java - Why does `ScalaObject` exist? -


why scala classes inherit scalaobject although trait empty , has no (visible?) functionality compared anyref, define additional methods?

won't slow down method calls equals() or hashcode() because need take class consideration (which might override methods)?

isn't possible fold anyref , scalaobject 1 class?

update: scalaobject was eradicated new 2.10 version of scala.

scalaobject inserts $tag method, which, according comment in library source code 2.7, "is needed optimizing pattern matching expressions match on constructors of case classes." since name starts $, should of course considered "hidden" application programmers. in scala 2.8, it's entirely empty, guess it's there backward compatibility.


Comments

Post a Comment

Popular posts from this blog

php - Vagrant up error - Uncaught Reflection Exception: Class DOMDocument does not exist -

i've set bento/ubuntu-16.04 vagrant box using php 5.6, , getting following error quite few times when try , run shell script: "uncaught reflection exception: class domdocument not exist". i've tried adding following top of script (not together), each no success: "sudo apt-get install php5.6-xml", "sudo apt-get install php5-xml", "sudo apt-get install php-dom" i've tried resetting server "sudo service apache2 restart". does have suggestions?
Read more

vue.js - Create hooks for automated testing -

Image
qa guys complained can't automate frontend testing. because our html looks same outside. lazy hack did this <template> <div :role="$options.name"> ... </div> </template> <script> export default { name: 'vmcomponentname' } </script> which takes name script , applies html. in browser get: <div role="vmcomponentname"> ... </div> line :role="$options.name" goes in every component. is there dry er solutions? please share. additional details i'll explain in details looking for. imagine have vmusercreate form creates user. test case can create user . to automatically test without role, have use following selector: .wrapper > .wrapper > .wrapper > .submit-button the test extremely brittle (will break lot). if use roles can use [role="vmusercreateform"] .submit-button selector. many folds less brittle. so basically, i'm ...
Read more

Add new key value to json node in java -

i have json file : { "id":1, "name":"abc", "addressdetails": { "city":"newyork" } } i wanted add 1 more key-value ("pincode" : "414141") node 'addressdetails'. i tried using : objectmapper mapper = new objectmapper(); jsonnode root = mapper.readtree(new file("d://test.json")); objectnode node = mapper.createobjectnode(); node.with("addressdetails").put("pincode", "414141"); but it's not getting added, there way can ? you can try you should modify file path objectmapper mapper = new objectmapper(); objectnode nodes = mapper.readvalue(new file("d:\\test.txt"), objectnode.class); nodes.with("addressdetails").put("pincode", "414141"); mapper.writer().writevalue(new file("d:\\test.txt"), nodes);
Read more