fix(token)!: Dont require SliceLen for literal

This makes it easier to use `literal` with more types.
I also expect this doesn't lose out on much as `Needed` for a literal is
not likely to report the actual number of needed tokens but a small
amount for the next batch, likely too small to be worth trying to fetch
an exact amount.

src/ascii/mod.rs

@@ -92,7 +92,7 @@ impl Caseless<&str> {
 /// # use winnow::ascii::crlf;
 /// assert_eq!(crlf::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\r\nc")), Ok((Partial::new("c"), "\r\n")));
 /// assert!(crlf::<_, ErrMode<ContextError>>.parse_peek(Partial::new("ab\r\nc")).is_err());
-/// assert_eq!(crlf::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(2))));
+/// assert_eq!(crlf::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::Unknown)));
 /// ```
 #[inline(always)]
 pub fn crlf<Input, Error>(input: &mut Input) -> Result<<Input as Stream>::Slice, Error>
@@ -239,7 +239,7 @@ where
 /// # use winnow::ascii::line_ending;
 /// assert_eq!(line_ending::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\r\nc")), Ok((Partial::new("c"), "\r\n")));
 /// assert!(line_ending::<_, ErrMode<ContextError>>.parse_peek(Partial::new("ab\r\nc")).is_err());
-/// assert_eq!(line_ending::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(1))));
+/// assert_eq!(line_ending::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::Unknown)));
 /// ```
 #[inline(always)]
 pub fn line_ending<Input, Error>(input: &mut Input) -> Result<<Input as Stream>::Slice, Error>
@@ -288,7 +288,7 @@ where
 /// # use winnow::ascii::newline;
 /// assert_eq!(newline::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\nc")), Ok((Partial::new("c"), '\n')));
 /// assert!(newline::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\r\nc")).is_err());
-/// assert_eq!(newline::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(1))));
+/// assert_eq!(newline::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::Unknown)));
 /// ```
 #[inline(always)]
 pub fn newline<I, Error: ParserError<I>>(input: &mut I) -> Result<char, Error>
@@ -338,7 +338,7 @@ where
 /// # use winnow::ascii::tab;
 /// assert_eq!(tab::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\tc")), Ok((Partial::new("c"), '\t')));
 /// assert!(tab::<_, ErrMode<ContextError>>.parse_peek(Partial::new("\r\nc")).is_err());
-/// assert_eq!(tab::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::new(1))));
+/// assert_eq!(tab::<_, ErrMode<ContextError>>.parse_peek(Partial::new("")), Err(ErrMode::Incomplete(Needed::Unknown)));
 /// ```
 #[inline(always)]
 pub fn tab<Input, Error>(input: &mut Input) -> Result<char, Error>

src/ascii/tests.rs

@@ -4190,9 +4190,7 @@ Ok(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )
 
@@ -4242,9 +4240,7 @@ Ok(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )
 
@@ -4319,9 +4315,7 @@ Ok(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )
 
@@ -4387,9 +4381,7 @@ Ok(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )
 

src/binary/tests.rs

@@ -3212,9 +3212,7 @@ Ok(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )
 
@@ -3226,9 +3224,7 @@ Err(
             str![[r#"
 Err(
     Incomplete(
-        Size(
-            1,
-        ),
+        Unknown,
     ),
 )