--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rust/hg-core/src/re2/re2.rs	Thu Jan 16 13:34:04 2020 +0100
@@ -0,0 +1,66 @@
+/*
+re2.rs
+
+Rust FFI bindings to Re2.
+
+Copyright 2020 Valentin Gatien-Baron
+
+This software may be used and distributed according to the terms of the
+GNU General Public License version 2 or any later version.
+*/
+use libc::{c_int, c_void};
+
+type Re2Ptr = *const c_void;
+
+pub struct Re2(Re2Ptr);
+
+/// `re2.h` says:
+/// "An "RE2" object is safe for concurrent use by multiple threads."
+unsafe impl Sync for Re2 {}
+
+/// These bind to the C ABI in `rust_re2.cpp`.
+extern "C" {
+    fn rust_re2_create(data: *const u8, len: usize) -> Re2Ptr;
+    fn rust_re2_destroy(re2: Re2Ptr);
+    fn rust_re2_ok(re2: Re2Ptr) -> bool;
+    fn rust_re2_error(
+        re2: Re2Ptr,
+        outdata: *mut *const u8,
+        outlen: *mut usize,
+    ) -> bool;
+    fn rust_re2_match(
+        re2: Re2Ptr,
+        data: *const u8,
+        len: usize,
+        anchor: c_int,
+    ) -> bool;
+}
+
+impl Re2 {
+    pub fn new(pattern: &[u8]) -> Result<Re2, String> {
+        unsafe {
+            let re2 = rust_re2_create(pattern.as_ptr(), pattern.len());
+            if rust_re2_ok(re2) {
+                Ok(Re2(re2))
+            } else {
+                let mut data: *const u8 = std::ptr::null();
+                let mut len: usize = 0;
+                rust_re2_error(re2, &mut data, &mut len);
+                Err(String::from_utf8_lossy(std::slice::from_raw_parts(
+                    data, len,
+                ))
+                .to_string())
+            }
+        }
+    }
+
+    pub fn is_match(&self, data: &[u8]) -> bool {
+        unsafe { rust_re2_match(self.0, data.as_ptr(), data.len(), 1) }
+    }
+}
+
+impl Drop for Re2 {
+    fn drop(&mut self) {
+        unsafe { rust_re2_destroy(self.0) }
+    }
+}