There you are.

1> supports negative numbers inside the trigonometric functions, like sin(-30) for example.
2> calculates directly the contents of the argument of the trigonometric function (still not using $stript).

alias parser {
  return $regsubex($1-,/((sin|asin|acos|atan|cos|tan|log|sqrt)\\\\050(-?\\\\d+(?:\\\\.\\\\d+)?)\\\\051)/gx,$($\\\\2($calc(\\\\3)) $+ .deg,2))
}

Cordialement :o)