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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-04 12:47:55 +0000
commit2aadc03ef15cb5ca5cc2af8a7c08e070742f0ac4 (patch)
tree033cc839730fda84ff08db877037977be94e5e3a /vendor/regex-syntax/src/debug.rs
parentInitial commit. (diff)
downloadcargo-upstream.tar.xz
cargo-upstream.zip
Adding upstream version 0.70.1+ds1.upstream/0.70.1+ds1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/regex-syntax/src/debug.rs')
-rw-r--r--vendor/regex-syntax/src/debug.rs107
1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/regex-syntax/src/debug.rs b/vendor/regex-syntax/src/debug.rs
new file mode 100644
index 0000000..a0b051b
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+++ b/vendor/regex-syntax/src/debug.rs
@@ -0,0 +1,107 @@
+/// A type that wraps a single byte with a convenient fmt::Debug impl that
+/// escapes the byte.
+pub(crate) struct Byte(pub(crate) u8);
+
+impl core::fmt::Debug for Byte {
+ fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+ // Special case ASCII space. It's too hard to read otherwise, so
+ // put quotes around it. I sometimes wonder whether just '\x20' would
+ // be better...
+ if self.0 == b' ' {
+ return write!(f, "' '");
+ }
+ // 10 bytes is enough to cover any output from ascii::escape_default.
+ let mut bytes = [0u8; 10];
+ let mut len = 0;
+ for (i, mut b) in core::ascii::escape_default(self.0).enumerate() {
+ // capitalize \xab to \xAB
+ if i >= 2 && b'a' <= b && b <= b'f' {
+ b -= 32;
+ }
+ bytes[len] = b;
+ len += 1;
+ }
+ write!(f, "{}", core::str::from_utf8(&bytes[..len]).unwrap())
+ }
+}
+
+/// A type that provides a human readable debug impl for arbitrary bytes.
+///
+/// This generally works best when the bytes are presumed to be mostly UTF-8,
+/// but will work for anything.
+///
+/// N.B. This is copied nearly verbatim from regex-automata. Sigh.
+pub(crate) struct Bytes<'a>(pub(crate) &'a [u8]);
+
+impl<'a> core::fmt::Debug for Bytes<'a> {
+ fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+ write!(f, "\"")?;
+ // This is a sad re-implementation of a similar impl found in bstr.
+ let mut bytes = self.0;
+ while let Some(result) = utf8_decode(bytes) {
+ let ch = match result {
+ Ok(ch) => ch,
+ Err(byte) => {
+ write!(f, r"\x{:02x}", byte)?;
+ bytes = &bytes[1..];
+ continue;
+ }
+ };
+ bytes = &bytes[ch.len_utf8()..];
+ match ch {
+ '\0' => write!(f, "\\0")?,
+ // ASCII control characters except \0, \n, \r, \t
+ '\x01'..='\x08'
+ | '\x0b'
+ | '\x0c'
+ | '\x0e'..='\x19'
+ | '\x7f' => {
+ write!(f, "\\x{:02x}", u32::from(ch))?;
+ }
+ '\n' | '\r' | '\t' | _ => {
+ write!(f, "{}", ch.escape_debug())?;
+ }
+ }
+ }
+ write!(f, "\"")?;
+ Ok(())
+ }
+}
+
+/// Decodes the next UTF-8 encoded codepoint from the given byte slice.
+///
+/// If no valid encoding of a codepoint exists at the beginning of the given
+/// byte slice, then the first byte is returned instead.
+///
+/// This returns `None` if and only if `bytes` is empty.
+pub(crate) fn utf8_decode(bytes: &[u8]) -> Option<Result<char, u8>> {
+ fn len(byte: u8) -> Option<usize> {
+ if byte <= 0x7F {
+ return Some(1);
+ } else if byte & 0b1100_0000 == 0b1000_0000 {
+ return None;
+ } else if byte <= 0b1101_1111 {
+ Some(2)
+ } else if byte <= 0b1110_1111 {
+ Some(3)
+ } else if byte <= 0b1111_0111 {
+ Some(4)
+ } else {
+ None
+ }
+ }
+
+ if bytes.is_empty() {
+ return None;
+ }
+ let len = match len(bytes[0]) {
+ None => return Some(Err(bytes[0])),
+ Some(len) if len > bytes.len() => return Some(Err(bytes[0])),
+ Some(1) => return Some(Ok(char::from(bytes[0]))),
+ Some(len) => len,
+ };
+ match core::str::from_utf8(&bytes[..len]) {
+ Ok(s) => Some(Ok(s.chars().next().unwrap())),
+ Err(_) => Some(Err(bytes[0])),
+ }
+}