I can do (#((get {1 {:foo 2}} %) :foo) 1). But (map #((get {1 {:foo 2}} %) :foo) (1)) gives a ClassCastException. How would I use map, a function like that and a list together?

what is your expected output?

You need to add ' before the (1)

(map #((get {1 {:foo 2}} %) :foo) '(1))

or (map #((get {1 {:foo 2}} %) :foo) (list 1))

I was hoping to get a (2). Using '(1) works in that example but what should I use if the (1) was passed along in a ->> chain?

I'll see if I can write my code some other way.

I'm trying to take a list of random kanji and sort them into the different grades as seen here: https://de.wikipedia.org/wiki/J%C5%8Dy%C5%8D-Kanji where I'm stuck is how to go over multiple lists to see which one it's a part of, would appreciate any help!

Checking to see if I understand what you are trying to do: You have some input strings, containing perhaps Unicode character sequences, as Java and Clojure on Java support out of the box, and you want to determine for each of those characters, which of several sets it is in?

If that is correct, one way to do this would be to create a Clojure map, where each key is a single character, and the associated value for a character C is the identifier of the set it lies within, e.g. perhaps a number identifying the set, or a string that is the name of that set of characters. If you create a Clojure map named m, you can then look up any object x in it, and get the associated value, via one of several possible expressions. One is simply (m x).

If that is on the right track at all, then you might have questions about good ways to create such a Clojure map.

that's right! I was thinking about more of a brute-force attempt, making maps/sets for each grade and go through them, since making one big map with the corresponding map seems like more initial effort

More initial effort in terms of the amount of code to write? Or more compute time for the computer?

If you will be categorizing thousands of characters, for example, then the compute time to create the map is probably not going to be terribly significant.

more like it seems harder to me to create a map with all the values than creating a map for each grade with just the characters in it

Let me show a sample of a bit of Clojure code, using characters from the English alphabet to make the example easier for me 🙂

Suppose we want all of the characters in the string "abc" to be set number 1, and all characters in "def" to be set number 2

Here is a way to turn the first string into a sequence of pairs, where each pair is one character followed by the number 1:

user=> (for [ch "abc"] [ch 1])
([\a 1] [\b 1] [\c 1])

That is not a map, but it is easy to turn such a sequence of pairs into a map with into, like this:

user=> (into {} (for [ch "abc"] [ch 1]))
{\a 1, \b 1, \c 1}

If you have two maps, you can combine them together with merge, like this:

user=> (merge (into {} (for [ch "abc"] [ch 1])) (into {} (for [ch "def"] [ch 2])))
{\a 1, \b 1, \c 1, \d 2, \e 2, \f 2}

Feel free to try that out in a REPL, with variations of your own, or ask questions if any of those don't make sense.

If you get comfortable with that, you can try these out, too:

user=> (def char->setid (merge (into {} (for [ch "abc"] [ch 1])) (into {} (for [ch "def"] [ch 2]))))
#'user/char->setid
user=> (map char->setid "deadcafe")
(2 2 1 2 1 1 2 2)

that does seem more manageable 🙂 need to wrap my head around char->setid later, will definitely play around with it in a repl! thanks for the help so far

char->setid is just a name of a symbol here. It works just as well if you call it m instead.

some people like to throw a few unusual characters into their names of things, and foo->bar is sometimes used by people as a name of a function, or a map, which takes a 'foo' kind of thing, and gives you back a 'bar'. You can leave out the weird characters if they throw you off.

Hey, I just noticed this behaviour

user=> (clojure.string/split ",2" #",")
["" "2"]
user=> (clojure.string/split "1," #",")
["1"]

Because that’s the way it is in Java

user=> (clojure.string/split ",2" #"," -1)
["" "2"]
user=> (clojure.string/split "1," #"," -1)
["1" ""]

This works: (map #(get {2 "asdf"} (% :bar)) '({:bar 2})) and I get a ("asdf") from it. I'd like to get something like ({:x "asdf"}). I'm trying to do something like (map #({:x (get {2 "asdf"} (% :bar))}) '({:bar 2})) but I get an error about having a wrong number of args. Could someone please point out my error?

Well, now. (map (fn [x] {:x (get {2 "asdf"} (x :bar))}) '({:bar 2})) works.

What is this thing #ig/ref inside duct applications? I want to learn how this is defined and reasons behind it.

I mean general ideas.

@ahmed1hsn https://github.com/weavejester/integrant#usage

is there some core function that is similar to when, but when the arg is true, returns the arg, else will return a default value?

something like (??? nil :default) ;;=> :default and (??? :whatever :default) ;;=> :whatever

or

oh xD of course

thanks

Which codebase would you recommend to read for it clarity and idiomatic way? J

Just for curiosity. I mean it would be anything you like it to read from time to time

For discovering new functions or way of doing

https://funcool.github.io/clojurescript-unraveled/ Hey, can I ask more experienced programmers here, what do you think of this book, ClojureScript unraveled? I am currently at the beginning of 3.9 section, and it seems to me that so far the explanations are pretty clear, with good examples (so far). P.S. If you know more appropriate channel where I should ask this question - feel free to suggest it, so I know for the next time.