datahike.pg.datetime.format — org.replikativ/pg-datahike 0.1.362

to_char over timestamps, timestamptz, dates and intervals -- a port of formatting.c's DCH side (parse_format, DCH_keywords / DCH_suff, DCH_to_char), PostgreSQL 17.

Ported rather than mapped onto java.time patterns, because the two languages only look alike: PostgreSQL matches a keyword by the FIRST table entry that prefixes the input (HH12 before HH, DDD before DD), lets FM/TM prefix and TH/th/SP follow any keyword, pads a month or day NAME to nine characters, counts centuries so that 20 is 1901-2000, numbers BC years from 1 (astronomical year 0 is 1 BC), and prints a negative interval field with an extra digit of width.

The input side (to_date / to_timestamp, DCH_from_char) is not here.

do-to-timestamp clj

(do-to-timestamp input fmt)

do_to_timestamp: the input parsed by fmt into {:year :mon :mday :hour :min :sec :fsec :tz (seconds WEST, or nil) :ff}.

from-char clj

(from-char in fmt)

DCH_from_char, non-standard mode: the TmFromChar fields as a map.

interval-fields clj

(interval-fields months days micros)

interval2itm: years and months from the month count, days as they are, and the time split into hours (unbounded), minutes, seconds and microseconds, each carrying the sign.

parse-format clj

(parse-format fmt)

parse_format for the DCH flag: a vector of nodes, either {:key id :suffix #{…}} for a keyword or {:text s} for literal output.

timestamp-fields clj

(timestamp-fields t)

A timestamp's fields: its wall clock as it stands.

timestamptz-fields clj

(timestamptz-fields i zone)

A timestamptz's fields: its wall clock in zone, with that zone's offset and abbreviation at the instant.

to-char clj

(to-char tm interval? fmt)

DCH_to_char over tm, a map of the broken-down value: :year (astronomical) :mon :mday :hour :min :sec :usec, plus :yday and :wday for a timestamp, and :gmtoff / :tzn for a timestamptz. interval? selects the interval rules.

to-date clj

(to-date input fmt)

to_date(text, text).

to-timestamp clj

(to-timestamp input fmt zone)

to_timestamp(text, text): the parsed wall clock placed by the zone the input gave, else by zone (the session's), then rounded to the FFn precision if one was given (AdjustTimestampForTypmod, which rounds half away from zero measured from PostgreSQL's 2000-01-01 epoch).