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I’m not super familiar with Clojure, but I tried to read through the link you shared. I certainly could be missing something, what can Clojure’s destructuring d

I’m not super familiar with Clojure, but I tried to read through the link you shared. I certainly could be missing something, what can Clojure’s destructuring do that JavaScript cannot?

deleted 4y ago
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joshlemer 4y ago
I'm not sure what are all the differences but one I have come across that you can't do in JS is to simultaneously destructure an object/array, and at the same time bind a name to the entire object/array. For instance here in Clojure we can extract the a,b,c keys from the passed map, and at the same time bind the whole map to the variable bar. (defn foo [{:keys [a b c] :as bar}] [bar a b c]) (foo {:a 1 :b 2 :c 3}) ;; => [{:a 1, :b 2, :c 3} 1 2 3] in JS you can do const f = ({a,b,c}) => [???, a, b, c] but how do you bind to the whole object as well?
- joshlemer 4y ago
  Oh I thought of an other one. In Clojure "objects" are actually maps, which can have non-string keys as well. That means you can destructure maps which have non-string (or, technically, keyword) keys as well: (defn foo [{a 1 b 2 :as bar}] [bar a b]) (foo {1 "hi" 2 "world" 3 "!"}) ;; => [{1 "hi", 2 "world", 3 "!"} "hi" "world"] In JS of course you can have Maps with non-string keys, but destructuring doesn't work on them. Plus you have other issues like arrays in JS having equality defined by reference rather than value, making maps less useful overall.
  - __ryan__ 4y ago
    Ah, I see. Yeah, you would have to bind the argument to a name then destructure it separately: let foo = (bar) => { let {a, b, c} = bar return [bar, a, b, c] } foo({ a: 1, b: 2, c: 3 }) // => [ { a: 1, b: 2, c: 3 }, 1, 2, 3 ] Though JavaScript object keys are strictly strings and symbols, you can destructure dynamic keys like so: let foo = (bar) => { let {[1]: a, [2]: b} = bar return [bar, a, b] } foo({ 1: "hi", 2: "world", 3: "!" }) // => [ { '1': 'hi', , '2': 'world', '3': '!' }, 'hi' 'world' ]

I’m not super familiar with Clojure, but I tried to read through the link you shared. I certainly could be missing something, what can Clojure’s destructuring do that JavaScript cannot?

deleted 4y ago

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joshlemer 4y ago

I'm not sure what are all the differences but one I have come across that you can't do in JS is to simultaneously destructure an object/array, and at the same time bind a name to the entire object/array. For instance here in Clojure we can extract the a,b,c keys from the passed map, and at the same time bind the whole map to the variable bar. (defn foo [{:keys [a b c] :as bar}] [bar a b c]) (foo {:a 1 :b 2 :c 3}) ;; => [{:a 1, :b 2, :c 3} 1 2 3] in JS you can do const f = ({a,b,c}) => [???, a, b, c] but how do you bind to the whole object as well?

joshlemer 4y ago
Oh I thought of an other one. In Clojure "objects" are actually maps, which can have non-string keys as well. That means you can destructure maps which have non-string (or, technically, keyword) keys as well: (defn foo [{a 1 b 2 :as bar}] [bar a b]) (foo {1 "hi" 2 "world" 3 "!"}) ;; => [{1 "hi", 2 "world", 3 "!"} "hi" "world"] In JS of course you can have Maps with non-string keys, but destructuring doesn't work on them. Plus you have other issues like arrays in JS having equality defined by reference rather than value, making maps less useful overall.
- __ryan__ 4y ago
  Ah, I see. Yeah, you would have to bind the argument to a name then destructure it separately: let foo = (bar) => { let {a, b, c} = bar return [bar, a, b, c] } foo({ a: 1, b: 2, c: 3 }) // => [ { a: 1, b: 2, c: 3 }, 1, 2, 3 ] Though JavaScript object keys are strictly strings and symbols, you can destructure dynamic keys like so: let foo = (bar) => { let {[1]: a, [2]: b} = bar return [bar, a, b] } foo({ 1: "hi", 2: "world", 3: "!" }) // => [ { '1': 'hi', , '2': 'world', '3': '!' }, 'hi' 'world' ]