Method adjust_indices

crates/vm/src/sliceable.rs:372–399

Equivalent to PySlice_AdjustIndices Convert for usage in indexing the underlying rust collections. Called *after __index__ has been called on the Slice which might mutate the collection.

(&self, len: usize)

    /// Convert for usage in indexing the underlying rust collections. Called *after*
    /// __index__ has been called on the Slice which might mutate the collection.
    pub fn adjust_indices(&self, len: usize) -> (Range<usize>, isize, usize) {
        if len == 0 {
            return (0..0, self.step, 0);
        }
        let range = if self.step.is_negative() {
            let stop = if self.stop == -1 {
                len
            } else {
                self.stop.saturating_add(1).saturated_at(len)
            };
            let start = if self.start == -1 {
                len
            } else {
                self.start.saturating_add(1).saturated_at(len)
            };
            stop..start
        } else {
            self.start.saturated_at(len)..self.stop.saturated_at(len)
        };

        let (range, slice_len) = if range.start >= range.end {
            (range.start..range.start, 0)
        } else {
            let slice_len = (range.end - range.start - 1) / self.step.unsigned_abs() + 1;
            (range, slice_len)
        };
        (range, self.step, slice_len)
    }

    pub fn iter(&self, len: usize) -> SaturatedSliceIter {
        SaturatedSliceIter::new(self, len)