Class: Datasets::JapaneseDateParser

Inherits:
Object
  • Object
show all
Defined in:
lib/datasets/japanese-date-parser.rb

Defined Under Namespace

Classes: UnsupportedEraInitialRange

Constant Summary collapse

ERA_INITIALS = 
{
  "平成" => "H",
  "令和" => "R",
}.freeze

Instance Method Summary collapse

Instance Method Details

#parse(string) ⇒ Object 



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# File 'lib/datasets/japanese-date-parser.rb', line 10

def parse(string)
  case string
  when nil
    nil
  when /\A(平成|令和|..)\s*(\d{1,2}|元)年\s*(\d{1,2})月\s*(\d{1,2})日\z/
    match_data = Regexp.last_match
    era_initial = ERA_INITIALS[match_data[1]]
    if era_initial.nil?
      message = +"era must be one of ["
      message << ERA_INITIALS.keys.join(", ")
      message << "]: #{match_data[1]}"
      raise UnsupportedEraInitialRange, message
    end

    year = match_data[2]
    if year == "元"
      year = "01"
    else
      year = year.rjust(2, "0")
    end
    month = match_data[3].rjust(2, "0")
    day = match_data[4].rjust(2, "0")
    Date.jisx0301("#{era_initial}#{year}.#{month}.#{day}")
  else
    string
  end
end