Polygons/Points/Arrays using Sequel for PostgreSQL

sequel_points.rb

require 'sequel'

class Point
  attr_accessor :long, :lat
  def initialize(long, lat)
    @long = long
    @lat = lat
  end

  def self.from_str(str)
    mstr = str.gsub /[()]/, ''
    long, lat = mstr.split(',').map(&:to_f)
    new long, lat
  end

  def to_s
    "(#{long},#{lat})"
  end

  def inspect
    "#<#{self.class.name}:#{to_s}>"
  end
  def sql_literal(*)
    "'#{to_s}'"
  end
end

class Polygon
  attr_accessor :points
  def initialize *points
    @points = points
  end

  def self.from_str(string)
    pairs = string.scan(/\(([0-9\-\.]+?),([0-9\-\.].+?)\)/).map {|s| s.map(&:to_f)}
    points = pairs.map {|pair| Point.new *pair}
    new *points
  end

  def sql_literal(*)
    lit = "'("
    lit << points.map(&:to_s).join(',')
    lit << ")'"
  end

end

# FIXME: set to your connection parameters
DB = Sequel.connect('postgres://jscott@localhost/test')

# Convert any pg point to Point class like Point.from_str(pg_string_value)
DB.conversion_procs[600] = Point.method(:from_str)
# Convert any pg polygon to Polygon class (with array of points)
DB.conversion_procs[604] = Polygon.method(:from_str)

# add the array handler
DB.extension :pg_array

# Because point[] is a non-standard type, we have to explicitly add it.
DB.register_array_type 'point'

geos = DB[:geos]

geo = geos.where(id: 1)

record = geo.first

def puts_detail(rec)
  rec.keys.each do |field|
    item = rec[field]
    puts "#{field}: \n\tClass: #{item.class} \n\tinspect: #{item.inspect} \n\tto_s: #{item} \n\n"
  end
end

puts_detail(record)

geos.filter(id: 2).delete
geos.insert(id: 2, center: Point.new(-97.7, 35.1), myshape: record[:myshape])
rec2 = geos.where(id: 2).first
puts "record 2"
puts_detail(rec2)

setup.sql

CREATE TABLE geos (
    id integer,
    myshape polygon,
    center point,
    point_arr point[],
    myarr integer[]
);

INSERT INTO geos 
VALUES(1, -- id integer
'((-113,47),(-85,47),(-113,35),(-85,35))', -- myshape polygon
'(-100,40)', -- center point
'{"(-113,47)","(-85,47)","(-113,35)","(-85,35)"}', -- point_arr point[]
'{1,2,3,4}' -- myarr integer[]
);