jq duration helpers

duration.jq

# "01:02:03.45" -> 3723.45
def from_duration:
  ( reduce (split(":") | reverse[]) as $p (
      {m: 1, n: 0};
      ( .n = .n + ($p | tonumber) * .m
      | .m *= 60
      )
    )
  | .n
  );

# 5100 -> "1h 25mins"
def to_fancy_duration:
  ( [(./(60*60) | floor), .%(60*60)] as [$h,$r]
  | $r
  | [(./60 | floor), .%60] as [$m,$r]
  | $r as $s
  | [ if $h > 0 then "\($h)h" else empty end
    , if $m > 0 then "\($m)mins" else empty end
    , if $s > 0 then "\($s)secs" else empty end
    ]
  | join(" ")
  );