Passing a variable list through .for loop using Le

Question

I have been using a Less mixin which makes looping in Less, less verbose and is really handy: https://github.com/seven-phases-max/less.curious/

I upgraded from Less 2.6.0 to Less 2.6.1 and now the Less will not compile.

Here's the Less code:

// ............................................................
// .for

.for(@i, @n) {.-each(@i)}
.for(@n)     when (isnumber(@n)) {.for(1, @n)}
.for(@i, @n) when not (@i = @n)  {
.for((@i + (@n - @i) / abs(@n - @i)), @n);
}

// ............................................................
// .for-each

.for(@array)   when (default()) {.for-impl_(length(@array))}
.for-impl_(@i) when (@i > 1)    {.for-impl_((@i - 1))}
.for-impl_(@i) when (@i > 0)    {.-each(extract(@array, @i))}

@gray-base: #000;
@gray-darker: #222;
@gray-dark: #333;
@gray: #555;
@gray-light: #777;
@gray-lighter: #eee;

@gray-type:
 gray,
 gray-base,
 gray-dark,
 gray-darker,
 gray-light,
 gray-lighter;

.gray-type {
    // Mixin to generate the gray font colours for p tags in the font stacks.
    .for(@gray-type); .-each(@name) {
        .@{name} {
            color: @@name;
        }
    }   
}

Here's the expected output:

.gray-type .gray {
  color: #555;
}
.gray-type .gray-base {
  color: #000;
}
.gray-type .gray-dark {
  color: #333;
}
.gray-type .gray-darker {
  color: #222;
}
.gray-type .gray-light {
  color: #777;
}
.gray-type .gray-lighter {
  color: #eee;
}

After upgrading to Less 2.6.1 I get the following error:

>> SyntaxError: variable @[object Object],[object Object] is undefined in less/style.less on line 41, column 3:
>> 40       // Mixin to generate the gray font colours for p tags in the font stacks.
>> 41       .for(@gray-type); .-each(@name) {
>> 42           .@{name} {
Warning: Error compiling less/style.less Use --force to continue.

I think the problem is related to the hyphens being stripped from the variables during compilation, therefore making the variables passed though the list invalid.

Any help would be greatly appreciated.