Import 'regex' package vesion 1.3.6
* Add OWNERS
* No Android.bp yet
Bug: 152884384
Test: make
Change-Id: I455caf7833b6c437c1c133bc7b2f47b83da9cbce
diff --git a/src/expand.rs b/src/expand.rs
new file mode 100644
index 0000000..528f55e
--- /dev/null
+++ b/src/expand.rs
@@ -0,0 +1,220 @@
+use std::str;
+
+use find_byte::find_byte;
+
+use re_bytes;
+use re_unicode;
+
+pub fn expand_str(
+ caps: &re_unicode::Captures,
+ mut replacement: &str,
+ dst: &mut String,
+) {
+ while !replacement.is_empty() {
+ match find_byte(b'$', replacement.as_bytes()) {
+ None => break,
+ Some(i) => {
+ dst.push_str(&replacement[..i]);
+ replacement = &replacement[i..];
+ }
+ }
+ if replacement.as_bytes().get(1).map_or(false, |&b| b == b'$') {
+ dst.push_str("$");
+ replacement = &replacement[2..];
+ continue;
+ }
+ debug_assert!(!replacement.is_empty());
+ let cap_ref = match find_cap_ref(replacement) {
+ Some(cap_ref) => cap_ref,
+ None => {
+ dst.push_str("$");
+ replacement = &replacement[1..];
+ continue;
+ }
+ };
+ replacement = &replacement[cap_ref.end..];
+ match cap_ref.cap {
+ Ref::Number(i) => {
+ dst.push_str(caps.get(i).map(|m| m.as_str()).unwrap_or(""));
+ }
+ Ref::Named(name) => {
+ dst.push_str(
+ caps.name(name).map(|m| m.as_str()).unwrap_or(""),
+ );
+ }
+ }
+ }
+ dst.push_str(replacement);
+}
+
+pub fn expand_bytes(
+ caps: &re_bytes::Captures,
+ mut replacement: &[u8],
+ dst: &mut Vec<u8>,
+) {
+ while !replacement.is_empty() {
+ match find_byte(b'$', replacement) {
+ None => break,
+ Some(i) => {
+ dst.extend(&replacement[..i]);
+ replacement = &replacement[i..];
+ }
+ }
+ if replacement.get(1).map_or(false, |&b| b == b'$') {
+ dst.push(b'$');
+ replacement = &replacement[2..];
+ continue;
+ }
+ debug_assert!(!replacement.is_empty());
+ let cap_ref = match find_cap_ref(replacement) {
+ Some(cap_ref) => cap_ref,
+ None => {
+ dst.push(b'$');
+ replacement = &replacement[1..];
+ continue;
+ }
+ };
+ replacement = &replacement[cap_ref.end..];
+ match cap_ref.cap {
+ Ref::Number(i) => {
+ dst.extend(caps.get(i).map(|m| m.as_bytes()).unwrap_or(b""));
+ }
+ Ref::Named(name) => {
+ dst.extend(
+ caps.name(name).map(|m| m.as_bytes()).unwrap_or(b""),
+ );
+ }
+ }
+ }
+ dst.extend(replacement);
+}
+
+/// `CaptureRef` represents a reference to a capture group inside some text.
+/// The reference is either a capture group name or a number.
+///
+/// It is also tagged with the position in the text following the
+/// capture reference.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+struct CaptureRef<'a> {
+ cap: Ref<'a>,
+ end: usize,
+}
+
+/// A reference to a capture group in some text.
+///
+/// e.g., `$2`, `$foo`, `${foo}`.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+enum Ref<'a> {
+ Named(&'a str),
+ Number(usize),
+}
+
+impl<'a> From<&'a str> for Ref<'a> {
+ fn from(x: &'a str) -> Ref<'a> {
+ Ref::Named(x)
+ }
+}
+
+impl From<usize> for Ref<'static> {
+ fn from(x: usize) -> Ref<'static> {
+ Ref::Number(x)
+ }
+}
+
+/// Parses a possible reference to a capture group name in the given text,
+/// starting at the beginning of `replacement`.
+///
+/// If no such valid reference could be found, None is returned.
+fn find_cap_ref<T: ?Sized + AsRef<[u8]>>(
+ replacement: &T,
+) -> Option<CaptureRef> {
+ let mut i = 0;
+ let rep: &[u8] = replacement.as_ref();
+ if rep.len() <= 1 || rep[0] != b'$' {
+ return None;
+ }
+ let mut brace = false;
+ i += 1;
+ if rep[i] == b'{' {
+ brace = true;
+ i += 1;
+ }
+ let mut cap_end = i;
+ while rep.get(cap_end).map_or(false, is_valid_cap_letter) {
+ cap_end += 1;
+ }
+ if cap_end == i {
+ return None;
+ }
+ // We just verified that the range 0..cap_end is valid ASCII, so it must
+ // therefore be valid UTF-8. If we really cared, we could avoid this UTF-8
+ // check with either unsafe or by parsing the number straight from &[u8].
+ let cap =
+ str::from_utf8(&rep[i..cap_end]).expect("valid UTF-8 capture name");
+ if brace {
+ if !rep.get(cap_end).map_or(false, |&b| b == b'}') {
+ return None;
+ }
+ cap_end += 1;
+ }
+ Some(CaptureRef {
+ cap: match cap.parse::<u32>() {
+ Ok(i) => Ref::Number(i as usize),
+ Err(_) => Ref::Named(cap),
+ },
+ end: cap_end,
+ })
+}
+
+/// Returns true if and only if the given byte is allowed in a capture name.
+fn is_valid_cap_letter(b: &u8) -> bool {
+ match *b {
+ b'0'..=b'9' | b'a'..=b'z' | b'A'..=b'Z' | b'_' => true,
+ _ => false,
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::{find_cap_ref, CaptureRef};
+
+ macro_rules! find {
+ ($name:ident, $text:expr) => {
+ #[test]
+ fn $name() {
+ assert_eq!(None, find_cap_ref($text));
+ }
+ };
+ ($name:ident, $text:expr, $capref:expr) => {
+ #[test]
+ fn $name() {
+ assert_eq!(Some($capref), find_cap_ref($text));
+ }
+ };
+ }
+
+ macro_rules! c {
+ ($name_or_number:expr, $pos:expr) => {
+ CaptureRef { cap: $name_or_number.into(), end: $pos }
+ };
+ }
+
+ find!(find_cap_ref1, "$foo", c!("foo", 4));
+ find!(find_cap_ref2, "${foo}", c!("foo", 6));
+ find!(find_cap_ref3, "$0", c!(0, 2));
+ find!(find_cap_ref4, "$5", c!(5, 2));
+ find!(find_cap_ref5, "$10", c!(10, 3));
+ // see https://github.com/rust-lang/regex/pull/585 for more on characters following numbers
+ find!(find_cap_ref6, "$42a", c!("42a", 4));
+ find!(find_cap_ref7, "${42}a", c!(42, 5));
+ find!(find_cap_ref8, "${42");
+ find!(find_cap_ref9, "${42 ");
+ find!(find_cap_ref10, " $0 ");
+ find!(find_cap_ref11, "$");
+ find!(find_cap_ref12, " ");
+ find!(find_cap_ref13, "");
+ find!(find_cap_ref14, "$1-$2", c!(1, 2));
+ find!(find_cap_ref15, "$1_$2", c!("1_", 3));
+ find!(find_cap_ref16, "$x-$y", c!("x", 2));
+ find!(find_cap_ref17, "$x_$y", c!("x_", 3));
+}