Checking if a function in the AST is defined in Engine

[dilawar]

I have rhai::Engine with a few custom functions added to it. Now I get an expression that uses these functions. This expression may also contains function that may not be in the engine (could be a typo etc.). Can I check if an ast has a function which is not defined in the Engine.

Essentially,

for f in ast.iter_functions() {
      // how to check if `f` is available in the engine. 
 }

[dilawar]

Ah, found it https://docs.rs/rhai/1.19.0/rhai/struct.Engine.html#method.gen_fn_signatures