add delete tag

src/lib.rs

@@ -40,6 +40,7 @@
 //! Default replacments from [`tag_impls`] are:
 //!
 //! * [`Original`] does not replace (leaves original match as is)
+//! * [`Delete`] deletes match
 //! * [`Literal`] puts given string
 //! * [`Any`] selects random inner tag with equal weights
 //! * [`Weights`] selects random inner tag based on relative weights
@@ -115,6 +116,7 @@
 //! [`Match`]: crate::Match
 //! [`Intensity`]: crate::intensity::Intensity
 //! [`Original`]: crate::tag_impls::Original
+//! [`Delete`]: crate::tag_impls::Delete
 //! [`Literal`]: crate::tag_impls::Literal
 //! [`Any`]: crate::tag_impls::Any
 //! [`Weights`]: crate::tag_impls::Weights

src/tag_impls.rs

@@ -30,6 +30,31 @@ impl Tag for Original {
     }
 }
 
+/// Deletes match
+///
+/// This is a shortcut for [`Literal`] with `""`
+#[derive(Clone, Debug)]
+#[cfg_attr(feature = "deserialize", derive(serde::Deserialize))]
+pub struct Delete;
+
+impl Delete {
+    #![allow(clippy::new_without_default)]
+    pub fn new() -> Self {
+        Self
+    }
+
+    pub fn new_boxed() -> Box<Self> {
+        Box::new(Self::new())
+    }
+}
+
+#[cfg_attr(feature = "deserialize", typetag::deserialize)]
+impl Tag for Delete {
+    fn generate<'a>(&self, _: &Match<'a>) -> Cow<'a, str> {
+        Cow::Borrowed("")
+    }
+}
+
 /// Static string
 ///
 /// Acts as regex template, syntax doc: <https://docs.rs/regex/latest/regex/struct.Regex.html#example-9>
@@ -310,6 +335,14 @@ mod tests {
         assert_eq!(apply(&tag, "foo"), "foo");
     }
 
+    #[test]
+    fn delete() {
+        let tag = Delete::new();
+
+        assert_eq!(apply(&tag, "bar"), "");
+        assert_eq!(apply(&tag, "foo"), "");
+    }
+
     #[test]
     fn literal() {
         let tag = Literal::new("bar");