refactor: minor changes for fixing build in 32-bits targets.

Don't use bit arrays with `u64` as the underlying type, as this is not supported in 32-bits platforms, use `usize` instead.

lib/src/compiler/atoms/quality.rs

@@ -20,7 +20,7 @@ where
     best_quality: i32,
     best_range: Option<Range<usize>>,
     queue: VecDeque<(usize, u8, u8, i32)>,
-    bytes_present: BitArray<[u64; 4]>,
+    bytes_present: BitArray<[usize; 256 / usize::BITS as usize]>,
     byte_mask_iter: I,
 }
 
@@ -483,7 +483,7 @@ mod test {
             [0x01, 0x02, 0x03, 0x04].iter(),
             [0xff, 0xff, 0x00, 0xff].iter(),
         );
-        
+
         assert!(q_00000001 > q_00000000);
         assert!(q_00000001 > q_000001);
         assert!(q_000001 > q_0001);

lib/src/re/thompson/instr.rs

@@ -85,8 +85,12 @@ impl Display for SplitId {
 }
 
 impl SplitId {
+    /// Number of bits in an SplitId.
     pub const BITS: usize = 13;
 
+    /// Maximum SplitId.
+    pub const MAX: usize = (1 << SplitId::BITS) - 1;
+
     #[inline]
     pub fn to_le_bytes(self) -> [u8; size_of::<Self>()] {
         self.0.to_le_bytes()
@@ -103,7 +107,7 @@ impl SplitId {
     #[inline]
     pub fn add(self, amount: u16) -> Option<Self> {
         let sum = self.0.checked_add(amount)?;
-        if sum >= 1 << Self::BITS {
+        if sum as usize > Self::MAX {
             return None;
         }
         Some(Self(sum))

lib/src/re/thompson/pikevm.rs

@@ -250,7 +250,8 @@ pub struct EpsilonClosureState {
     /// This bit array has one bit per possible value of SplitId. If the
     /// split instruction with SplitId = N is executed, the N-th bit in the
     /// array is set to 1.
-    executed_splits: BitArray<[u64; (1 << SplitId::BITS) / 64]>,
+    executed_splits:
+        BitArray<[usize; SplitId::MAX.div_ceil(usize::BITS as usize)]>,
     /// Indicates whether the `executed_splits` bit array needs to be
     /// cleared during the next call to [`EpsilonClosureState::executed`].
     dirty: bool,

lib/src/re/thompson/tests.rs

@@ -4,6 +4,7 @@ use pretty_assertions::assert_eq;
 use crate::compiler::Atom;
 use crate::re;
 use crate::re::bitmapset::BitmapSet;
+use crate::re::thompson::instr::SplitId;
 use crate::re::{BckCodeLoc, FwdCodeLoc};
 use crate::types::Regexp;
 
@@ -1455,3 +1456,13 @@ fn re_atoms() {
         50
     );
 }
+
+#[test]
+fn split_id() {
+    assert_eq!(SplitId::BITS, 13);
+    assert_eq!(SplitId::MAX, 8191);
+    assert!(SplitId::default()
+        .add(SplitId::MAX as u16)
+        .and_then(|id| id.add(1))
+        .is_none())
+}