Here's even more concise version: (defmacro mo [op & args] (reduce (fn [& ab#] (cons op ab#)) args))
On Apr 23, 9:23 pm, "Dimiter \"malkia\" Stanev" <mal...@gmail.com> wrote: > You can make your own macro to do that: > > (defmacro mo [op & args] > (reduce (fn [a# b#] (cons op [a# b#])) args)) > > (mo + 1 2 3 4) > > (print "expanded=" (macroexpand '(mo + 1 2 3 4)) "\n") > > ;expanded= (+ (+ (+ 1 2) 3) 4) > > On Apr 23, 5:57 pm, Kevin Van Horn <kvanh...@ksvanhorn.com> wrote: > > > > > I'm writing an application that needs fast, high-quality random number > > generation, so I've been implementing a Mersenne Twister random number > > generator. I'm finding that bit-twiddling in Clojure can be a "bit" > > awkward. Here are some specifics: > > > 1. bit-and, bit-or, and bit-xor only take two arguments. These are > > all associative operations, and as such should take an arbitrary > > number of arguments for the same reason that + and * take arbitrary > > number of arguments: so you can write, e.g., > > > (op a1 a2 a3 a4) > > > instead of > > > (op (op (op a1 a2) a3) a4) > > > 2. There is no direct support for word-level, unsigned shifts. That > > is, I want to treat an int as the equivalent 32-bit unsigned value > > when I do the shift, shifting in 0 bits and dropping the bits that > > shift past the word boundaries. > > > It took a while to figure out how to do this correctly; the biggest > > problem was avoiding the propagation of the sign bit on a right > > shift. After experimenting around for a while I figured out that > > these will work: > > > * Left-shift x by n bits: (int (bit-shift-left x n)). > > > * Right-shift x by n bits: (int (bit-shift-right (bit-and intmask x) n)) > > where intmask = 2^32 - 1. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
