trailing comma in arrays

[akihiro17]

I would like Amber to accept trailing commas in arrays, but I'm not sure if that is a good choice for Amber.

script

let array = [
    1,
    2,
    3,
]

loop a in array {
    echo a
}

output

1
2
3

script

let array = [,]

loop a in array {
    echo a
}

output

 ERROR 
Expected expression
at test.ab:1:14


1| let array = [,]
2| 

script

let array = [1,2,3,,]

loop a in array {
    echo a
}

output

 ERROR 
Expected expression
at test.ab:1:20


1| let array = [1,2,3,,]
2| 

script

let array = []

loop a in array {
    echo a
}

output

 ERROR 
Expected array type or value before ']'
at test.ab:1:14


Eg. insert 'Num' for empty array or '1, 2, 3' for array with values

1| let array = []
2| 

[Ph0enixKM]

Can you share your motivation behind this?

[akihiro17]

I think this makes it a little easier to re-order elements in arrays.

Currently, Amber doesn't accept the script below. Therefore, to comment out the last element of an array, it is also necessary to remove the trailing space of the second-to-last element.

let array = [
    1,
    2,
    3,
    // 4,
]

loop a in array {
    echo a
}

And next time, when I want to remove the commented-out code, I need to reinsert the trailing space of the second-to-last element.

[b1ek]

Can you share your motivation behind this?

some people just like their arrays with a trailing comma. i do it sometimes too, when i want only one line to show up in git diff, not two

[b1ek]

lgtm

[Ph0enixKM]

Okay thanks for your feedback. LGTM