Split custom_keyword and custom_punctuation modules
diff --git a/src/custom_keyword.rs b/src/custom_keyword.rs
new file mode 100644
index 0000000..c9acaac
--- /dev/null
+++ b/src/custom_keyword.rs
@@ -0,0 +1,249 @@
+/// Define a type that supports parsing and printing a given identifier as if it
+/// were a keyword.
+///
+/// # Usage
+///
+/// As a convention, it is recommended that this macro be invoked within a
+/// module called `kw` or `keyword` and that the resulting parser be invoked
+/// with a `kw::` or `keyword::` prefix.
+///
+/// ```edition2018
+/// mod kw {
+///     syn::custom_keyword!(whatever);
+/// }
+/// ```
+///
+/// The generated syntax tree node supports the following operations just like
+/// any built-in keyword token.
+///
+/// - [Peeking] — `input.peek(kw::whatever)`
+///
+/// - [Parsing] — `input.parse::<kw::whatever>()?`
+///
+/// - [Printing] — `quote!( ... #whatever_token ... )`
+///
+/// - Construction from a [`Span`] — `let whatever_token = kw::whatever(sp)`
+///
+/// - Field access to its span — `let sp = whatever_token.span`
+///
+/// [Peeking]: parse/struct.ParseBuffer.html#method.peek
+/// [Parsing]: parse/struct.ParseBuffer.html#method.parse
+/// [Printing]: https://docs.rs/quote/0.6/quote/trait.ToTokens.html
+/// [`Span`]: https://docs.rs/proc-macro2/0.4/proc_macro2/struct.Span.html
+///
+/// # Example
+///
+/// This example parses input that looks like `bool = true` or `str = "value"`.
+/// The key must be either the identifier `bool` or the identifier `str`. If
+/// `bool`, the value may be either `true` or `false`. If `str`, the value may
+/// be any string literal.
+///
+/// The symbols `bool` and `str` are not reserved keywords in Rust so these are
+/// not considered keywords in the `syn::token` module. Like any other
+/// identifier that is not a keyword, these can be declared as custom keywords
+/// by crates that need to use them as such.
+///
+/// ```edition2018
+/// use syn::{LitBool, LitStr, Result, Token};
+/// use syn::parse::{Parse, ParseStream};
+///
+/// mod kw {
+///     syn::custom_keyword!(bool);
+///     syn::custom_keyword!(str);
+/// }
+///
+/// enum Argument {
+///     Bool {
+///         bool_token: kw::bool,
+///         eq_token: Token![=],
+///         value: LitBool,
+///     },
+///     Str {
+///         str_token: kw::str,
+///         eq_token: Token![=],
+///         value: LitStr,
+///     },
+/// }
+///
+/// impl Parse for Argument {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let lookahead = input.lookahead1();
+///         if lookahead.peek(kw::bool) {
+///             Ok(Argument::Bool {
+///                 bool_token: input.parse::<kw::bool>()?,
+///                 eq_token: input.parse()?,
+///                 value: input.parse()?,
+///             })
+///         } else if lookahead.peek(kw::str) {
+///             Ok(Argument::Str {
+///                 str_token: input.parse::<kw::str>()?,
+///                 eq_token: input.parse()?,
+///                 value: input.parse()?,
+///             })
+///         } else {
+///             Err(lookahead.error())
+///         }
+///     }
+/// }
+/// ```
+#[macro_export(local_inner_macros)]
+macro_rules! custom_keyword {
+    ($ident:ident) => {
+        #[allow(non_camel_case_types)]
+        pub struct $ident {
+            pub span: $crate::export::Span,
+        }
+
+        #[doc(hidden)]
+        #[allow(non_snake_case)]
+        pub fn $ident<__S: $crate::export::IntoSpans<[$crate::export::Span; 1]>>(
+            span: __S,
+        ) -> $ident {
+            $ident {
+                span: $crate::export::IntoSpans::into_spans(span)[0],
+            }
+        }
+
+        impl $crate::export::Default for $ident {
+            fn default() -> Self {
+                $ident {
+                    span: $crate::export::Span::call_site(),
+                }
+            }
+        }
+
+        impl_parse_for_custom_keyword!($ident);
+        impl_to_tokens_for_custom_keyword!($ident);
+        impl_clone_for_custom_keyword!($ident);
+        impl_extra_traits_for_custom_keyword!($ident);
+    };
+}
+
+// Not public API.
