[Rust] Get receiver type information

[Fee0]

I just saw the developer preview for Rust and wanted to try it out.

I'm trying to find all calls to len() on a String object.

pub fn name_length(name: String) -> usize {
    name.len()
}

I expected it to work like this but there is no method for accessing the type information.
I saw other languages having this getType() function. Is Rust different here?

import rust

from MethodCallExpr call
where
  call.getIdentifier().toString() = "len" and
  call.getReceiver().getType().toString() = "String"
select call

From looking at the AST it seems I could get the TypeRepr from the function argument by tracing it back via dataflow analysis.
But I'm thinking there must be an easier way?
I'm new to codeql.

[hvitved]

Type information is currently not exposed in the public API, since we still haven't decided what that API should look like.

In the meantime, you can use the following:

from MethodCallExpr call
where
  call.getStaticTarget().getCanonicalPath() = "<core::str>::len"
select call