43 lines
967 B
Rust
43 lines
967 B
Rust
//! A bit-set of `SyntaxKind`s.
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use crate::SyntaxKind;
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/// A bit-set of `SyntaxKind`s
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#[derive(Clone, Copy)]
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pub(crate) struct TokenSet(u128);
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impl TokenSet {
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pub(crate) const EMPTY: TokenSet = TokenSet(0);
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pub(crate) const fn new(kinds: &[SyntaxKind]) -> TokenSet {
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let mut res = 0u128;
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let mut i = 0;
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while i < kinds.len() {
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res |= mask(kinds[i]);
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i += 1
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}
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TokenSet(res)
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}
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pub(crate) const fn union(self, other: TokenSet) -> TokenSet {
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TokenSet(self.0 | other.0)
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}
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pub(crate) const fn contains(&self, kind: SyntaxKind) -> bool {
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self.0 & mask(kind) != 0
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}
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}
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const fn mask(kind: SyntaxKind) -> u128 {
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1u128 << (kind as usize)
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}
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#[test]
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fn token_set_works_for_tokens() {
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use crate::SyntaxKind::*;
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let ts = TokenSet::new(&[EOF, SHEBANG]);
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assert!(ts.contains(EOF));
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assert!(ts.contains(SHEBANG));
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assert!(!ts.contains(PLUS));
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}
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