What you are trying to do is generate code (a function definition) programmatically.
There are several techniques to programmatically generate code. The main tool we need is injecting held expressions into other held expression. The usual way to do it is using With:
tmp2 = x^2 + 1;
With[{exp...
Using global variables the following turns an "expression" into a Function:
expr = 2 x;
Function[x, Evaluate[expr]]
Of course this doesn't work if for some reason a value is assigned to x. Thus, I want to turn expr into a Function iside a Module. But it seems like there is a scoping problem:
...
I have the following pair of things:
ClearAll[foo, labeledFoo];
labeledFoo = {"FooBarBazQuux", foo};
This works like you'd expect:
labeledFoo /. hdr_String :>
StringReplace[hdr, l_?LowerCaseQ ~~ U_?UpperCaseQ :> l <> " " <> U]
(* {"Foo Bar Baz Quux", foo} *)
So does this:
labeledFo...
I feel like I must be missing something simple and obvious here, but this has me scratching my head.
This works as expected:
list = {f[a], f[b]};
Cases[list, f[x_] :> x] -> Position[list, f[_]]
(* {a, b} -> {{1}, {2}} *)
However, this does not:
fun[list_] := Cases[list, f[x_] :> x] -> Posit...
