Vau lisp?

Fexprs as the basis of Lisp function application or $vau : the ultimate abstraction by John Shutt

The core idea I implement here takes inspiration from this dissertation. $vau is a reworking of f-exprs (essentially, first-class macros) on which all other forms can be implemented. It reframes lisp evaluation from implicit evaluation with explicit quoting to one of implicit quoting with explicit evaluation.

Effectively, applying a vau expression acts as a tree rewrite rule. Evaluation occurs as a result of the wrap primitive, which converts a combiner into an applicative, evaluating its arguments before applying the combiner.

The primitives of the language are:

• $def! - definition of one name to one value
• eq? - identity comparison of just two values
• $vau - binds parameters to a single name, unpacking is manual
• wrap - wrap a combiner as an applicative
• unwrap - remove an applicative wrapping
• car/cdr - operators for decomposing pairs
• make-environment - create a new environment
• eval - evaluate an expression in an environment
• select - if a value is true, return the first argument, else the second

Goals

• Core language and REPL in Python
• Meta-circular evaluator
• Self-compile to wasm WAT format