii()));
-        assert!(!"ประเทศไทย中华Việt Nam".chars().all(|c| c.is_ascii()));
-        assert!(!"ประเทศไทย中华ệ ".chars().any(|c| c.is_ascii()));
-    }
-
-    #[test]
-    fn test_to_ascii_uppercase() {
-        assert_eq!("url()URL()uRl()ürl".to_ascii_uppercase(), "URL()URL()URL()üRL");
-        assert_eq!("hıKß".to_ascii_uppercase(), "HıKß");
-
-        for i in 0..501 {
-            let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 }
-                        else { i };
-            assert_eq!((from_u32(i).unwrap()).to_string().to_ascii_uppercase(),
-                       (from_u32(upper).unwrap()).to_string());
-        }
-    }
-
-    #[test]
-    fn test_to_ascii_lowercase() {
-        assert_eq!("url()URL()uRl()Ürl".to_ascii_lowercase(), "url()url()url()Ürl");
-        // Dotted capital I, Kelvin sign, Sharp S.
-        assert_eq!("HİKß".to_ascii_lowercase(), "hİKß");
-
-        for i in 0..501 {
-            let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
-                        else { i };
-            assert_eq!((from_u32(i).unwrap()).to_string().to_ascii_lowercase(),
-                       (from_u32(lower).unwrap()).to_string());
-        }
-    }
-
-    #[test]
-    fn test_make_ascii_lower_case() {
-        macro_rules! test {
-            ($from: expr, $to: expr) => {
-                {
-                    let mut x = $from;
-                    x.make_ascii_lowercase();
-                    assert_eq!(x, $to);
-                }
-            }
-        }
-        test!(b'A', b'a');
-        test!(b'a', b'a');
-        test!(b'!', b'!');
-        test!('A', 'a');
-        test!('À', 'À');
-        test!('a', 'a');
-        test!('!', '!');
-        test!(b"H\xc3\x89".to_vec(), b"h\xc3\x89");
-        test!("HİKß".to_string(), "hİKß");
-    }
-
-
-    #[test]
-    fn test_make_ascii_upper_case() {
-        macro_rules! test {
-            ($from: expr, $to: expr) => {
-                {
-                    let mut x = $from;
-                    x.make_ascii_uppercase();
-                    assert_eq!(x, $to);
-                }
-            }
-        }
-        test!(b'a', b'A');
-        test!(b'A', b'A');
-        test!(b'!', b'!');
-        test!('a', 'A');
-        test!('à', 'à');
-        test!('A', 'A');
-        test!('!', '!');
-        test!(b"h\xc3\xa9".to_vec(), b"H\xc3\xa9");
-        test!("hıKß".to_string(), "HıKß");
-
-        let mut x = "Hello".to_string();
-        x[..3].make_ascii_uppercase();  // Test IndexMut on String.
-        assert_eq!(x, "HELlo")
-    }
-
-    #[test]
-    fn test_eq_ignore_ascii_case() {
-        assert!("url()URL()uRl()Ürl".eq_ignore_ascii_case("url()url()url()Ürl"));
-        assert!(!"Ürl".eq_ignore_ascii_case("ürl"));
-        // Dotted capital I, Kelvin sign, Sharp S.
-        assert!("HİKß".eq_ignore_ascii_case("hİKß"));
-        assert!(!"İ".eq_ignore_ascii_case("i"));
-        assert!(!"K".eq_ignore_ascii_case("k"));
-        assert!(!"ß".eq_ignore_ascii_case("s"));
-
-        for i in 0..501 {
-            let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
-                        else { i };
-            assert!((from_u32(i).unwrap()).to_string().eq_ignore_ascii_case(
-                    &from_u32(lower).unwrap().to_string()));
-        }
-    }
-
-    #[test]
-    fn inference_works() {
-        let x = "a".to_string();
-        x.eq_ignore_ascii_case("A");
-    }
-
-    // Shorthands used by the is_ascii_* tests.
-    macro_rules! assert_all {
-        ($what:ident, $($str:tt),+) => {{
-            $(
-                for b in $str.chars() {
-                    if !b.$what() {
-                        panic!("expected {}({}) but it isn't",
-                               stringify!($what), b);
-                    }
-                }
-                for b in $str.as_bytes().iter() {
-                    if !b.$what() {
-                        panic!("expected {}(0x{:02x})) but it isn't",
-                               stringify!($what), b);
-                    }
-                }
-                assert!($str.$what());
-                assert!($str.as_bytes().$what());
-            )+
-        }};
-        ($what:ident, $($str:tt),+,) => (assert_all!($what,$($str),+))
-    }
-    macro_rules! assert_none {
-        ($what:ident, $($str:tt),+) => {{
-            $(
-                for b in $str.chars() {
-                    if b.$what() {
-                        panic!("expected not-{}({}) but it is",
-                               stringify!($what), b);
-                    }
-                }
-                for b in $str.as_bytes().iter() {
-                    if b.$what() {
-                        panic!("expected not-{}(0x{:02x})) but it is",
-                               stringify!($what), b);
-                    }
-                }
-            )*
-        }};
-        ($what:ident, $($str:tt),+,) => (assert_none!($what,$($str),+))
-    }
-
-    #[test]
-    fn test_is_ascii_alphabetic() {
-        assert_all!(is_ascii_alphabetic,
-            "",
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-        );
-        assert_none!(is_ascii_alphabetic,
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_uppercase() {
-        assert_all!(is_ascii_uppercase,
-            "",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-        );
-        assert_none!(is_ascii_uppercase,
-            "abcdefghijklmnopqrstuvwxyz",
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_lowercase() {
-        assert_all!(is_ascii_lowercase,
-            "abcdefghijklmnopqrstuvwxyz",
-        );
-        assert_none!(is_ascii_lowercase,
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_alphanumeric() {
-        assert_all!(is_ascii_alphanumeric,
-            "",
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-        );
-        assert_none!(is_ascii_alphanumeric,
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_digit() {
-        assert_all!(is_ascii_digit,
-            "",
-            "0123456789",
-        );
-        assert_none!(is_ascii_digit,
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_hexdigit() {
-        assert_all!(is_ascii_hexdigit,
-            "",
-            "0123456789",
-            "abcdefABCDEF",
-        );
-        assert_none!(is_ascii_hexdigit,
-            "ghijklmnopqrstuvwxyz",
-            "GHIJKLMNOQPRSTUVWXYZ",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_punctuation() {
-        assert_all!(is_ascii_punctuation,
-            "",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-        );
-        assert_none!(is_ascii_punctuation,
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_graphic() {
-        assert_all!(is_ascii_graphic,
-            "",
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-        );
-        assert_none!(is_ascii_graphic,
-            " \t\n\x0c\r",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_whitespace() {
-        assert_all!(is_ascii_whitespace,
-            "",
-            " \t\n\x0c\r",
-        );
-        assert_none!(is_ascii_whitespace,
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x0b\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-    }
-
-    #[test]
-    fn test_is_ascii_control() {
-        assert_all!(is_ascii_control,
-            "",
-            "\x00\x01\x02\x03\x04\x05\x06\x07",
-            "\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
-            "\x10\x11\x12\x13\x14\x15\x16\x17",
-            "\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
-            "\x7f",
-        );
-        assert_none!(is_ascii_control,
-            "abcdefghijklmnopqrstuvwxyz",
-            "ABCDEFGHIJKLMNOQPRSTUVWXYZ",
-            "0123456789",
-            "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~",
-            " ",
-        );
-    }
-}