build(rust): vendor rnix parser crate

third_party/crates/rnix-0.14.0/src/token_set.rs

@@ -0,0 +1,86 @@
+use std::ops;
+
+use crate::SyntaxKind;
+
+/// A bit-set of `SyntaxKind`s
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct TokenSet(u128);
+
+impl TokenSet {
+    #[allow(dead_code)]
+    pub(crate) const EMPTY: TokenSet = TokenSet(0);
+
+    pub(crate) const fn new(kind: SyntaxKind) -> TokenSet {
+        TokenSet(mask(kind))
+    }
+
+    pub(crate) const fn from_slice(kinds: &[SyntaxKind]) -> TokenSet {
+        let mut res = 0u128;
+        let mut i = 0;
+        while i < kinds.len() {
+            res |= mask(kinds[i]);
+            i += 1
+        }
+        TokenSet(res)
+    }
+
+    pub(crate) const fn union(self, other: TokenSet) -> TokenSet {
+        TokenSet(self.0 | other.0)
+    }
+
+    pub(crate) const fn contains(&self, kind: SyntaxKind) -> bool {
+        self.0 & mask(kind) != 0
+    }
+}
+
+const fn mask(kind: SyntaxKind) -> u128 {
+    1u128 << (kind as usize)
+}
+
+impl ops::BitOr for SyntaxKind {
+    type Output = TokenSet;
+
+    fn bitor(self, rhs: Self) -> Self::Output {
+        TokenSet(mask(self) | mask(rhs))
+    }
+}
+
+impl ops::BitOr<SyntaxKind> for TokenSet {
+    type Output = TokenSet;
+
+    fn bitor(self, rhs: SyntaxKind) -> Self::Output {
+        self.union(TokenSet(mask(rhs)))
+    }
+}
+
+impl ops::BitOr<TokenSet> for SyntaxKind {
+    type Output = TokenSet;
+
+    fn bitor(self, rhs: TokenSet) -> Self::Output {
+        TokenSet(mask(self)).union(rhs)
+    }
+}
+
+impl ops::BitOr<TokenSet> for TokenSet {
+    type Output = TokenSet;
+
+    fn bitor(self, rhs: TokenSet) -> Self::Output {
+        self.union(rhs)
+    }
+}
+
+impl ops::BitOr<SyntaxKind> for () {
+    type Output = TokenSet;
+
+    fn bitor(self, rhs: SyntaxKind) -> Self::Output {
+        TokenSet::new(rhs)
+    }
+}
+
+impl ops::BitOr<()> for SyntaxKind {
+    type Output = TokenSet;
+
+    fn bitor(self, (): ()) -> Self::Output {
+        TokenSet::new(self)
+    }
+}