Enum TraversalInterrupt

pub enum TraversalInterrupt {
    ReturnValue(Rc<Value>),
    Error(Error),
}

Represents an interruption in traversal of the AST.

The reasons traversal may be interrupted are:

1. An error in encountered, in which case backtrack all the way up the call stack and return the error to the caller of the eval_program() function.
2. Or, a Return statement in encountered.

In the case of a Return statement, the code backtracks up the call stack to the point where the function containing the Return statement was called, and hands over the return value to the caller. If the return statement was used outside of a function, and the code reaches the end of the call stack, it is treated as an error.

Variants

ReturnValue(Rc<Value>)

Error(Error)