News for hackers. Stuff that matters.

A comment on Introducing Swift. Parent comment

Re:Introducing Swift by DanielRibeiro on Monday June 02, 2014 @04:07PM (#7835948)
Swift's environment is also very similar to Elm's time travel debugger: http://debug.elm-lang.org/

Direct link to Elm's demo similar to Bret Victor's: http://debug.elm-lang.org/edit/Mario.elm (video: https://www.youtube.com/watch?v=RUeLd7T7Xi4)

[ Parent | on HN ]
Re:Introducing Swift by AlexanderDhoore on Monday June 02, 2014 @04:43PM (#7836241)
I immediately thought about that as well. I wonder how they pull it off? Swift is not a functional language, so they just save every single variable, or what?
[ Parent | on HN ]
Re:Introducing Swift by seanmcdirmid on Monday June 02, 2014 @04:54PM (#7836310)
Time travel debugging has existed for a long time, and it's not limited to functional languages; the most obvious way they could do this is through checkpointing.
[ Parent | on HN ]
Re:Introducing Swift by cwp on Monday June 02, 2014 @05:36PM (#7836610)
Checkpointing is a natural fit with the Cocoa API, which uses an event loop. Just save the state of the application after each event is handled.
[ Parent | on HN ]
Re:Introducing Swift by gtrak on Wednesday June 04, 2014 @01:41PM (#7846992)
Just a hunch, LLVM uses Static-Single-Assignment, which is just that, saving every single variable change.
[ Parent | on HN ]