This content originally appeared on DEV Community and was authored by Ken Okabe
Grouping operator ( ) in JavaScript
The grouping operator
( )controls the precedence of evaluation in expressions.
does Not differ from Haskell or other programming languages. (there is a minor exception as a byproduct of their main purpose in Lisp/Clojure)
In other words, grouping operator ( ) in every language shares the common functionality to compose Dependency graph
In mathematics, computer science and digital electronics, a dependency graph is a directed graph representing dependencies of several objects towards each other. It is possible to derive an evaluation order or the absence of an evaluation order that respects the given dependencies from the dependency graph.
and the functionality of Grouping operator ( ) itself is not affected by a evaluation strategy
Perhaps we can share the code below:
-
f() * (g() + h())
to discuss the topic here, but not limited to the example.
Haskell
In the code in Haskell where the evaluation strategy is Lazy / Call-by-need
https://en.wikipedia.org/wiki/Lazy_evaluation
In this code, according to the call-by-need, the evaluation order of f g h is
h(1) -> f(1) -> g(1)
In this code, according to the call-by-need, the evaluation order of f g h is
f(1) -> g(1) -> h(1)
JavaScript
//function definition
const f = a => a + 1;
const g = a => a + 2;
const h = a => a + 3;
//calling functions
console.log(
(f(1) * g(1)) + h(1)
); //10
console.log(
f(1) * (g(1) + h(1))
); //14
In this code, according to the eager-evaluation the evaluation order of f g h is
f(1) -> g(1) -> h(1)
in both cases.
Either way, the regardless the evaluation strategies, since the dependency graph composed with Groping operator() and + * stays identical, the final evaluated value is also identical.
This content originally appeared on DEV Community and was authored by Ken Okabe
Ken Okabe | Sciencx (2021-09-30T20:27:34+00:00) Does the functionality of Grouping operator () in JavaScript differ from Haskell or other programming languages?. Retrieved from https://www.scien.cx/2021/09/30/does-the-functionality-of-grouping-operator-in-javascript-differ-from-haskell-or-other-programming-languages/
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