SyntaxInformation cannot reproduce syntax coloring of Block

Question

Is there any way to have the same syntax coloring with SyntaxInformation that Block has?

SyntaxInformation[func] = {"ArgumentsPattern" -> {{__}, _},
                        "LocalVariables" -> {"Solve", {1, Infinity}}};
func[vars : {__}, body_] := {};

After evaluating the above definition, the following two lines have different coloring:

func[{parameter, variable, constant = 0}, parameter + variable + constant]

Block[{parameter, variable, constant = 0}, parameter + variable + constant]

As you can notice, any local variable with an initial value is not highlighted as local. I use the default syntax coloring, no changes were applied. SyntaxInformation accepts the following values: {"Table", "Solve", "Integrate", "Limit", "Plot", "Manipulate"} none of which produces the same behaviour as Block does. Perhaps someone knows about an undocumented option value?

Answer 1

Unfortunately, the current answer is "you can't". These are hard coded into the FE. Module/With, in particular, are not treated as local variables since they are really lexically scoped. If you look carefully, you'll see they are a slightly different color, and if you look in the syntax coloring prefs you'll see they have a dedicated section.

One of our own iternal wishlist items is to unify the implementation of these different color schemes as well as allowing new rules to be written in Wolfram Language so users can define they own local variable rules. As with everything, this is just one of many competing features. If this sounds like something you would want, I suggest you contact support with your request. The more evidence we have that users are interested in this, the more likely it is we will spend the resources needed to make it happen.