Hi Wes, I'd be on the "don't do that" side of the fence. I did something similar when I first moved from Java to a dynamically typed language (I suspect that most people do) and it hinders at least as much as it helps.
For me, the thing that I needed to internalise is that Clojure isn't lacking types, dynamic typing isn't a deficiency. Both static and dynamic typing are features with pros and cons. Clojure has chosen to take advantage of the features of dynamic typing. Trying to superimpose a pseudo-static type system on top of it leaves you in a worst case scenario - none of the benefits of dynamicity and no real type-safety. Turning on *warn-on-reflection* and using type-hints, where appropriate, isn't unreasonable and might help to give you some comfort whilst your instincts attune themselves. R. On 23 Jul 2014, at 03:59, Wesley Hall <wesley.h...@gmail.com> wrote: > Hello folks, > > My question is, "Is it 'idiomatic' to perform type checking of function > arguments in :pre conditions"? > > Coming to clojure from 15 or so years of Java development has been something > of a revelation to me, but I am worried that I am still struggling a bit with > some old habits, one of which is to type check my function arguments. I > cannot get over this feeling of, "OMG!! What if somebody passes a string to > this function that requires a function argument!! The world will surely > end!". > > I am finding myself developing a bit of a habit of introducing type checks in > :pre conditions, but I am not sure whether the more 'clojure' thing to do is > to allow the exception to occur further down the call stack when the > reference is actually used in an inappropriate way (I attempt to call the > string as if it were a function). > > I have found a few cases where the error 'invites me' to implement a protocol > to 'teach' the system how to handle the particular type, which tends to > suggest to me that it might be better not to type check in a pre condition, > since at some later point I could decide to make the argument type valid by > defining a protocol implementation to handle the type successfully. > > I am also aware of the existence of core.typed, which is perhaps something I > should look into in more detail. > > Do people have thoughts on this? How do you handle this in your production > clojure code? > > Thanks > > Wes > > -- > 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 > Note that posts from new members are moderated - please be patient with your > first post. > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- 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 Note that posts from new members are moderated - please be patient with your first post. 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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
