If the assumptions of a function call aren't satisfied, I find the "silent failure" of returning nil to be extremely problematic.
After all, you can't fix a problem if you don't know you have a problem (or where it is). As a result, I am definitely in the camp of the "fail-fast" philosophy. Liberal use of Prismatic Schema can help in this area by documenting & verifying the expected type of function arguments and its return value. Re the specific case of trying to lookup a non-existant key in a map, this is the precise reason I create the "grab" function in the Tupelo Core library <https://github.com/cloojure/tupelo#map-value-lookup>. This implements the "fail-fast" practice of notifying the caller as soon as a problem is detected, rather than silently ignoring the problem. Please take a look and tell me if you find it useful! Alan On Tue, Jan 12, 2016 at 12:25 PM, mattias w <matti...@gmail.com> wrote: > Clojure and Erlang are very similar, except for the syntax, macros and > that you can use Java libraries. > > There is one big difference: In Erlang, fail as early as possible is the > norm. In Clojure it is almost the opposite. > > Many errors in Clojure code will result in nil, and most operations accept > nil as a valid parameter, i.e. many fails will not even be visible unless > you check the result. > > The most common I stumble on is assuming that a value exists in a map, but > that is just the top of the iceberg > > I assume Rick H did this on purpose, and I am looking for pointers to > where the rationale behind is described. > > Thanks, > > Mattias > > > -- > 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.
