Metaprogramming EDN in ruby

gistfile1.rb

#Idiomatic record constructors in Ruby

#My C2PO grammar of graphics uses records (typed maps, basically) to represent pieces of the grammar.
#E.g., in Clojure you can specify a linear scale via a constructor function:
#
#    (scale/linear :domain [0 10] :label "The X Axis")
#
#returns the appropriate scale.linear record with the two key/value pairs given above.


#I'm trying to implement the same thing in Ruby; basically just shell records that only know how to serialize themselves out to EDN---no validation of arguments or anything.
#Here's the parent class:

module C2PO
  class C2PORecord < Hash
    def initialize(h={})
      self.merge! h
    end
    def to_edn
      _, prefix, name = self.class.name.split("::").map(&:downcase)
      EDN.tagout "com.keminglabs/c2po$#{prefix}$#{name}", {}.merge(self)
    end
  end
end


#then

module C2PO
  module Geom
    class Point < C2PORecord
    end
  end
end

#makes something I can instantiate as such:

include C2PO
p = Geom::Point.new :radius => 2
p.to_edn # => "com.keminglabs/c2po$geom$point {:radius 2}"

#however, the ::, capitalization, and #new feel a bit verbose.
#One alternative is to put constructors on the appropriate modules:

module C2PO
  module Geom
    class Point < C2PORecord
    end
    def self.point(h={})
      Point.new h
    end
  end
end

#and then call with the nicer syntax:

p = Geom.point :radius => 2

#but this requires the implementation to repeat itself (saying "point" three times).

#Ruby friends: is there a nice way I can metaprogram my way out of this?



#For reference, here's my solution in Clojure using actual macros (from: https://github.com/keminglabs/c2po-clojure/blob/master/src/clj/c2po/records.clj):

# (ns c2po.records
#   (:use [c2po.literals :only [print-literal]])
#   (:require [clojure.string :as str]
#             clojure.pprint))

# (defmacro def-c2po-record
#   [prefix name]
#   (let [record-name (str/capitalize (clojure.core/name name))]
#     `(do
#        (defrecord ~(symbol record-name) [])

#        ;;print the record appropriately with Clojure's regular and pretty print systems
#        (defmethod print-method ~(symbol record-name) [x# w#]
#          (print-literal ~prefix ~(clojure.core/name name) x# w#))
       
#        (defmethod clojure.pprint/simple-dispatch ~(symbol record-name) [x#] (pr x#))

#        ;;record constructor
#        (defn ~name [& kwargs#]
#          (~(symbol (str "map->" record-name))
#           (apply hash-map kwargs#))))))





# (ns c2po.geom
#   (:use [c2po.records :only [def-c2po-record]]))

# (def-c2po-record "geom" point)
# (def-c2po-record "geom" line)
# (def-c2po-record "geom" bar)
# (def-c2po-record "geom" boxplot)

Ping: @crnixon you have any thoughts on this?