Generating Dynamic Patterns

[Kingloko]

Hey!
I'll apologize in advance, I'm learning rust through using egg, so I might be missing something obvious.

I can dynamically create an expression and add it to my egraph by following the examples from the documentation:

//(Bar foo 1) 
    let foo_node = ToyLang::Symbol(Symbol::from("foo"));
    let foo = expr.add(foo_node);
    let one = expr.add(ToyLang::Num(1));
    let the_bar = expr.add(ToyLang::Bar([foo, one]));

What I'd like to do is create a pattern that matches (Bar foo ?x), and I'm able to do that using .parse().unwrap()
But I'd like to programmatically generate this pattern, this is my "closest attempt"

    let mut some_pat = PatternAst::default() // I picked PatternAst because it looks like its a RecExpr and there's a Pattern constructor that uses PatternAST 
    let some_var: = "?x".parse().unwrap();
    some_pat.add(ENodeOrVar::Var(some_var));
    some_pat.add(ENodeOrVar::ENode(&foo_node));

But I get the following error: the trait bound `&ToyLang: egg::Language` is not satisfied.

Any help would be a appreciated

[mwillsey]

I believe this is the error:

some_pat.add(ENodeOrVar::ENode(&foo_node));

should be

some_pat.add(ENodeOrVar::ENode(foo_node));

Maybe with a clone. ENodeOrVar::ENode requires an owned enode.