R/env_vars.R

In JosiahParry/placekey: An R Library for Placekeys

# Environment variables
# these are copied from the python library
RESOLUTION = 10
BASE_RESOLUTION = 12
ALPHABET = tolower('23456789BCDFGHJKMNPQRSTVWXYZ')
ALPHABET_LENGTH = nchar(ALPHABET)
CODE_LENGTH = 9
TUPLE_LENGTH = 3
PADDING_CHAR = 'a'
REPLACEMENT_CHARS = "eu"
REPLACEMENT_MAP = c(
  "prn" = "pre",
  "f4nny" = "f4nne",
  "tw4t" = "tw4e",
  "ngr" = "ngu",  # 'u' avoids introducing 'gey'
  "dck" = "dce",
  "vjn" = "vju",  # 'u' avoids introducing 'jew'
  "fck" = "fce",
  "pns" = "pne",
  "sht" = "she",
  "kkk" = "kke",
  "fgt" = "fgu", # 'u' avoids introducing 'gey'
  "dyk" = "dye",
  "bch" = "bce"
)


# extracted the regex from the python library
WHERE_REGEX <- '^[23456789bcdfghjkmnpqrstvwxyzeua]{3}-[23456789bcdfghjkmnpqrstvwxyzeu]{3}-[23456789bcdfghjkmnpqrstvwxyzeu]{3}$'
WHAT_REGEX <- '^[23456789bcdfghjkmnpqrstvwxyz]{3}(-[23456789bcdfghjkmnpqrstvwxyz]{3})?$'

BASE_CELL_SHIFT = 2 ^ (3 * 15)    # Adding this will increment the base cell value by 1
UNUSED_RESOLUTION_FILLER = 2 ^ (3 * (15 - BASE_RESOLUTION)) - 1
FIRST_TUPLE_REGEX = paste0('[', ALPHABET, REPLACEMENT_CHARS, PADDING_CHAR , ']{3}')
TUPLE_REGEX = paste0('[', ALPHABET, REPLACEMENT_CHARS, ']{3}')

# Taking the calculated value from python.
HEADER_INT <- 621496748577128448