Re: Ruby Quiz - Challenge #7 - Type Inference - Convert Strings to Null, Number, Not a Number (NaN), Date & More

Gerald Bauer wrote:
> Challenge #7 - Type Inference - Convert Strings to Null, Number, Not a
> Number (NaN), Date & More

$ ruby lib/007.rb
Run options: --seed 42919
# Running:
.
Finished in 0.015037s, 66.5023 runs/s, 665.0233 assertions/s.
1 runs, 10 assertions, 0 failures, 0 errors, 0 skips

$ cat lib/007.rb
require_relative '../007/test.rb'

gem 'parslet', '~> 1.8.2'
require 'parslet'

class RubyQuizTest
  @@parser = Class.new(Parslet::Parser) do
    rule(:dte) {
                 (
                   match('[0-9]').repeat(4)>>(
                     match('[.]')>>match('[0-9]').repeat(2)
                   ).repeat(2)
                 ).as(:dte)
               }
    rule(:flt) {
                 (
                   match('[0-9]').repeat>>match('\.')>>match('[0-9]').repeat
                 ).as(:flt)
               }
    rule(:int) {
                 match('[0-9]').repeat.as(:int)
               }
    rule(:nan) {
                 (
                   match('N')>>match('a')>>match('N')
                 ).as(:nan)
               }
    rule(:nul) {
                 (
                   match('N')>>match('i')>>match('l') |
                   match('N')>>match('u')>>match('l')>>match('l')
                 ).as(:nul)
               }
    rule(:str) {
                 match('.').repeat.as(:str)
               }
    rule(:foo) { nul | nan | dte | flt | int | str }
    root(:foo)
  end.new

  @@transf = Class.new(Parslet::Transform) do
    rule(:dte => simple(:dte)) { Date.strptime(dte, '%Y.%m.%d') }
    rule(:flt => simple(:flt)) { flt.to_f   }
    rule(:int => simple(:int)) { int.to_i   }
    rule(:nan => simple(:nan)) { Float::NAN }
    rule(:nul => simple(:nan)) { nil        }
    rule(:str => simple(:str)) { str.to_s   }
  end.new

  def convert(values)
    values.map{|v|
      @@transf.apply(@@parser.parse(v))
    }
  end
end

RubyQuizTest.new('fjc')



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