tibbletime3:

#### General -------------------------------------------------------------------

# yearqtr is more complicated. Need to switch the position of quarter/year
# and convert the quarter to a numeric
validate_side.yearqtr <- function(x) {

  x <- as.character(x)
  x_list <- stringr::str_split(
    string = x,
    pattern = " ",
    simplify = TRUE
  )

  replace_char_quarter <- function(x) {
    switch(x, "Q1" = 1, "Q2" = 2, "Q3" = 3, "Q4" = 4)
  }

  year    <- x_list[1, 1]
  quarter <- x_list[1, 2]
  quarter <- replace_char_quarter(quarter)

  paste0(year, "-", quarter)
}

floor_date_time.yearqtr <- function(x, unit = "seconds") {
  as.yearqtr(floor_date_time(zoo::as.Date(x), unit))
}

ceiling_date_time.yearqtr <- function(x, unit = "seconds") {
  as.yearqtr(ceiling_date_time(zoo::as.Date(x), unit))
}

#### create_series -------------------------------------------------------------

lookup_seq_fun.yearqtr <- function(x) {
  seq.yearqtr
}

#### parse_period --------------------------------------------------------------

assert_period_matches_index_class.yearqtr <- function(x, period) {
  assertthat::assert_that(
    period %in% c("year", "quarter"),
    msg = "Only year and quarter periods are allowed for an index of class yearqtr"
  )
}

#### parse_time_formula --------------------------------------------------------

lookup_defaults.yearqtr <- function(index, side = "lhs") {
  switch(side,
         "lhs" = list(y = 1970, q = 01),
         "rhs" = list(y = 1970, q = 04))
}

list_to_datetime.yearqtr <- function(index, tf_side, ...) {
  yearqtr_string <- paste0(tf_side$y, "-", tf_side$q)
  zoo::as.yearqtr(yearqtr_string)
}

#### time_collapse -------------------------------------------------------------

# Same problem as yearmon, code is generic enough that this works
dispatch_max_collapse.yearqtr <- dispatch_max_collapse.yearmon

#### time_group ----------------------------------------------------------------

coerce_start_date.yearqtr <- function(x, start_date) {
  zoo::as.yearqtr(start_date)
}