From 23be3f4885688e5e0011005e2295c75168854c0a Mon Sep 17 00:00:00 2001 From: Fenrir Date: Sun, 21 Jan 2018 14:06:28 -0700 Subject: Recreate ctr-std from latest nightly --- ctr-std/src/sys_common/bytestring.rs | 56 ++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 ctr-std/src/sys_common/bytestring.rs (limited to 'ctr-std/src/sys_common/bytestring.rs') diff --git a/ctr-std/src/sys_common/bytestring.rs b/ctr-std/src/sys_common/bytestring.rs new file mode 100644 index 0000000..eb9cad0 --- /dev/null +++ b/ctr-std/src/sys_common/bytestring.rs @@ -0,0 +1,56 @@ +// 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +#![allow(dead_code)] + +use fmt::{Formatter, Result, Write}; +use std_unicode::lossy::{Utf8Lossy, Utf8LossyChunk}; + +pub fn debug_fmt_bytestring(slice: &[u8], f: &mut Formatter) -> Result { + // Writes out a valid unicode string with the correct escape sequences + fn write_str_escaped(f: &mut Formatter, s: &str) -> Result { + for c in s.chars().flat_map(|c| c.escape_debug()) { + f.write_char(c)? + } + Ok(()) + } + + f.write_str("\"")?; + for Utf8LossyChunk { valid, broken } in Utf8Lossy::from_bytes(slice).chunks() { + write_str_escaped(f, valid)?; + for b in broken { + write!(f, "\\x{:02X}", b)?; + } + } + f.write_str("\"") +} + +#[cfg(test)] +mod tests { + use super::*; + use fmt::{Formatter, Result, Debug}; + + #[test] + fn smoke() { + struct Helper<'a>(&'a [u8]); + + impl<'a> Debug for Helper<'a> { + fn fmt(&self, f: &mut Formatter) -> Result { + debug_fmt_bytestring(self.0, f) + } + } + + let input = b"\xF0hello,\tworld"; + let expected = r#""\xF0hello,\tworld""#; + let output = format!("{:?}", Helper(input)); + + assert!(output == expected); + } +} -- cgit v1.2.3