Extracts a strided interval of the specified size from a containing interval.

This function is primarily for use by DimExpression::SizedInterval.

The precise definition is as follows:

If start == kImplicit:

• Sets adjusted_start to orig.interval.inclusive_min() if stride > 0, or orig.interval.inclusive_max() otherwise.

• Sets implicit_lower = orig.implicit_lower().

Otherwise (if start != kImplicit):

Sets adjusted_start = start. Sets implicit_lower = false.

Sets new_inclusive_min = adjusted_start / stride (rounding towards zero).

If size != kImplicit:

• Sets new_size = size.

Otherwise (if size == kImplicit):

• Sets new_size to the maximum positive integer such that Contains(orig.interval, adjusted_start + stride * (new_size - 1)), or 0 if there is no such integer (can only occur if orig.size() == 0).

If stride < 0, swaps implicit_lower and implicit_upper.

Sets new_interval to be the interval starting at new_inclusive_min with a size of new_size.

Parameters:¶

OptionallyImplicitIndexInterval orig¶

The original interval from which to extract a strided slice.

Index start¶

The index within orig corresponding to the inclusive_min value in the result interval. If equal to kImplicit, the lower (if stride > 0) or upper (if stride < 0) bound of orig is used.

Index size¶

Specifies the size of the result interval.

Index stride¶

Specifies the stride value.

Returns:¶

{{new_interval, implicit_lower, implicit_upper}, adjusted_start}.

Error absl::StatusCode::kInvalidArgument:¶

if stride == 0 or stride == std::numeric_limits<Index>::min().

Error absl::StatusCode::kInvalidArgument:¶

if size < 0.

Error absl::StatusCode::kOutOfRange:¶

if new_size > 0 and orig does not contain adjusted_start + stride * (new_size - 1) (implicit bounds of orig are not constraints).