Re: Starting Clojure again

2017-09-06 12:44 GMT+02:00 Ray Miller : > By the way does has clojure something like super? Using: > >> (defn create-pin-hex >> ([] (create-pin-hex 8)) >> >> is asking for trouble. After copy/pasting from create-pin I almost forgot >> to change it. >> >> > If your base

Re: Starting Clojure again

On 6 September 2017 at 11:01, Cecil Westerhof wrote: > ​With the help of this list I rewrote it to: > (def digits > (apply str (map char (range (int \0) (inc (int \9)) > (def hex-digits > (apply str digits (map char (range (int \A) (inc (int \F)) > >

Re: Starting Clojure again

2017-09-06 9:58 GMT+02:00 Cecil Westerhof : > I want to start using Clojure again. I made the following simple function > to generate a PIN: > (defn create-pin > ([] (create-pin 8)) > ([n] >(let [chars (map char (range (int \0) (inc (int \9] > (reduce

Re: Starting Clojure again

2017-09-06 11:00 GMT+02:00 Ray Miller : > On 6 September 2017 at 09:50, Cecil Westerhof > wrote: > >> >> ​I am trying the following throwaway code: >> (defn create-pin >> ([] (create-pin 8)) >> ([n] >>{:pre [(<= n 128) >>(>= n 4)]} >>(let

Re: Starting Clojure again

On 6 September 2017 at 09:50, Cecil Westerhof wrote: > > ​I am trying the following throwaway code: > (defn create-pin > ([] (create-pin 8)) > ([n] >{:pre [(<= n 128) >(>= n 4)]} >(let [chars (into [] (concat (range (int \0) (inc (int \9))) (range > (int

Re: Starting Clojure again

2017-09-06 10:13 GMT+02:00 Cecil Westerhof : > Answering my own question. ;-) > > 2017-09-06 9:58 GMT+02:00 Cecil Westerhof : > >> The next step is that I want to use hexadecimal numbers. So I should use >> (range (int \0) (inc (int \9))) combined

Re: Starting Clojure again

2017-09-06 10:35 GMT+02:00 Mark Engelberg : > You could do that by calling vec on it. But you'd want to move the whole > let clause outside of the defn, so it is only evaluated once, not every > time the function is called. > ​Wen the function is finished. ;-) ​ >

Re: Starting Clojure again

2017-09-06 10:23 GMT+02:00 Colin Yates : > > The only way of answering that is with numbers, and I understand > https://github.com/hugoduncan/criterium/ is excellent for that. > > Personally, if I was asking that question I might also be wondering if > using a mutable data

Re: Starting Clojure again

You could do that by calling vec on it. But you'd want to move the whole let clause outside of the defn, so it is only evaluated once, not every time the function is called. But best, as I said earlier, is just to let chars be "0123456789ABCDEF". You can call nth on strings, so this is the most

Re: Starting Clojure again

The only way of answering that is with numbers, and I understand https://github.com/hugoduncan/criterium/ is excellent for that. Personally, if I was asking that question I might also be wondering if using a mutable data structure might be worth it (https://clojure.org/reference/transients). >

Re: Starting Clojure again

2017-09-06 10:13 GMT+02:00 dennis zhuang : > 1.Maybe you can use :pre metadata: > > (defn create-pin > ([] (create-pin 8)) > ([n] >{:pre [(<= n 16) > (>= n 4)]} >(let [chars (map char (range (int \0) (inc (int \9] > (reduce str (repeatedly n

Re: Starting Clojure again

(let [chars "0123456789ABCDEF"] ...) Replace `reduce` with `apply` to get the performance benefit of using a string builder behind the scenes. On Wed, Sep 6, 2017 at 12:58 AM, Cecil Westerhof wrote: > I want to start using Clojure again. I made the following simple

Re: Starting Clojure again

Answering my own question. ;-) 2017-09-06 9:58 GMT+02:00 Cecil Westerhof : > The next step is that I want to use hexadecimal numbers. So I should use > (range (int \0) (inc (int \9))) combined with (range (int \A) (inc (int > \F))). > How would I do that? > ​(concat

Re: Starting Clojure again

1.Maybe you can use :pre metadata: (defn create-pin ([] (create-pin 8)) ([n] {:pre [(<= n 16) (>= n 4)]} (let [chars (map char (range (int \0) (inc (int \9] (reduce str (repeatedly n #(rand-nth chars)) (create-pin 3) AssertionError Assert failed: (>= n 4)

Re: Starting Clojure again

Hi Cecil - welcome back! This would be perfect to test using the new clojure.spec. I can't give you any advice on the specifics as I have yet to break into it myself, but the properties of this function are crying out for generative testing. Cecil Westerhof writes: > I want to start using

Starting Clojure again

I want to start using Clojure again. I made the following simple function to generate a PIN: (defn create-pin ([] (create-pin 8)) ([n] (let [chars (map char (range (int \0) (inc (int \9] (reduce str (repeatedly n #(rand-nth chars)) So far so good. But I want to improve a