justfile

@@ -1,6 +0,0 @@
-_default:
-    just --list
-
-
-test:
-    cargo nextest run

src/combinators.rs

@@ -16,13 +16,3 @@ where
         Ok((results, acc))
     }
 }
-
-pub fn optional<I, O, E>(parser: impl Parser<I, O, E>) -> impl Parser<I, Option<O>, E>
-where
-    I: Clone,
-{
-    move |input: I| match parser.parse(input.clone()) {
-        Ok((output, rest)) => Ok((Some(output), rest)),
-        Err(_e) => Ok((None, input)),
-    }
-}

src/lib.rs

@@ -74,17 +74,4 @@ mod tests {
         let output = parser.parse("aaaaaaaabcd").unwrap();
         assert_eq! {((10, 'b'), "cd"), output};
     }
-
-    #[test]
-    fn test_optional() {
-        let parser = sequence(
-            optional(literal("alpha")),
-            sequence(repeated(literal(" ")), literal("beta")),
-        );
-
-        let output1 = parser.parse("   beta").unwrap();
-        assert_eq!(output1.0 .0, None);
-        let output2 = parser.parse("alpha   beta").unwrap();
-        assert_eq!(output2.0 .0, Some("alpha"));
-    }
 }