How to pass mixin param to nth-of-type in Less?

Question

I'm setting number of columns by passing @var to my mix-in like this:

.author-card(@numberOfCards) {
    width: 100% / @numberOfCards - 2%;
    padding-bottom: 165% / @numberOfCards - 2%;
}

And I want to have a margin-right: 2% for each column except for the last in row. So, I try to do the following:

.author-card(@numberOfCards) {
    width: 100% / @numberOfCards - 2%;
    padding-bottom: 165% / @numberOfCards - 2%;
    margin-right: 2%;
    &:nth-of-type(n * @numberOfCards) {
        margin-right: 0;
    }
}

At this point Less compiler fails to compile this.

Can I achieve this in Less? Maybe there is any other way to do this?

I get the following error:

ParseError: Unrecognised input in myStylesheet.less

Answer 1

To perform selector interpolation, you need to put the variable within curly braces like below:

.author-card(@numberOfCards) {
    width: 100% / @numberOfCards - 2%;
    padding-bottom: 165% / @numberOfCards - 2%;
    margin-right: 2%;
    &:nth-of-type(@{numberOfCards}) { // note the change.
        margin-right: 0;
    }
}

Selector Interpolation - Syntax Reference