use understore instead of downcase

Gemfile

@@ -1,5 +1,8 @@
 source 'https://rubygems.org'
 
+gem "i18n", "0.7.0"
+gem "activesupport-inflector", "0.1.0"
+
 group :development, :test do
   gem 'pry', '0.10.1'
   gem 'funkify', '0.0.4'

Gemfile.lock

@@ -1,9 +1,11 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    activesupport-inflector (0.1.0)
     coderay (1.1.0)
     diff-lcs (1.2.5)
     funkify (0.0.4)
+    i18n (0.7.0)
     method_source (0.8.2)
     pry (0.10.1)
       coderay (~> 1.1.0)
@@ -28,7 +30,9 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  activesupport-inflector (= 0.1.0)
   funkify (= 0.0.4)
+  i18n (= 0.7.0)
   pry (= 0.10.1)
   rspec (= 3.4.0)
 

lib/monadt/adt.rb

@@ -1,4 +1,4 @@
-require 'pry'
+require 'active_support/inflector'
 
 AdtPattern = Struct.new :klass, :lambda
 
@@ -13,10 +13,10 @@ def data(*fields)
 
 def decorate_adt(klass)
   klass.constants.each do |v|
-    name = v.to_s.downcase
+    name = v.to_s.underscore
     const = klass.const_get v
     klass.constants.each do |is_v|
-      is_name = is_v.to_s.downcase
+      is_name = is_v.to_s.underscore
       ret = is_v == v
       const.class_eval do
         define_method "is_#{is_name}?" do ret end

spec/monadt/adt_spec.rb

@@ -3,7 +3,7 @@
 class TestAdt
   One = data :foo, :bar
   Two = data :foo
-  Three = data
+  AndThree = data
 end
 
 decorate_adt TestAdt
@@ -14,22 +14,22 @@ class UseAdts
   def adt_func(o)
     match o,
       with(TestAdt::One, ->(foo, bar) { foo.to_s + bar.to_s }),
-      with(TestAdt::Three, ->() { 10 }),
+      with(TestAdt::AndThree, ->() { 10 }),
       with(Default, ->() { "default" })
   end
 
   def adt_func2(o)
     match o,
       with(TestAdt::One) { |foo, bar| foo.to_s + bar.to_s },
-      with(TestAdt::Three) { 10 },
+      with(TestAdt::AndThree) { 10 },
       with(Default) { "default" }
   end
 end
 
 describe 'Algebraic Data Types' do
   let(:v1) { TestAdt.one 1, :five }
   let(:v2) { TestAdt.two "hoi" }
-  let(:v3) { TestAdt.three }
+  let(:v3) { TestAdt.and_three }
   let(:subject) { UseAdts.new }
 
   describe 'proc/block based ADTs' do
@@ -51,18 +51,18 @@ def adt_func2(o)
     it 'supports blocks' do
       expect(v1.is_one?).to be true
       expect(v1.is_two?).to be false
-      expect(v1.is_three?).to be false
+      expect(v1.is_and_three?).to be false
       expect(v1.to_s).to eq("One(1, five)")
 
       expect(v2.is_one?).to be false
       expect(v2.is_two?).to be true
-      expect(v2.is_three?).to be false
+      expect(v2.is_and_three?).to be false
       expect(v2.to_s).to eq("Two(hoi)")
 
       expect(v3.is_one?).to be false
       expect(v3.is_two?).to be false
-      expect(v3.is_three?).to be true
-      expect(v3.to_s).to eq("Three")
+      expect(v3.is_and_three?).to be true
+      expect(v3.to_s).to eq("AndThree")
     end
   end
 end