Tweak object displays in REPL

lib/chervil/ast/function.rb

 
       current_expr
     end
-
-    def to_s
-      "<function: #{@name.name}(#{@params.map(&:name).join(' ')})>"
-    end
   end
 end

lib/chervil/repl.rb

       @env = Env.new
     end
 
+    def display(obj)
+      case obj
+      when true
+        '#t'
+      when false
+        '#f'
+      when AST::Function
+        "<function: #{obj.name.name}(#{obj.params.map(&:name).join(' ')})>"
+      when Float
+        if obj.floor.to_f == obj
+          obj.to_i
+        else
+          obj
+        end
+      else
+        obj
+      end
+    end
+
     def run
       begin
         while line = Readline.readline("> ", true)
           end
 
           results = Interpreter.new(tree, @env).interpret
-          results.each { |result| puts result unless result.nil? }
+          results.each { |result| puts display(result) unless result.nil? }
         end
       rescue Interrupt
         puts