Parent Selector ('&') will not combine non-keywords

[rayanth]

Ref https://lesscss.org/features/#parent-selectors-feature there is no indication that there needs to be a - to join two words into one, like their example shows.

In a shortened version of their example this:

.button {
    &-OK {
        background-image: url("ok.png");
    }
}

Should compile to :

.button-OK {
  background-image: url("ok.png");
}

This works properly in lesscpy.

What does NOT work, is the following:

.button {
    &OK {
        background-image: url("ok.png");
    }
}

(notice the removal of the -)
Should compile to:

.buttonOK {
  background-image: url("ok.png");
}

Instead, in lesscpy, it results in:

Syntax Error, token: `css_ident`, `ok`
Syntax Error, token: `t_bclose`, `}`

In other LESS parsers, this compiles fine.

Note that if the second word is a valid DOM element, e.g. 'Div', it will work in lesscpy:

.button {
    &Div {
        background-image: url("ok.png");
    }
}

correctly results in:

.buttonDiv {
  background-image: url("ok.png");
}