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_keyword {
+    ($ident:ident) => {
+        // For peek.
+        impl $crate::token::CustomToken for $ident {
+            fn peek(cursor: $crate::buffer::Cursor) -> $crate::export::bool {
+                if let Some((ident, _rest)) = cursor.ident() {
+                    ident == stringify!($ident)
+                } else {
+                    false
+                }
+            }
+
+            fn display() -> &'static $crate::export::str {
+                concat!("`", stringify!($ident), "`")
+            }
+        }
+
+        impl $crate::parse::Parse for $ident {
+            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
+                input.step(|cursor| {
+                    if let $crate::export::Some((ident, rest)) = cursor.ident() {
+                        if ident == stringify!($ident) {
+                            return $crate::export::Ok(($ident { span: ident.span() }, rest));
+                        }
+                    }
+                    $crate::export::Err(cursor.error(concat!(
+                        "expected `",
+                        stringify!($ident),
+                        "`"
+                    )))
+                })
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "parsing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::export::ToTokens for $ident {
+            fn to_tokens(&self, tokens: &mut $crate::export::TokenStream2) {
+                let ident = $crate::Ident::new(stringify!($ident), self.span);
+                $crate::export::TokenStreamExt::append(tokens, ident);
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "printing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "clone-impls")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::export::Copy for $ident {}
+
+        impl $crate::export::Clone for $ident {
+            fn clone(&self) -> Self {
+                *self
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "clone-impls"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_keyword {
+    ($ident:ident) => {};
+}
+
+// Not public API.
+#[cfg(feature = "extra-traits")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_keyword {
+    ($ident:ident) => {
+        impl $crate::export::Debug for $ident {
+            fn fmt(&self, f: &mut $crate::export::Formatter) -> $crate::export::fmt::Result {
+                $crate::export::Formatter::write_str(f, stringify!($ident))
+            }
+        }
+
+        impl $crate::export::Eq for $ident {}
+
+        impl $crate::export::PartialEq for $ident {
+            fn eq(&self, _other: &Self) -> $crate::export::bool {
+                true
+            }
+        }
+
+        impl $crate::export::Hash for $ident {
+            fn hash<__H: $crate::export::Hasher>(&self, _state: &mut __H) {}
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "extra-traits"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_keyword {
+    ($ident:ident) => {};
+}
diff --git a/src/custom_punctuation.rs b/src/custom_punctuation.rs
new file mode 100644
index 0000000..9284d02
--- /dev/null
+++ b/src/custom_punctuation.rs
@@ -0,0 +1,301 @@
+// Not public API.
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! punct_len {
+    ($mode:ident, +)      => ( 1usize );
+    ($mode:ident, +=)     => ( 2usize );
+    ($mode:ident, &)      => ( 1usize );
+    ($mode:ident, &&)     => ( 2usize );
+    ($mode:ident, &=)     => ( 2usize );
+    ($mode:ident, @)      => ( 1usize );
+    ($mode:ident, !)      => ( 1usize );
+    ($mode:ident, ^)      => ( 1usize );
+    ($mode:ident, ^=)     => ( 2usize );
+    ($mode:ident, :)      => ( 1usize );
+    ($mode:ident, ::)     => ( 2usize );
+    ($mode:ident, ,)      => ( 1usize );
+    ($mode:ident, /)      => ( 1usize );
+    ($mode:ident, /=)     => ( 2usize );
+    ($mode:ident, .)      => ( 1usize );
+    ($mode:ident, ..)     => ( 2usize );
+    ($mode:ident, ...)    => ( 3usize );
+    ($mode:ident, ..=)    => ( 3usize );
+    ($mode:ident, =)      => ( 1usize );
+    ($mode:ident, ==)     => ( 2usize );
+    ($mode:ident, >=)     => ( 2usize );
+    ($mode:ident, >)      => ( 1usize );
+    ($mode:ident, <=)     => ( 2usize );
+    ($mode:ident, <)      => ( 1usize );
+    ($mode:ident, *=)     => ( 2usize );
+    ($mode:ident, !=)     => ( 2usize );
+    ($mode:ident, |)      => ( 1usize );
+    ($mode:ident, |=)     => ( 2usize );
+    ($mode:ident, ||)     => ( 2usize );
+    ($mode:ident, #)      => ( 1usize );
+    ($mode:ident, ?)      => ( 1usize );
+    ($mode:ident, ->)     => ( 2usize );
+    ($mode:ident, <-)     => ( 2usize );
+    ($mode:ident, %)      => ( 1usize );
+    ($mode:ident, %=)     => ( 2usize );
+    ($mode:ident, =>)     => ( 2usize );
+    ($mode:ident, ;)      => ( 1usize );
+    ($mode:ident, <<)     => ( 2usize );
+    ($mode:ident, <<=)    => ( 3usize );
+    ($mode:ident, >>)     => ( 2usize );
+    ($mode:ident, >>=)    => ( 3usize );
+    ($mode:ident, *)      => ( 1usize );
+    ($mode:ident, -)      => ( 1usize );
+    ($mode:ident, -=)     => ( 2usize );
+    ($mode:ident, ~)      => ( 1usize );
+    (lenient, $tt:tt)     => ( 0usize );
+    (strict, $tt:tt)      => ({ unexpected!($tt); 0usize });
+    ($mode:ident, $head:tt $($tail:tt)+) => ( punct_len!($mode, $head) $(+ punct_len!($mode, $tail))+ );
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! unexpected {
+    () => {};
+}
+
+// Not public API.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! stringify_punct {
+    ($($tt:tt)+) => ( concat!($(stringify!($tt)),+) );
+}
+
+// Not public API.
