Add some methods and remove some methods

spec/monads/just_spec.cr

@@ -13,29 +13,17 @@ describe Monads::Just do
     end
   end
 
-  describe "#equal?" do
-    it "equal for same values" do
-      boolean = Monads::Just.new(1).equal?(Monads::Just.new(1))
-      boolean.should be_truthy
-    end
-
-    it "not equal for differents values" do
-      boolean = Monads::Just.new(1).equal?(Monads::Just.new(2))
-      boolean.should be_falsey
-    end
-  end
-
-  describe "#success?" do
-    it "is success" do
+  describe "#just?" do
+    it "verify that type is Just" do
       boolean = Monads::Just.new(1)
-      boolean.success?.should be_truthy
+      boolean.just?.should be_truthy
     end
   end
 
-  describe "#failure?" do
-    it "is not failure" do
+  describe "#nothing?" do
+    it "verify that type is not Just" do
       boolean = Monads::Just.new(1)
-      boolean.failure?.should be_falsey
+      boolean.nothing?.should be_falsey
     end
   end
 
@@ -97,4 +85,11 @@ describe Monads::Just do
       expectation.should eq(1)
     end
   end
+
+  describe "#to_s" do
+    it "validate string" do
+      monad = Monads::Just.new(nil)
+      monad.to_s.should eq("#{typeof(monad)}{#{monad.value!.inspect}}")
+    end
+  end
 end

spec/monads/nothing_spec.cr

@@ -18,29 +18,17 @@ describe Monads::Nothing do
     end
   end
 
-  describe "#equal?" do
-    it "equal for same values" do
-      boolean = Monads::Nothing(String).new.equal?(Monads::Nothing(String).new)
-      boolean.should be_truthy
-    end
-
-    it "not equal for differents values" do
-      boolean = Monads::Nothing(Int32).new.equal?(Monads::Just.new(2))
-      boolean.should be_falsey
-    end
-  end
-
-  describe "#success?" do
-    it "is success" do
+  describe "#just?" do
+    it "verify that type is not Just" do
       boolean = Monads::Nothing(Nil).new
-      boolean.success?.should be_falsey
+      boolean.just?.should be_falsey
     end
   end
 
-  describe "#failure?" do
-    it "is not failure" do
+  describe "#nothing?" do
+    it "verify that type is Just" do
       boolean = Monads::Nothing(Nil).new
-      boolean.failure?.should be_truthy
+      boolean.nothing?.should be_truthy
     end
   end
 
@@ -103,4 +91,11 @@ describe Monads::Nothing do
       # expectation.should eq(0)
     end
   end
+
+  describe "#to_s" do
+    it "validate string" do
+      monad = Monads::Nothing(Nil).new
+      monad.to_s.should eq("#{typeof(monad)}")
+    end
+  end
 end

src/monads/maybe.cr

@@ -1,13 +1,13 @@
 module Monads
   abstract class Maybe(T)
-    def ==(rhs : RightBiased | LeftBiased) : Bool
-      equal?(rhs)
+    def just?
+      typeof(self) == Just(T)
     end
 
-    abstract def success?
-    abstract def failure?
+    def nothing?
+      !just?
+    end
 
-    abstract def equal?(rhs : RightBiased | LeftBiased)
     abstract def value!
     abstract def value_or(element : U) forall U
     abstract def value_or(&block : -> U) forall U
@@ -29,12 +29,16 @@ module Monads
       Just(U).new(block.call(@data))
     end
 
-    def equal?(rhs : Just(U)) : Bool forall U
-      @data == rhs.value!
+    def to_s
+      "#{typeof(self)}{#{value!.inspect}}"
     end
 
-    def equal?(rhs : Nothing(U)) : Bool forall U
-      false
+    def inspect(io)
+      io << to_s
+    end
+
+    def ==(other : self) : Bool
+      other.value! == value!
     end
   end
 
@@ -52,5 +56,17 @@ module Monads
     def equal?(rhs : Nothing(U)) : Bool forall U
       typeof(self) == typeof(rhs)
     end
+
+    def to_s
+      "#{typeof(self)}"
+    end
+
+    def inspect(io)
+      io << to_s
+    end
+
+    def ==(other : self) : Bool
+      typeof(self) == typeof(other)
+    end
   end
 end