(YEARLY) MINUTE MAP

The idea is you can specify a value (int by default) for any and every minute of an entire year. Which particular year isn't representable.

Time specifiers are like cron but hierarchical. Hierarchy and priority matching rules are used to determine the value for any given minute of the year. A specification takes the form of a set of <expression, value> pairs in JSON or as a dictionary.

An expression is a dot-separated sequence of time tokens. The wildcard "*" may appear as a standalone spec or as a leaf segment, and means "everything else" not matched my siblings at this level.

Input may be a flat nested form; nested dicts are flattened by joining their key paths with ".". Both dict and JSON string are accepted.

The method YearMinuteMap.get_value() takes a datetime, and returns a value by selecting the most specific matching spec's value . Example:

my_minute_map =  {
  "*": 8,
  "h5-10": 28,
  "h19": {
    "*": 18,
    "m30-59": 22
  },
  "q2": {
    "h0-4": 10,
    "h5-10": 30,
    "h11-18": 10,
    "h19-23": 20,
  },
  "q3": {
    "h0-4": 12,
    "h5-10": 32,
    "h11-18": 12,
    "h19-23": 20,
    "sun": {
      "h0-4": 14,
      "h5-10": 34,
      "h11-18": 14,
      "h19-23": 23,
    }
  }
}
spec = YearMinuteMap(my_minute_map)
spec.get_value(my_date) # -> value

Flat Example:

  {
    "*": 1,
    "q1": 2,
    "q1.sun.h1-10.m1": 3
    "q1.sun.h1-10.m2": 4
  }

Crontab like steps and lists are also supported:

{
    "h0-11.m*/2": 1,
    "h12-23.m*/3": 2
}

EBNF for expression:

SPEC      ::= "*" | PATH
PATH      ::=
  ( QTR | ( "." ( DOM_PATH | DOW_PATH | HH_PATH | MM ) )? )
  | ( MOY | ( "." ( DOM_PATH | DOW_PATH | HH_PATH | MM ) )? )
  | WOY ( "." ( DOW_PATH | HH_PATH | MM ) )?
  | DOY ( "." ( HH_PATH | MM ) )?
  | DOM_PATH
  | DOW_PATH
  | HH_PATH
  | MM
DOM_PATH  ::= DOM ( "." ( HH_PATH | MM ) )?
DOW_PATH  ::= DOW ( "." ( HH_PATH | MM ) )?
HH_PATH   ::= HH ( "." MM )?
QTR       ::= "q1" | "q2" | "q3" | "q4" // Quarter (maps to moy range internally)
MOY       ::= "moy" RANGE      // Month of year    1-12   (aliases: jan…dec)
WOY       ::= "woy" RANGE      // ISO week         1-53
DOY       ::= "doy" RANGE      // Day of year      1-366
DOM       ::= "dom" RANGE      // Day of month     1-31
DOW       ::= "dow" RANGE      // Day of week      1-7    (aliases: mon…sun, 1=Mon)
HH        ::= "h" RANGE        // Hour             0-23
MM        ::= "m" RANGE        // Minute           0-59
RANGE     ::= ( ( DIGITS | DIGITS "-" DIGITS ) | "*" ) ("/" DIGITS) | ( DIGITS (,DIGITS)+ )

The grammar does not allow use of the same type of token twice (ex "dom12.dom13") or certain chaining (ex "q1.apr").

MOY and DOW have aliases MONTH and WEEKDAY not shown in EBNF:

MONTH     ::= "jan" | "feb" | "mar" | "apr" | "may" | "jun" |
              "jul" | "aug" | "sep" | "oct" | "nov" | "dec"
WEEKDAY   ::= "mon" | "tue" | "wed" | "thu" | "fri" | "sat" | "sun"

Tie breaking: Longer (more dots) paths beat shorter ones. The following order is used for tie breaks where path length is the same:

    QTR < MOY < DOW < DOM < WOY < DOY < HH < MM

Then specificity of the RANGE expression is used.

TODO: allow user to specify ordering by inputing a OrderDict or array.