+// Without this, local_inner_macros breaks when looking for concat!
+#[doc(hidden)]
+#[macro_export]
+macro_rules! my_concat {
+    ($($tt:tt)*) => ( concat!($($tt)*) );
+}
+
+/// Define a type that supports parsing and printing a multi-character symbol
+/// as if it were a token.
+///
+/// # Usage
+///
+/// As a convention, it is recommended that this macro be invoked within a
+/// module called `punct` or `punctuation` and that the resulting parser be invoked
+/// with a `punct::` or `punctuation::` prefix.
+///
+/// ```edition2018
+/// mod punct {
+///     syn::custom_punctuation!(LeftRightArrow, <=>);
+/// }
+/// ```
+///
+/// The generated syntax tree node supports the following operations just like
+/// any built-in punctuation token.
+///
+/// - [Peeking] — `input.peek(punct::LeftRightArrow)`
+///
+/// - [Parsing] — `input.parse::<punct::LeftRightArrow>()?`
+///
+/// - [Printing] — `quote!( ... #left_right_arrow ... )`
+///
+/// - Construction from a [`Span`] — `let left_right_arrow = punct::LeftRightArrow(sp)`
+///
+/// - Construction from multiple [`Span`] — `let left_right_arrow = punct::LeftRightArrow([sp, sp, sp])`
+///
+/// - Field access to its spans — `let spans = left_right_arrow.spans`
+///
+/// [Peeking]: parse/struct.ParseBuffer.html#method.peek
+/// [Parsing]: parse/struct.ParseBuffer.html#method.parse
+/// [Printing]: https://docs.rs/quote/0.6/quote/trait.ToTokens.html
+/// [`Span`]: struct.Span.html
+///
+/// # Example
+///
+/// ```edition2018
+/// use syn::{Expr, ExprParen, parenthesized};
+/// use syn::punctuated::Punctuated;
+/// use syn::parse::{Parse, ParseStream, Result};
+/// use syn::token::Paren;
+///
+/// mod punct {
+///     syn::custom_punctuation!(PathSeparator, </>);
+/// }
+///
+/// // (expr) </> (expr) </> (expr) ...
