How to take several values out of a large expression?

Question

Background: Consider the following graphics directive.

    EdgeForm[
     Directive[Thickness[Large], 
     Dashing[{Small, Small}], 
     Opacity[0.1`], 
     RGBColor[0, 0, 1]]]

In a Manipulate I want to interactively change Thickness, Dashing, Opacity and Color of the edges of Polygons in a pattern. So, for each of them I will have to create a control. The EdgeForm is stored in Excel =as is=. So I will need to extract the values which will become the starting values for the controls out of the EdgeForm above, i.e.:

    Large, 
    {Small, Small}, 
    0.1, 
    RBGColor [0,0,1]

for the four controls respectively.

My strategy was to ToString[EdgeForm[ ...everything ] and then do string manipulations on them but that turned out to become a lot of ( messy, still not working ) code. Considering this is Mathematica ( I thought that ) there must be a simple way to get the values out of that EdgeForm.

Question: How to change the EdgeForm above to {Large, {Small, Small}, 0.1, RBGColor [0,0,1] }. Needless to say that the values change per pattern, i.e. Tiny, Large, etc.

Answer 1

As @Szabolcs points out in the comments, you can always use Part or Replace regardless what head your expression has. I personally prefer ReplaceAll in cases such as this because I find it easier to tell what I intended with my code when I dig it up months or years later.

ef = 
  EdgeForm[Directive[Thickness[Large], Dashing[{Small, Small}], 
    Opacity[0.1`], RGBColor[0, 0, 1]]];

ef /. 
 EdgeForm[Directive[Thickness[t_], Dashing[d_], Opacity[o_], 
    col_]] :> {t, d, o, col}

==> {Large, {Small, Small}, 0.1, RGBColor[0, 0, 1]}