From 5e1b4546c3dd6d98653f70acc8b81eb6d8c7d61c Mon Sep 17 00:00:00 2001
From: patr0nus <dk4rest@gmail.com>
Date: Mon, 7 Nov 2022 19:06:49 +0800
Subject: [PATCH] Add ByteString::slice_ref
---
bytestring/src/lib.rs | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)
diff --git a/bytestring/src/lib.rs b/bytestring/src/lib.rs
index 27357602..06117d7c 100644
--- a/bytestring/src/lib.rs
+++ b/bytestring/src/lib.rs
@@ -50,6 +50,34 @@ impl ByteString {
pub const unsafe fn from_bytes_unchecked(src: Bytes) -> ByteString {
Self(src)
}
+
+ /// Returns a slice of self that is equivalent to the given `subset`. Corresponds to [`Bytes::slice_ref`].
+ ///
+ /// When processing a `ByteString` buffer with other tools, one often gets a
+ /// `&str` which is in fact a slice of the `ByteString`, i.e. a subset of it.
+ /// This function turns that `&str` into another `ByteString`, as if one had
+ /// sliced the `ByteString` with the offsets that correspond to `subset`.
+ ///
+ /// This operation is `O(1)`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use bytestring::ByteString;
+ ///
+ /// let string = ByteString::from_static(" foo ");
+ /// let subset = string.trim();
+ /// let substring = string.slice_ref(subset);
+ /// assert_eq!(substring, "foo");
+ /// ```
+ ///
+ /// # Panics
+ ///
+ /// Requires that the given `subset` str is in fact contained within the
+ /// `ByteString` buffer; otherwise this function will panic.
+ pub fn slice_ref(&self, subset: &str) -> Self {
+ Self(self.0.slice_ref(subset.as_bytes()))
+ }
}
impl PartialEq<str> for ByteString {
@@ -349,4 +377,10 @@ mod test {
let s = serde_json::to_string(&ByteString::from_static("nice bytes")).unwrap();
assert_eq!(s, r#""nice bytes""#);
}
+
+ #[test]
+ #[should_panic]
+ fn test_slice_ref_catches_not_a_subset() {
+ ByteString::from_static("foo bar").slice_ref("foo");
+ }
}