+/// struct PathSegments {
+///     segments: Punctuated<Expr, punct::PathSeparator>,
+/// }
+///
+/// impl Parse for PathSegments {
+///     fn parse(input: ParseStream) -> Result<Self> {
+///         let mut segments = Punctuated::new();
+///
+///         let la = input.lookahead1();
+///         if la.peek(Paren) {
+///             let content;
+///             let paren_token = parenthesized!(content in input);
+///             let expr = Box::new(content.parse()?);
+///             segments.push_value(Expr::Paren(ExprParen { attrs: vec![], paren_token, expr }));
+///         } else {
+///             return Err(la.error());
+///         }
+///
+///         while input.peek(punct::PathSeparator) {
+///             segments.push_punct(input.parse()?);
+///             let content;
+///             let paren_token = parenthesized!(content in input);
+///             let expr = Box::new(content.parse()?);
+///             segments.push_value(Expr::Paren(ExprParen { attrs: vec![], paren_token, expr }));
+///         }
+///
+///         Ok(PathSegments { segments })
+///     }
+/// }
+///
+/// let _: PathSegments = syn::parse_str(r#"("five") </> ("hundred")"#).unwrap();
+/// ```
+///
+#[macro_export(local_inner_macros)]
+macro_rules! custom_punctuation {
+    ($ident:ident, $($tt:tt)+) => {
+        pub struct $ident {
+            pub spans: [$crate::export::Span; punct_len!(lenient, $($tt)+)],
+        }
+
+        #[doc(hidden)]
+        #[allow(non_snake_case)]
+        pub fn $ident<__S: $crate::export::IntoSpans<[$crate::export::Span; punct_len!(lenient, $($tt)+)]>>(
+            spans: __S,
+        ) -> $ident {
+            let _punct_len = punct_len!(strict, $($tt)+);
+            $ident {
+                spans: $crate::export::IntoSpans::into_spans(spans)
+            }
+        }
+
+        impl $crate::export::Default for $ident {
+            fn default() -> Self {
+                $ident($crate::export::Span::call_site())
+            }
+        }
+
+        impl_parse_for_custom_punctuation!($ident, $($tt)+);
+        impl_to_tokens_for_custom_punctuation!($ident, $($tt)+);
+        impl_clone_for_custom_punctuation!($ident, $($tt)+);
+        impl_extra_traits_for_custom_punctuation!($ident, $($tt)+);
+    };
+}
+
+// Not public API.
+#[cfg(feature = "parsing")]
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! impl_parse_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {
+        impl $crate::token::CustomToken for $ident {
+            fn peek(cursor: $crate::buffer::Cursor) -> bool {
+                $crate::token::parsing::peek_punct(cursor, stringify_punct!($($tt)+))
+            }
+
+            fn display() -> &'static $crate::export::str {
+                my_concat!("`", stringify_punct!($($tt)+), "`")
+            }
+        }
+
+        impl $crate::parse::Parse for $ident {
+            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
+                let spans: [$crate::export::Span; punct_len!(lenient, $($tt)+)] =
+                    $crate::token::parsing::punct(input, stringify_punct!($($tt)+))?;
+                Ok($ident(spans))
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "parsing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_parse_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "printing")]
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! impl_to_tokens_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {
+        impl $crate::export::ToTokens for $ident {
+            fn to_tokens(&self, tokens: &mut $crate::export::TokenStream2) {
+                $crate::token::printing::punct(stringify_punct!($($tt)+), &self.spans, tokens)
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "printing"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_to_tokens_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "clone-impls")]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {
+        impl $crate::export::Copy for $ident {}
+
+        impl $crate::export::Clone for $ident {
+            fn clone(&self) -> Self {
+                *self
+            }
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "clone-impls"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_clone_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {};
+}
+
+// Not public API.
+#[cfg(feature = "extra-traits")]
+#[doc(hidden)]
+#[macro_export(local_inner_macros)]
+macro_rules! impl_extra_traits_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {
+        impl $crate::export::Debug for $ident {
+            fn fmt(&self, f: &mut $crate::export::Formatter) -> $crate::export::fmt::Result {
+                $crate::export::Formatter::write_str(f, stringify_punct!($($tt)+))
+            }
+        }
+
+        impl $crate::export::Eq for $ident {}
+
+        impl $crate::export::PartialEq for $ident {
+            fn eq(&self, _other: &Self) -> $crate::export::bool {
+                true
+            }
+        }
+
+        impl $crate::export::Hash for $ident {
+            fn hash<__H: $crate::export::Hasher>(&self, _state: &mut __H) {}
+        }
+    };
+}
+
+// Not public API.
+#[cfg(not(feature = "extra-traits"))]
+#[doc(hidden)]
+#[macro_export]
+macro_rules! impl_extra_traits_for_custom_punctuation {
+    ($ident: ident, $($tt:tt)+) => {};
+}
diff --git a/src/custom_token.rs b/src/custom_token.rs
deleted file mode 100644
index 3e9aba7..0000000
--- a/src/custom_token.rs
+++ /dev/null
@@ -1,555 +0,0 @@
-// Not public API.
