Just removes values before dot

Why this:
```coffeescript
concat = (list...) ->
  r=''.concat (list.map (i) -> "(?:#{toString i})")...
  "(?:#{r})"
```


formatted to this:
```coffeescript
concat = (list...) ->
  parts = .map (i) -> "(?:#{toString i})"
  r = .concat parts...
  "(?:#{r})"
```

??