Changes in version 1.0.0.9000                      

Features

  - New phint_unoverlap() resolves overlaps across elements of a
    <phinterval> vector by trimming each element against all preceding
    elements.
    
      - An optional priority argument groups elements by priority, so
        that lower-priority elements are trimmed against higher-priority
        elements instead of by row-order.
    
      - priority_order controls whether lower ("asc") or higher ("desc")
        priority values are processed first, or whether groups are
        processed in order of first appearance ("appearance").
    
      - within_priority controls whether overlaps within the same
        priority group are resolved sequentially ("sequential") or left
        as-is ("keep").
    
      - na_propagate controls whether NA elements propagate to
        subsequent elements or lower-priority groups.

  - New phint_has_overlaps() returns a logical vector indicating which
    elements of a <phinterval> vector overlap with a preceding element.
    Accepts the same arguments as phint_unoverlap().
    
      - New phint_any_overlaps() is a fast scalar equivalent to
        any(phint_has_overlaps(...), na.rm = TRUE).

  - New phint_cumunion(), phint_cumintersect(),
    phint_symmetric_setdiff() to complete the family of set-operations.
    
      - phint_cumunion() and phint_cumintersect() take the cumulative
        union and intersection of a phinterval respectively.
    
      - phint_symmetric_setdiff() takes the symmetric set-difference of
        two phintervals.

  - New phint_flatten() returns all spans or gaps within an entire
    phinterval vector as a vector of intervals.
    
      - New datetime_flatten() returns spans or gaps within a vector of
        spans defined by start and end points (see also
        datetime_squash()).

  - New is_span() and is_disjoint() to complement is_hole().
    
      - is_span() and is_disjoint() test whether each element of a
        phinterval is contiguous or disjoint respectively.

  - phint_sift() now keeps or discards spans with lengths in
    [min_length, max_length], instead of discarding instantaneous spans
    only.
    
      - The previous version of phint_sift() was re-named to
        phint_discard_instants().

Bug fixes

  - phint_setdiff() no longer returns a malformed phinterval when phint2
    contains instants (#3).

  - phint_invert() no longer returns a malformed phinterval when phint
    contains instants (#9).

Breaking changes

  - phint_unnest() now always returns a dataframe with columns key,
    start, end, and size, instead of optionally including a size column.

The keep_size argument has been removed from phint_unnest() and the
function signature has been revised:

# Old Usage
phint_unnest(phint, hole_to = c("drop", "na"), keep_size = FALSE, key = NULL)

# New Usage
phint_unnest(phint, key = NULL, hole_to = c("na", "drop"))

  - phint_squash() and datetime_squash() have been split into two
    functions (#13).
    
      - phint_squash() and datetime_squash() now always squash intervals
        into a length-1 <phinterval>.
    
      - phint_squash_by() and datetime_squash_by() squash intervals
        within groups defined by the by argument.
    
      - The order_by argument of phint_squash_by() and
        datetime_squash_by() now defaults to TRUE, to match the behavior
        of dplyr::group_by().
    
      - The na.rm argument of the squash functions has been renamed to
        na_rm (#19).

The return type of the *_squash() variants is now always a scalar
<phinterval> vector, meaning it is safe to use within
dplyr::summarize(). This includes cases where the phint argument of
phint_squash() or the start, end arguments of datetime_squash() are
empty as the empty_to = "empty" option has been removed from the
empty_to argument.

The return type of the *_squash_by() variants is now always a tibble()
with columns by and phint. Additionally, the keep_by argument has been
removed from these variants.

# Old Usage
phint_squash(
  phint,
  by = NULL,
  na.rm = TRUE,
  empty_to = c("hole", "na", "empty"),
  order_by = FALSE,
  keep_by = FALSE
)

# New Usage
phint_squash(
  phint,
  na_rm = TRUE,
  empty_to = c("hole", "na")
)

phint_squash_by(
  phint,
  by,
  na_rm = TRUE,
  empty_to = c("hole", "na"),
  order_by = TRUE
)

  - phint_sift() now has additional arguments min_length, max_length,
    and action.
    
      - The previous version of phint_sift() (usage phint_sift(phint))
        was re-named to phint_discard_instants().
    
      - Calling phint_sift(phint) without additional arguments now
        raises an error.

                 Changes in version 1.0.0 (2026-02-03)                  

  - Initial CRAN submission.