Add optional argument to split

[Jason2605]

Well detailed description of the change :

This PR adds a new optional argument to str.split() which determines the amount of times a string will actually be broken up by the delimiter. This allows us to keep the delimiter within the string after a certain amount of occurrences have already been found.

E.g

"Dictu is awesome!".split(" ", 0); // ['Dictu is awesome!']
"Dictu is awesome!".split(" ", 1); // ['Dictu', 'is awesome!']
"Dictu is awesome!".split(" ", 2); // ['Dictu', 'is', 'awesome!']

Type of change:

• Bug fix

• New feature

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Housekeeping

• Tests have been updated to reflect the changes done within this PR (if applicable).

• Documentation has been updated to reflect the changes done within this PR (if applicable).

Note

This may come in useful with regards to #473

[briandowns]

I'm curious about your thoughts on this:

Keep basic functionality and expectations the same.

"Dictu is awesome!".split(" "); // ['Dictu', 'is', 'awesome!']

Add another method, like Go, to indicate the number of times to split.

"Dictu is awesome!".splitN(" ", 1); // ['Dictu', 'is awesome!']
"Dictu is awesome!".splitN(" ", 2); // ['Dictu', 'is', 'awesome!']

or

Have value indicating all instances of the seperator.

"Dictu is awesome!".split(" ", -1); // ['Dictu', 'is', 'awesome!']

[Jason2605]

Hey! Thanks for the comments!

Add another method, like Go, to indicate the number of times to split.

I think another method will probably end up with a lot of code duplication or macro abuse which are never fun to deal with (neither are strings in C at the best of times ;( )

.split(delim, occur) is also how it is in Python 😄

Have value indicating all instances of the separator.

This is something I don't mind too much about. Checking in Python a negative number seems to make it ignore the count and just split by all occurrences of the delimiter (like how you propose with -1). The current implementation treats negative numbers as not wanting to split (so essentially the same as passing 0). Probably a good idea as it means you can have a negative number as a default rather than having to have two flows in user code with:

// Flow 1
const count = cond ? 3 : -1;
".........".split(",", count);

// Flow 2
if (cond) {
    ".........".split(",");
} else {
    ".........".split(",", 3);
}

[Jason2605]

@briandowns I've updated the PR to make negative numbers split all occurrences now, thanks for the thought!

[briandowns]

LGTM!