-#[doc(hidden)]
-#[macro_export(local_inner_macros)]
-macro_rules! punct_len {
-    ($mode:ident, +)      => ( 1usize );
-    ($mode:ident, +=)     => ( 2usize );
-    ($mode:ident, &)      => ( 1usize );
-    ($mode:ident, &&)     => ( 2usize );
-    ($mode:ident, &=)     => ( 2usize );
-    ($mode:ident, @)      => ( 1usize );
-    ($mode:ident, !)      => ( 1usize );
-    ($mode:ident, ^)      => ( 1usize );
-    ($mode:ident, ^=)     => ( 2usize );
-    ($mode:ident, :)      => ( 1usize );
-    ($mode:ident, ::)     => ( 2usize );
-    ($mode:ident, ,)      => ( 1usize );
-    ($mode:ident, /)      => ( 1usize );
-    ($mode:ident, /=)     => ( 2usize );
-    ($mode:ident, .)      => ( 1usize );
-    ($mode:ident, ..)     => ( 2usize );
-    ($mode:ident, ...)    => ( 3usize );
-    ($mode:ident, ..=)    => ( 3usize );
-    ($mode:ident, =)      => ( 1usize );
-    ($mode:ident, ==)     => ( 2usize );
-    ($mode:ident, >=)     => ( 2usize );
-    ($mode:ident, >)      => ( 1usize );
-    ($mode:ident, <=)     => ( 2usize );
-    ($mode:ident, <)      => ( 1usize );
-    ($mode:ident, *=)     => ( 2usize );
-    ($mode:ident, !=)     => ( 2usize );
-    ($mode:ident, |)      => ( 1usize );
-    ($mode:ident, |=)     => ( 2usize );
-    ($mode:ident, ||)     => ( 2usize );
-    ($mode:ident, #)      => ( 1usize );
-    ($mode:ident, ?)      => ( 1usize );
-    ($mode:ident, ->)     => ( 2usize );
-    ($mode:ident, <-)     => ( 2usize );
-    ($mode:ident, %)      => ( 1usize );
-    ($mode:ident, %=)     => ( 2usize );
-    ($mode:ident, =>)     => ( 2usize );
-    ($mode:ident, ;)      => ( 1usize );
-    ($mode:ident, <<)     => ( 2usize );
-    ($mode:ident, <<=)    => ( 3usize );
-    ($mode:ident, >>)     => ( 2usize );
-    ($mode:ident, >>=)    => ( 3usize );
-    ($mode:ident, *)      => ( 1usize );
-    ($mode:ident, -)      => ( 1usize );
-    ($mode:ident, -=)     => ( 2usize );
-    ($mode:ident, ~)      => ( 1usize );
-    (lenient, $tt:tt)     => ( 0usize );
-    (strict, $tt:tt)      => ({ unexpected!($tt); 0usize });
-    ($mode:ident, $head:tt $($tail:tt)+) => ( punct_len!($mode, $head) $(+ punct_len!($mode, $tail))+ );
-}
-
-// Not public API.
-#[doc(hidden)]
-#[macro_export]
-macro_rules! unexpected {
-    () => {};
-}
-
-// Not public API.
-#[doc(hidden)]
-#[macro_export]
-macro_rules! stringify_punct {
-    ($($tt:tt)+) => ( concat!($(stringify!($tt)),+) );
-}
-
-// Not public API.
-// Without this, local_inner_macros breaks when looking for concat!
-#[doc(hidden)]
-#[macro_export]
-macro_rules! my_concat {
-    ($($tt:tt)*) => ( concat!($($tt)*) );
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-/// Define a type that supports parsing and printing a given identifier as if it
-/// were a keyword.
-///
-/// # Usage
-///
-/// As a convention, it is recommended that this macro be invoked within a
-/// module called `kw` or `keyword` and that the resulting parser be invoked
-/// with a `kw::` or `keyword::` prefix.
-///
-/// ```edition2018
-/// mod kw {
-///     syn::custom_keyword!(whatever);
-/// }
-/// ```
-///
-/// The generated syntax tree node supports the following operations just like
-/// any built-in keyword token.
-///
-/// - [Peeking] — `input.peek(kw::whatever)`
-///
-/// - [Parsing] — `input.parse::<kw::whatever>()?`
-///
-/// - [Printing] — `quote!( ... #whatever_token ... )`
-///
-/// - Construction from a [`Span`] — `let whatever_token = kw::whatever(sp)`
-///
-/// - Field access to its span — `let sp = whatever_token.span`
-///
-/// [Peeking]: parse/struct.ParseBuffer.html#method.peek
-/// [Parsing]: parse/struct.ParseBuffer.html#method.parse
-/// [Printing]: https://docs.rs/quote/0.6/quote/trait.ToTokens.html
-/// [`Span`]: https://docs.rs/proc-macro2/0.4/proc_macro2/struct.Span.html
-///
-/// # Example
-///
-/// This example parses input that looks like `bool = true` or `str = "value"`.
