Extracts a strided closed interval from a containing interval.

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

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.

If stop == kImplicit:

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

• Sets implicit_upper = orig.implicit_upper().

Otherwise (if stop != kImplicit):

• Sets adjusted_stop = stop.

• Sets implicit_upper = false.

If stride > 0:

• Sets adjusted_interval to [adjusted_start, adjusted_stop].

Otherwise (if stride < 0):

• Sets adjusted_interval to [adjusted_stop, adjusted_start].

• Swaps implicit_lower and implicit_upper.

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

If adjusted_stop * sign(stride) == kInfIndex:

• Sets new_size = kInfIndex + 1 - new_inclusive_min.

Otherwise:

• Sets new_size to the maximum positive integer such that adjusted_start + stride * (new_size - 1) is contained in adjusted_interval.

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 stop¶

Specifies the inclusive stop index within orig. If equal to kImplicit, the upper (if stride > 0) or lower (if stride < 0) bound of orig is used.

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 adjusted_interval is not a valid interval.

Error absl::StatusCode::kOutOfRange:¶

if adjusted_interval is not contained within orig (implicit bounds of orig do not constrain adjusted_interval).