This is a nice post . . . would the partially static typing come from the IDE? That seems like the trend right now, but then you gotta get a good IDE, and no two would ever be the same, which I think is controversial.
On Wed, Mar 11, 2009 at 4:27 PM, chris <cnuern...@gmail.com> wrote: > > I don't think it is impossible to begin adding type inference and > stronger typing to clojure or any fully dynamic language. > > You could begin with a set of runtime tests (such as range of a given > number or what keys are in a dictionary). These tests allow you to go > from an untyped world to a typed world, essentially saying if it > passes test X then it fullfills the contract for type Y. > > Next you can run all the type inference you want within sections of > your code. Where types can be inferred they are and where they can't > be runtime tests are used to ensure they match what one would expect. > > In short, I think that it is theoretically possible to add partial > static typing (Hindley-Milner if you desire) to any fully dynamic > language. I also think that it is possible, using this system of an > extensible type system, to allow eiffel style contracts to be > partially checked at compile time and partially checked at runtime > thus getting you the benefits of contract based programming without > typing your fingers to the bone writing asserts and programming in > tedious, error prone ways that a machine should be able to generate. > > There is significant overhead to learning to use any sort of type > inference as the errors you get are quite mystifying at first. > > In any case, people have built very large, long lived, performant, and > stable systems with dynamic languages. They have built these systems > just as quickly as people building systems with statically (and > strongly) typed languages and in a lot of cases quicker. I don't > think anyone has ever proved that a type system drastically increases > productivity for experienced programmers, regardless of the types of > bugs it finds. So it seems ridiculous to me, in a practical sense, to > force a given type system for every line of code in a program. > > I think that it is also damn useful to have the compiler catch a lot > of problems. I personally love working in F# and think C# is a joke > in terms of amount of code you have to write to get something done. > > I don't think that very much of what Jon said was irrelevant or FUD, > and I don't think that even though emotions are high on this subject > that the proponents of fully dynamic typing are spewing a bunch of > nonsense either. > > Lets take this discussion forward and think of how we could > incrementally add the important benefits of strongly typed and > inferred systems like ML, Haskell, and F# to Clojure while keeping the > very beautiful and clean syntax and minimal mental overhead of using a > LISP derivative. > > Chris > > On Mar 11, 2:12 pm, Jon Harrop <j...@ffconsultancy.com> wrote: > > On Wednesday 11 March 2009 18:35:46 Cosmin Stejerean wrote: > > > > > On Wed, Mar 11, 2009 at 1:03 PM, Jon Harrop <j...@ffconsultancy.com> > wrote: > > > > Another red herring: you are describing a disadvantage of nominal > over > > > > structural typing. Not dynamic vs static typing. > > > > > You are correct, my apologies. I was trying to show an example of > > > situations where what I know and what the compiler wants is different, > but > > > as you pointed out my example is only valid in the case of a nominal > type > > > system. > > > > No problem. > > > > The most commonly cited examples in academia are the fix point combinator > and > > polymorphically recursive functions, neither of which type directly in > the > > Hindley-Milner type system that today's statically-typed FPLs are almost > all > > based upon. However, not only do both OCaml and Haskell handle those > examples > > fine but the examples themselves are of little practical relevance. > > > > -- > > Dr Jon Harrop, Flying Frog Consultancy Ltd. > http://www.ffconsultancy.com/?e > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
