return expr

src/parser_api.rs

@@ -3,22 +3,22 @@ use {
     SyntaxKind::{self, ERROR},
 };
 
-pub(crate) struct TokenSet {
-    pub tokens: &'static [SyntaxKind],
+#[derive(Clone, Copy)]
+pub(crate) struct TokenSet(pub(crate) u128);
+fn mask(kind: SyntaxKind) -> u128 {
+    1u128 << (kind as usize)
 }
 
 impl TokenSet {
     pub fn contains(&self, kind: SyntaxKind) -> bool {
-        self.tokens.contains(&kind)
+        self.0 & mask(kind) != 0
     }
 }
 
 #[macro_export]
 macro_rules! token_set {
     ($($t:ident),*) => {
-        TokenSet {
-            tokens: &[$($t),*],
-        }
+        TokenSet($(1u128 << ($t as usize))|*)
     };
 
     ($($t:ident),* ,) => {
@@ -26,6 +26,17 @@ macro_rules! token_set {
     };
 }
 
+#[macro_export]
+macro_rules! token_set_union {
+    ($($ts:expr),*) => {
+        TokenSet($($ts.0)|*)
+    };
+
+    ($($ts:expr),* ,) => {
+        token_set_union!($($ts),*)
+    };
+}
+
 /// `Parser` struct provides the low-level API for
 /// navigating through the stream of tokens and
 /// constructing the parse tree. The actual parsing