-/// The key must be either the identifier `bool` or the identifier `str`. If
-/// `bool`, the value may be either `true` or `false`. If `str`, the value may
-/// be any string literal.
-///
-/// The symbols `bool` and `str` are not reserved keywords in Rust so these are
-/// not considered keywords in the `syn::token` module. Like any other
-/// identifier that is not a keyword, these can be declared as custom keywords
-/// by crates that need to use them as such.
-///
-/// ```edition2018
-/// use syn::{LitBool, LitStr, Result, Token};
-/// use syn::parse::{Parse, ParseStream};
-///
-/// mod kw {
-///     syn::custom_keyword!(bool);
-///     syn::custom_keyword!(str);
-/// }
-///
-/// enum Argument {
-///     Bool {
-///         bool_token: kw::bool,
-///         eq_token: Token![=],
-///         value: LitBool,
-///     },
-///     Str {
-///         str_token: kw::str,
-///         eq_token: Token![=],
-///         value: LitStr,
-///     },
-/// }
-///
-/// impl Parse for Argument {
-///     fn parse(input: ParseStream) -> Result<Self> {
-///         let lookahead = input.lookahead1();
-///         if lookahead.peek(kw::bool) {
-///             Ok(Argument::Bool {
-///                 bool_token: input.parse::<kw::bool>()?,
-///                 eq_token: input.parse()?,
-///                 value: input.parse()?,
-///             })
-///         } else if lookahead.peek(kw::str) {
-///             Ok(Argument::Str {
-///                 str_token: input.parse::<kw::str>()?,
-///                 eq_token: input.parse()?,
-///                 value: input.parse()?,
-///             })
-///         } else {
-///             Err(lookahead.error())
-///         }
-///     }
-/// }
-/// ```
-#[macro_export(local_inner_macros)]
-macro_rules! custom_keyword {
-    ($ident:ident) => {
-        #[allow(non_camel_case_types)]
-        pub struct $ident {
-            pub span: $crate::export::Span,
-        }
-
-        #[doc(hidden)]
-        #[allow(non_snake_case)]
-        pub fn $ident<__S: $crate::export::IntoSpans<[$crate::export::Span; 1]>>(
-            span: __S,
-        ) -> $ident {
-            $ident {
-                span: $crate::export::IntoSpans::into_spans(span)[0],
-            }
-        }
-
-        impl $crate::export::Default for $ident {
-            fn default() -> Self {
-                $ident {
-                    span: $crate::export::Span::call_site(),
-                }
-            }
-        }
-
-        impl_parse_for_custom_keyword!($ident);
-        impl_to_tokens_for_custom_keyword!($ident);
-        impl_clone_for_custom_keyword!($ident);
-        impl_extra_traits_for_custom_keyword!($ident);
-    };
-}
-
-// Not public API.
-#[cfg(feature = "parsing")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_parse_for_custom_keyword {
-    ($ident:ident) => {
-        // For peek.
-        impl $crate::token::CustomToken for $ident {
-            fn peek(cursor: $crate::buffer::Cursor) -> $crate::export::bool {
-                if let Some((ident, _rest)) = cursor.ident() {
-                    ident == stringify!($ident)
-                } else {
-                    false
-                }
-            }
-
-            fn display() -> &'static $crate::export::str {
-                concat!("`", stringify!($ident), "`")
-            }
-        }
-
-        impl $crate::parse::Parse for $ident {
-            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
-                input.step(|cursor| {
-                    if let $crate::export::Some((ident, rest)) = cursor.ident() {
-                        if ident == stringify!($ident) {
-                            return $crate::export::Ok(($ident { span: ident.span() }, rest));
-                        }
-                    }
-                    $crate::export::Err(cursor.error(concat!(
-                        "expected `",
-                        stringify!($ident),
-                        "`"
-                    )))
-                })
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "parsing"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_parse_for_custom_keyword {
-    ($ident:ident) => {};
-}
-
-// Not public API.
-#[cfg(feature = "printing")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_to_tokens_for_custom_keyword {
-    ($ident:ident) => {
-        impl $crate::export::ToTokens for $ident {
-            fn to_tokens(&self, tokens: &mut $crate::export::TokenStream2) {
-                let ident = $crate::Ident::new(stringify!($ident), self.span);
-                $crate::export::TokenStreamExt::append(tokens, ident);
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "printing"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_to_tokens_for_custom_keyword {
-    ($ident:ident) => {};
-}
-
-// Not public API.
