pub type EvalStrHook = fn(code: &str, env: &Env) -> Result<Value, String>;Expand description
Executes a code string against an immutable snapshot of the env and returns ans.
Used by call_builtin when eval() appears in expression context
(e.g. y = eval('2+2')). Env mutations inside the string do not persist —
the hook executes against a clone. For env-mutating eval, use eval() as a
standalone statement.