YouTube link: https://www.youtube.com/watch?v=uP-m8j8ZN-Q
Your hosts this episode: Daniel Spiewak, Heather Miller, Seth Tisue.
Daniel returns to the show, puts on his enterprise hat, and confesses his dark fetish!
Our guest is Martin Odersky, creator of Scala.
- Josh-less, Dick-less, music-less. our guest this week better be good
- London. 600 people, standing room only
- https://skillsmatter.com/conferences/1948-scala-exchange-2014
- Daniel remembers early on when it was 50 people in a basement
- intro talks, advanced talks pushing the limits of the type system. hopefully not too big a gap in between
- Martin: "the community as a whole is becoming more specialized". Scala plus this or that library
- Martin's keynote at Scala eXchange
- binary compatibility: it still pesters us
- why don't other languages suffer as much from this?
- Java is much closer to the JVM and much more conservative about making changes
- most other languages build from source
- should Scala build from source?
- but with what build tool?
- reproducible builds are hard to attain
- new idea: distribute Scala software as partially compiled "typed trees"
- "it's very simple to go from typed trees to bytecode" or some other back end like Scala.js
- typed trees compiled from Scala 2.n could be remapped for 2.(n + 1)
- typed trees are "in a sense a Scala-specific bytecode format... that capture Scala semantics better than Java bytecode"
- where/how will the trees be stored?
- other tools could take advantage of the trees, e.g. optimizers, analyzers, bug finders
- Daniel puts on his enterprise hat: what about code obfuscation? he's also concerned about performance whenever extra information is being carried around
- Seth: perhaps one day, distributing binaries alone will come to seem strange. it should be an optimization, not the default
- Heather: in web development we already have original JavaScript vs. compressed, stripped, optimized JavaScript
- everyone is a bit confused about attributes and annotations
- beware Heather, answer carefully!
- all agree: grading sucks
- Daniel rescues Heather by recalling a class assignment to write a Scala compiler in C (?!)
- and confesses his "dark fetish" for C
- https://en.wikipedia.org/wiki/Cool_(programming_language)
- will Scala support .NET again?
- (viewer question from Pablo Perez)
- Martin: "It depends on the community."
- for the old Scala.NET effort, "there was no community... in the end it became sterile"
- Martin: "I'm in awe" of the Scala.js community, what they've achieved and how much fun they're having
- http://www.scala-js.org
- "they even have a really nice book" (by Haoyi Li)
- Daniel: the hard part is semantic mismatches between the JVM and other targets
- Martin: one language addition is needed for Scala.js: different handling of pattern matching for numeric types, to reduce boxing
- Seth: why hasn't FP gotten that much traction yet for client work, for UIs?
- Martin agrees it's a historical accident
- functional reactive programming ftw
- Heather: popular JavaScript libraries increasingly reflect functional ideas, e.g. React from Facebook
- Daniel: on iOS, Cocoa "increasingly approaches FRP"
- Martin: can we sell types to the front-end people?
- Daniel likes the record polymorphism in JavaScript (and OCaml)
- not only doesn't JavaScript have types, it doesn't have a culture of testing, either?
- will changes from Typelevel Scala be merged into main Scala?
- (viewer question from Dan Osipov)
- http://typelevel.org
- Typelevel's policy is not to break backwards compatibility, so why not?
- "we are working together very well" -- Typelevel can prototype things fast, standard Scala changes take years
- Daniel: Typelevel is discovering how hard it is to change anything without breaking compatibility
- example: Erik Osheim's work on byte literals
- example: type lambdas
- "everything has been hidden behind flags"
- Martin: the Scala community build (1.4 million lines of community code) can help decide whether a corner case is an issue in practice
- popular features in Typelevel Scala could become natural candidates for inclusion in standard Scala
- will there be more Scala courses on Coursera?
- (viewer question from Jatin Puri)
- previous courses: https://www.coursera.org/course/progfun, https://www.coursera.org/course/reactive
- potential third course on "parallel programming, parallel transformations". including the distributed computing, Spark. "very early stages, we're not sure yet" when or if
- data parallelism as opposed to reactive
- Heather: what should the Scala community be doing, what are we not doing, where is the community and where is it heading?
- Martin: it's bigger, there's been some drama, ...
- direction: "transparent, open collaboration" on "fast-moving open-source things"
- meanwhile, Typesafe is the "backstop" for the enterprise
- comparison with Spark community
- Typesafe's efforts to modularize the standard library to facilitate contributions
- Martin: hey Daniel, how about that Anti-XML thing?
- Tell us about lightweight modular staging. Will the Scala.meta project give us staged compilation?
- (viewer questions from Rúnar Bjarnason and Gabriel Campero [sp?])
- Compilation at runtime, for efficiency
- Lightweight modular staging uses the type system heavily
- Issues: fragile implicits, slow compile times. Ongoing efforts to improve
- Scala.meta attempts to make these techniques "more digestible". In flux, no clear winner.
- thanks Martin!