-#[cfg(feature = "clone-impls")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_clone_for_custom_keyword {
-    ($ident:ident) => {
-        impl $crate::export::Copy for $ident {}
-
-        impl $crate::export::Clone for $ident {
-            fn clone(&self) -> Self {
-                *self
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "clone-impls"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_clone_for_custom_keyword {
-    ($ident:ident) => {};
-}
-
-// Not public API.
-#[cfg(feature = "extra-traits")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_extra_traits_for_custom_keyword {
-    ($ident:ident) => {
-        impl $crate::export::Debug for $ident {
-            fn fmt(&self, f: &mut $crate::export::Formatter) -> $crate::export::fmt::Result {
-                $crate::export::Formatter::write_str(f, stringify!($ident))
-            }
-        }
-
-        impl $crate::export::Eq for $ident {}
-
-        impl $crate::export::PartialEq for $ident {
-            fn eq(&self, _other: &Self) -> $crate::export::bool {
-                true
-            }
-        }
-
-        impl $crate::export::Hash for $ident {
-            fn hash<__H: $crate::export::Hasher>(&self, _state: &mut __H) {}
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "extra-traits"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_extra_traits_for_custom_keyword {
-    ($ident:ident) => {};
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
-/// Define a type that supports parsing and printing a multi-character symbol
-/// as if it were a token.
-///
-/// # Usage
-///
-/// As a convention, it is recommended that this macro be invoked within a
-/// module called `punct` or `punctuation` and that the resulting parser be invoked
-/// with a `punct::` or `punctuation::` prefix.
-///
-/// ```edition2018
-/// mod punct {
-///     syn::custom_punctuation!(LeftRightArrow, <=>);
-/// }
-/// ```
-///
-/// The generated syntax tree node supports the following operations just like
-/// any built-in punctuation token.
-///
-/// - [Peeking] — `input.peek(punct::LeftRightArrow)`
-///
-/// - [Parsing] — `input.parse::<punct::LeftRightArrow>()?`
-///
-/// - [Printing] — `quote!( ... #left_right_arrow ... )`
-///
-/// - Construction from a [`Span`] — `let left_right_arrow = punct::LeftRightArrow(sp)`
-///
-/// - Construction from multiple [`Span`] — `let left_right_arrow = punct::LeftRightArrow([sp, sp, sp])`
-///
-/// - Field access to its spans — `let spans = left_right_arrow.spans`
-///
-/// [Peeking]: parse/struct.ParseBuffer.html#method.peek
-/// [Parsing]: parse/struct.ParseBuffer.html#method.parse
-/// [Printing]: https://docs.rs/quote/0.6/quote/trait.ToTokens.html
-/// [`Span`]: struct.Span.html
-///
-/// # Example
-///
-/// ```edition2018
-/// use syn::{Expr, ExprParen, parenthesized};
-/// use syn::punctuated::Punctuated;
-/// use syn::parse::{Parse, ParseStream, Result};
-/// use syn::token::Paren;
-///
-/// mod punct {
-///     syn::custom_punctuation!(PathSeparator, </>);
-/// }
-///
-/// // (expr) </> (expr) </> (expr) ...
