Thanks, everyone, your responses are very helpful and much appreciated. On Thu 10/27/16 09:57AM, lvh wrote:
> comp takes a number of functions and returns a function. Threading macros take a > number of forms (expressions) and return an expression. The threading macro does > not need a partial, because it operates on the form and injects something in it > (in the second position for ->, last position for ->>). The comp version does > need a partial, because `(interpose \-)` is not a function — it is just a form. On Thu 10/27/16 03:00PM, Gary Trakhman wrote: > Comp does its work at run-time, so you have to call functions that return > functions. Threading macros do their work at compile-time, so your form > literally compiles to this: These points are helpful for me to keep in mind: * `comp` works with functions, and `->>` works with forms. * `comp` is runtime, while `->>` is compile-time. The arguments to `comp` will be evaluated at runtime and should be callable functions. Looking at the macro expansion of `->>` is very helpful and straightforward to understand. The `->>` macro will setup an expression at compile-time that will be evaluated all at once during runtime. For `comp`, at runtime, `(map str/lower-case)` and `(interpose \-)` will return transducers, and `partial` is needed to create the intended function, e.g., `str/lower-case` bound to `map` and expecting a collection argument. -- 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.
