Module syntax 

Abstract syntax and source-position newtypes.

Spike 4 extends the spike-3 grammar with two non-local control-flow forms: Expr::Throw raises an exception carrying any runtime value, and Expr::TryCatch catches a thrown value into a let-style binder around the handler. Every other reduction form is unchanged; the propagation of a thrown value is purely a property of the evaluator’s Outcome return type, not of the syntax tree.

Structs

Position

A byte offset into the source string.

VarName

A variable or property identifier.

Enums

Expr

The abstract syntax tree.