-/// struct PathSegments {
-///     segments: Punctuated<Expr, punct::PathSeparator>,
-/// }
-///
-/// impl Parse for PathSegments {
-///     fn parse(input: ParseStream) -> Result<Self> {
-///         let mut segments = Punctuated::new();
-///
-///         let la = input.lookahead1();
-///         if la.peek(Paren) {
-///             let content;
-///             let paren_token = parenthesized!(content in input);
-///             let expr = Box::new(content.parse()?);
-///             segments.push_value(Expr::Paren(ExprParen { attrs: vec![], paren_token, expr }));
-///         } else {
-///             return Err(la.error());
-///         }
-///
-///         while input.peek(punct::PathSeparator) {
-///             segments.push_punct(input.parse()?);
-///             let content;
-///             let paren_token = parenthesized!(content in input);
-///             let expr = Box::new(content.parse()?);
-///             segments.push_value(Expr::Paren(ExprParen { attrs: vec![], paren_token, expr }));
-///         }
-///
-///         Ok(PathSegments { segments })
-///     }
-/// }
-///
-/// let _: PathSegments = syn::parse_str(r#"("five") </> ("hundred")"#).unwrap();
-/// ```
-///
-#[macro_export(local_inner_macros)]
-macro_rules! custom_punctuation {
-    ($ident:ident, $($tt:tt)+) => {
-        pub struct $ident {
-            pub spans: [$crate::export::Span; punct_len!(lenient, $($tt)+)],
-        }
-
-        #[doc(hidden)]
-        #[allow(non_snake_case)]
-        pub fn $ident<__S: $crate::export::IntoSpans<[$crate::export::Span; punct_len!(lenient, $($tt)+)]>>(
-            spans: __S,
-        ) -> $ident {
-            let _punct_len = punct_len!(strict, $($tt)+);
-            $ident {
-                spans: $crate::export::IntoSpans::into_spans(spans)
-            }
-        }
-
-        impl $crate::export::Default for $ident {
-            fn default() -> Self {
-                $ident($crate::export::Span::call_site())
-            }
-        }
-
-        impl_parse_for_custom_punctuation!($ident, $($tt)+);
-        impl_to_tokens_for_custom_punctuation!($ident, $($tt)+);
-        impl_clone_for_custom_punctuation!($ident, $($tt)+);
-        impl_extra_traits_for_custom_punctuation!($ident, $($tt)+);
-    };
-}
-
-// Not public API.
-#[cfg(feature = "parsing")]
-#[doc(hidden)]
-#[macro_export(local_inner_macros)]
-macro_rules! impl_parse_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {
-        impl $crate::token::CustomToken for $ident {
-            fn peek(cursor: $crate::buffer::Cursor) -> bool {
-                $crate::token::parsing::peek_punct(cursor, stringify_punct!($($tt)+))
-            }
-
-            fn display() -> &'static $crate::export::str {
-                my_concat!("`", stringify_punct!($($tt)+), "`")
-            }
-        }
-
-        impl $crate::parse::Parse for $ident {
-            fn parse(input: $crate::parse::ParseStream) -> $crate::parse::Result<$ident> {
-                let spans: [$crate::export::Span; punct_len!(lenient, $($tt)+)] =
-                    $crate::token::parsing::punct(input, stringify_punct!($($tt)+))?;
-                Ok($ident(spans))
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "parsing"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_parse_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {};
-}
-
-// Not public API.
-#[cfg(feature = "printing")]
-#[doc(hidden)]
-#[macro_export(local_inner_macros)]
-macro_rules! impl_to_tokens_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {
-        impl $crate::export::ToTokens for $ident {
-            fn to_tokens(&self, tokens: &mut $crate::export::TokenStream2) {
-                $crate::token::printing::punct(stringify_punct!($($tt)+), &self.spans, tokens)
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "printing"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_to_tokens_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {};
-}
-
-// Not public API.
-#[cfg(feature = "clone-impls")]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_clone_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {
-        impl $crate::export::Copy for $ident {}
-
-        impl $crate::export::Clone for $ident {
-            fn clone(&self) -> Self {
-                *self
-            }
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "clone-impls"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_clone_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {};
-}
-
-// Not public API.
-#[cfg(feature = "extra-traits")]
-#[doc(hidden)]
-#[macro_export(local_inner_macros)]
-macro_rules! impl_extra_traits_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {
-        impl $crate::export::Debug for $ident {
-            fn fmt(&self, f: &mut $crate::export::Formatter) -> $crate::export::fmt::Result {
-                $crate::export::Formatter::write_str(f, stringify_punct!($($tt)+))
-            }
-        }
-
-        impl $crate::export::Eq for $ident {}
-
-        impl $crate::export::PartialEq for $ident {
-            fn eq(&self, _other: &Self) -> $crate::export::bool {
-                true
-            }
-        }
-
-        impl $crate::export::Hash for $ident {
-            fn hash<__H: $crate::export::Hasher>(&self, _state: &mut __H) {}
-        }
-    };
-}
-
-// Not public API.
-#[cfg(not(feature = "extra-traits"))]
-#[doc(hidden)]
-#[macro_export]
-macro_rules! impl_extra_traits_for_custom_punctuation {
-    ($ident: ident, $($tt:tt)+) => {};
-}
diff --git a/src/lib.rs b/src/lib.rs
index e119192..ee867be 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -538,7 +538,8 @@
 #[doc(hidden)]
 pub mod export;
 
-mod custom_token;
+mod custom_keyword;
+mod custom_punctuation;
 
 #[cfg(feature = "parsing")]
 mod lookahead;