jbr/sibilant

Javascript with a lisp

francesco agati

@francescoagati

hello

i have try to implement an infix macro with pipe operator. but i have a problem the macro aren't expanded

this is the example code

(macro infix (...pairs)
(var first (pairs.splice 0 1))
(var x (|> pairs destructure))
(var exprs (x.map (#(pair)
(var pair_0 (get pair 0) pair_1 (get pair 1))
(@pair_0 @pair_1) ))) (console.log first) (var list (|> [first] (.concat exprs)))(pipe ...@list))

(alias-macro infix $i)

and an example of my macro

(macro suma (a b) `(+ @a @b))
(suma 1 2)
($i "a" suma "b" suma "c")
($i "a" + "b" + "c")

aeolus8

@aeolus8

Hello I am trying to take in an array of strings and count how many times a string in the array appears in the array (confusing) for example if there is string[] { "hello", "hi", "hi", "hello", "hi"} I would like to be able to print out hello 2, hi 3

@sleepyfox

Try this @aeolus8

(var strings (list 'hello 'hi 'hi 'hello 'hi)) 
(def count-items (acc, x) (if (get acc x) (do (set acc x (+ 1 (get acc x))) acc) (do (set acc x 1) acc)))
(.reduce strings count-items (hash))

aeolus8

@aeolus8

@sleepyfox Wow I don't think I would have figured out something this clean. thank you I appreciate it! Do you know if there is a sort method for a hash? I think I want to present the highest occurring string first.

@sleepyfox

Object properties have no intrinsic ordering, so first you need to convert the object to an array of tuples, one for each entry. Then sort that array using a custom function that compares the second element of the tuples. Simples!

P.S. Don't worry that this isn't obvious, there's a kind of mental gymnastics at work in solving programming problems, you get better with practice.

Michael Klarman

@mklarman

Hello all. I have a few questions on sibiliant. Can anyone help me?

Fred Daoud

@foxdonut

@mklarman what are your questions?

Michael Klarman

@mklarman

how do you push an item to an array?

what is the syntax for it?

Fred Daoud

@foxdonut

(append ["a" "b"] "c")

Michael Klarman

@mklarman

cool

Fred Daoud

@foxdonut

result: [ 'a', 'b', 'c' ]

Michael Klarman

@mklarman

How about for a loop in a loop?

Fred Daoud

@foxdonut

Depends, what are you trying to achieve?

Michael Klarman

@mklarman

i want to iterate through an array and push to a new array all items just one time getting rid of all doubles, then I want to loop New Array and loop orig array and count the number of times the item appears and save that number

how do you start a new project once you've downloaded sibilant?

Fred Daoud

@foxdonut

The first question is probably a good one for @sleepyfox :wink:

Fred Daoud

@foxdonut

For the second question, it depends on your build tools...

here are two examples

hello-sibilant just compiles one file

sibilant-mithril-seview compiles all the files and bundles them with browserify

@sleepyfox

@mklarman depends, are you deploying to Nodejs or the browser?

"getting rid of all doubles" sounds like a set. Counting occurrences sounds very much like the previous answer I gave on Mar 29 with the count-items function. Can you give us an example to make it clearer what you're trying to do?

Michael Klarman

@mklarman

is anyone here?

Fred Daoud

@foxdonut

hello

Michael Klarman

@mklarman

I have been asked to do a small project in sibilant. How can I test my code other than in the sibilant console? Will it work on a webpage like js? How can I start a project in sibilant? What are the file extensions?

aeolus8

@aeolus8

@sleepyfox Thank you for all the advice and info. I'm coming from a back-end c# experience and I dont work with this or even JS. Very confusing syntax in my opinion

@sleepyfox

@aeolus8 I'm guessing you've never done any LISP before? Because basically there is no syntax apart from S-expressions...

@CharlesSPatterson AFAIK append still works. Alternatively you can use something like:

(var my-list (list 1 2 3))
(my-list.push 4)

Remember that lists are just JS Arrays, so all of your normal Array methods work.

@sleepyfox

@mklarman you might want to check out https://github.com/sleepyfox/sibilant-starter

@sleepyfox

^^I've just pushed a change that updates out-of-date old dependencies.

Fred Daoud

@foxdonut

@mklarman if you scroll up you will see that I gave you two examples.

Karthik Rumalla

@ronaldo1769

@sleepyfox Can you please tell me how to code custom sorting to sort hashmap based on values? Thank you.

Michael Klarman

@mklarman

if I have an array [1 7 100 3] and I do the .sort function on it, it returns [1 100 3 7]. Why?

@sleepyfox

@mklarman Because JS has the default sort for arrays being alphabetical - see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort - this catches out most people who are new to JS.

@sleepyfox

@ronaldo1769 See the above MDN link, you simply need to supply a sort function to the sort method, for example: (.sort [1 7 100 3] (# (a b) (- a b)))

(for a numeric sort in ascending order)

francesco agati

@francescoagati

hello there is a mode for have hygienic macros in sibilant?

francesco agati

@francescoagati

ok resolved sorry

i have see scoped-without-source

francesco agati

@francescoagati

hello there is a mode for reload a file inside repl

the files and macro are cached

@sleepyfox

Hi @francescoagati - not as far as I'm aware - although it's supposed to be possible to delete from the require cache I can't actually get it to work in node:current :-(

francesco agati

@francescoagati

@sleepyfox thanks

Where communities thrive

People

Repo info

Activity