Write on Script language about commons with other programming languages

[rrolla]

For example:

Liquidsoap unit is the same as in most of the languages void
Liquidsoap ! with in front of the exclamation mark is the same as in most of the languages & ampersand (get value by reference)
Liquidsoap function automatically return the last line in function as in most of the languages there is return keyword at end of function

Cannot understand what means that underscore _ eg commonly see like this -> _
Cannot understand what means that one tick in front of variable ' eg commonly see like this source('a)

Should be more, but this for a starting point.

Cheers

[toots]

Hi! Underscore is used to denote when a variable is not used. ' is used to denote universal types, that is types that can be anything. For instance, a function of type ('a, 'b) -> unit takes two variables of any type and returns nothing. You can write it like this:

# def f(_,_) = () end;;
f : ('a, 'b) -> unit = <fun>

[rrolla]

As I understand from the documentation:
https://www.liquidsoap.info/doc-2.0.3/language.html#lists

https://www.liquidsoap.info/doc-2.0.3/language.html#tuples

Lists and Tuples are basically arrays only difference is that lists can save the same type, but tuples can save different types?

About lists

And to access the list, we can use like in javascript Destructuring assignment https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

myList = [2, 5]
let [firstValue, secondValue] = myList

# so print these variables
print(firstValue) 
# will print 2
print(secondValue) 
# will print 5

Is there some other way to access list element for example like this myList[0]?

About tuples

Looks like here also works Destructuring assignment

myTuple = (3, "hello")
let (firstValue, secondValue) = myTuple
# so print these variables
print(firstValue) 
# will print 3
print(secondValue) 
# will print hello

Is there some other way to access the tuple element?

[toots]

This is all correct. Also, lists have unspecified number of elements while tuples have fixed number of elements.

list.nth can be used to access list elements: https://www.liquidsoap.info/doc-2.0.3/reference.html#list.nth and also list.hd for the first one. list.tail returns a list without its first element.

Tuples are more tricky because there is no generic type, each one has a different type and pre-defined number of elements. For pairs (tuples made of two elements), we have fst and snd.

[rrolla]

Thanks for the clarification @toots it's getting more transparent how it works.