I have this weird behavior of patterns inside the Module construct. Note that we have
In: Module[{}, a_->x]
Out: a_ -> x
While if x is scoped, then some garbage also appears in a
In: Module[{x}, a_->x]
Out: a$_ -> x$16509
Even more, it doesn't help if x has a value,
In: Module[{x}, x=4; a_->x]
Out: a$_ -> 4
Is there any explanation for this behavior/can it be avoided in some straightforward way? Note that this does not happen in Block.
The reason this is problematic for me is because I receive a global expression with variable a, and I want it to appear in the right hand side of the pattern, i.e.
In: expr=a^2; Module[{x}, x=4; stuff[a_]->expr * x]
Out: stuff[a$_] -> 4 a^2
P.S. Mathematica 11.2.0.0
