Remove output.write

Many plugins only define a puts method on the output object. This change
removse the ability to customize the formatter used when outputting
variables in `ls`. We should reconsider the best way to do this.

lib/pry.rb

@@ -46,6 +46,7 @@ class Pry
     colorized = colorized.sub(/(\n*)\z/, "\e[0m\\1") if Pry.color
 
     result = colorized.gsub(/%<(.*?)#{nonce}/, '#<\1')
+    result = "=> #{result}"if options[:hashrocket]
     Helpers::BaseHelpers.stagger_output(result, output)
   end
 

lib/pry/commands/ls.rb

@@ -318,7 +318,7 @@ class Pry
 
     def format_value(value)
       accumulator = StringIO.new
-      Pry.print.call(accumulator, value)
+      Pry.output_with_default_format(accumulator, value, :hashrocket => false)
       accumulator.string
     end
 

lib/pry/pry_instance.rb

@@ -336,7 +336,6 @@ class Pry
     if last_result_is_exception?
       exception_handler.call(output, result, self)
     elsif should_print?
-      output.write(Pry.config.output_prefix)
       print.call(output, result)
     else
       # nothin'

spec/pry_defaults_spec.rb

@@ -92,7 +92,7 @@ describe "test Pry defaults" do
   end
 
   it "should set the print default, and the default should be overridable" do
-    new_print = proc { |out, value| out.puts "LOL" }
+    new_print = proc { |out, value| out.puts "=> LOL" }
     Pry.print =  new_print
 
     Pry.new.print.should == Pry.print
@@ -102,7 +102,7 @@ describe "test Pry defaults" do
     @str_output = StringIO.new
     Pry.new(:input => InputTester.new("\"test\""), :output => @str_output,
             :print => proc { |out, value| out.puts value.reverse }).rep
-    @str_output.string.should == "=> tset\n"
+    @str_output.string.should == "tset\n"
 
     Pry.new.print.should == Pry.print
     @str_output = StringIO.new

spec/pry_output_spec.rb

@@ -34,10 +34,10 @@ describe Pry do
       mock_pry("[1]").should =~ /^=> \[1\]/
     end
 
-    it "should not include the =>" do
+    it "should include the =>" do
       accumulator = StringIO.new
       Pry.config.print.call(accumulator, [1])
-      accumulator.string.should == "\[1\]\n"
+      accumulator.string.should == "=> \[1\]\n"
     end
 
     it "should not be phased by un-inspectable things" do
@@ -57,7 +57,7 @@ describe Pry do
     it "should colorize strings as though they were ruby" do
       accumulator = StringIO.new
       Pry.config.print.call(accumulator, [1])
-      accumulator.string.should == "[\e[1;34m1\e[0m]\e[0m\n"
+      accumulator.string.should == "=> [\e[1;34m1\e[0m]\e[0m\n"
     end
 
     it "should not colorize strings that already include color" do
@@ -68,7 +68,7 @@ describe Pry do
       accumulator = StringIO.new
       Pry.config.print.call(accumulator, f)
       # We add an extra \e[0m to prevent color leak
-      accumulator.string.should == "\e[1;31mFoo\e[0m\e[0m\n"
+      accumulator.string.should == "=> \e[1;31mFoo\e[0m\e[0m\n"
     end
   end