1 files changed, 190 insertions, 0 deletions
diff --git a/third_party/rust/minimal-lexical/src/heapvec.rs b/third_party/rust/minimal-lexical/src/heapvec.rs
new file mode 100644
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+++ b/third_party/rust/minimal-lexical/src/heapvec.rs
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+//! Simple heap-allocated vector.
+
+#![cfg(feature = "alloc")]
+#![doc(hidden)]
+
+use crate::bigint;
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+use core::{cmp, ops};
+#[cfg(feature = "std")]
+use std::vec::Vec;
+
+/// Simple heap vector implementation.
+#[derive(Clone)]
+pub struct HeapVec {
+    /// The heap-allocated buffer for the elements.
+    data: Vec<bigint::Limb>,
+}
+
+#[allow(clippy::new_without_default)]
+impl HeapVec {
+    /// Construct an empty vector.
+    #[inline]
+    pub fn new() -> Self {
+        Self {
+            data: Vec::with_capacity(bigint::BIGINT_LIMBS),
+        }
+    }
+
+    /// Construct a vector from an existing slice.
+    #[inline]
+    pub fn try_from(x: &[bigint::Limb]) -> Option<Self> {
+        let mut vec = Self::new();
+        vec.try_extend(x)?;
+        Some(vec)
+    }
+
+    /// Sets the length of a vector.
+    ///
+    /// This will explicitly set the size of the vector, without actually
+    /// modifying its buffers, so it is up to the caller to ensure that the
+    /// vector is actually the specified size.
+    ///
+    /// # Safety
+    ///
+    /// Safe as long as `len` is less than `self.capacity()` and has been initialized.
+    #[inline]
+    pub unsafe fn set_len(&mut self, len: usize) {
+        debug_assert!(len <= bigint::BIGINT_LIMBS);
+        unsafe { self.data.set_len(len) };
+    }
+
+    /// The number of elements stored in the vector.
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.data.len()
+    }
+
+    /// If the vector is empty.
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    /// The number of items the vector can hold.
+    #[inline]
+    pub fn capacity(&self) -> usize {
+        self.data.capacity()
+    }
+
+    /// Append an item to the vector.
+    #[inline]
+    pub fn try_push(&mut self, value: bigint::Limb) -> Option<()> {
+        self.data.push(value);
+        Some(())
+    }
+
+    /// Remove an item from the end of the vector and return it, or None if empty.
+    #[inline]
+    pub fn pop(&mut self) -> Option<bigint::Limb> {
+        self.data.pop()
+    }
+
+    /// Copy elements from a slice and append them to the vector.
+    #[inline]
+    pub fn try_extend(&mut self, slc: &[bigint::Limb]) -> Option<()> {
+        self.data.extend_from_slice(slc);
+        Some(())
+    }
+
+    /// Try to resize the buffer.
+    ///
+    /// If the new length is smaller than the current length, truncate
+    /// the input. If it's larger, then append elements to the buffer.
+    #[inline]
+    pub fn try_resize(&mut self, len: usize, value: bigint::Limb) -> Option<()> {
+        self.data.resize(len, value);
+        Some(())
+    }
+
+    // HI
+
+    /// Get the high 64 bits from the vector.
+    #[inline(always)]
+    pub fn hi64(&self) -> (u64, bool) {
+        bigint::hi64(&self.data)
+    }
+
+    // FROM
+
+    /// Create StackVec from u64 value.
+    #[inline(always)]
+    pub fn from_u64(x: u64) -> Self {
+        bigint::from_u64(x)
+    }
+
+    // MATH
+
+    /// Normalize the integer, so any leading zero values are removed.
+    #[inline]
+    pub fn normalize(&mut self) {
+        bigint::normalize(self)
+    }
+
+    /// Get if the big integer is normalized.
+    #[inline]
+    pub fn is_normalized(&self) -> bool {
+        bigint::is_normalized(self)
+    }
+
+    /// AddAssign small integer.
+    #[inline]
+    pub fn add_small(&mut self, y: bigint::Limb) -> Option<()> {
+        bigint::small_add(self, y)
+    }
+
+    /// MulAssign small integer.
+    #[inline]
+    pub fn mul_small(&mut self, y: bigint::Limb) -> Option<()> {
+        bigint::small_mul(self, y)
+    }
+}
+
+impl PartialEq for HeapVec {
+    #[inline]
+    #[allow(clippy::op_ref)]
+    fn eq(&self, other: &Self) -> bool {
+        use core::ops::Deref;
+        self.len() == other.len() && self.deref() == other.deref()
+    }
+}
+
+impl Eq for HeapVec {
+}
+
+impl cmp::PartialOrd for HeapVec {
+    #[inline]
+    fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
+        Some(bigint::compare(self, other))
+    }
+}
+
+impl cmp::Ord for HeapVec {
+    #[inline]
+    fn cmp(&self, other: &Self) -> cmp::Ordering {
+        bigint::compare(self, other)
+    }
+}
+
+impl ops::Deref for HeapVec {
+    type Target = [bigint::Limb];
+    #[inline]
+    fn deref(&self) -> &[bigint::Limb] {
+        &self.data
+    }
+}
+
+impl ops::DerefMut for HeapVec {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut [bigint::Limb] {
+        &mut self.data
+    }
+}
+
+impl ops::MulAssign<&[bigint::Limb]> for HeapVec {
+    #[inline]
+    fn mul_assign(&mut self, rhs: &[bigint::Limb]) {
+        bigint::large_mul(self, rhs).unwrap();
+    }
+}