You're not going to be able to use (with hash ...) with a local variable 'hash unless you have at least one of these:
- Fexprs. An fexpr implementation of 'with can use the complete value of 'hash as it determines how to treat the unparsed body.
- Static typing with record types, so that a macro can use the type of 'hash as it determines how to treat the unparsed body.
- Some variant of JavaScript-style scope chain semantics, in the sense that a bare variable reference means (or can mean) a field lookup in general. IMO, this would be the most straightforward to add to an Arc-3.1-like compiler, since it's a matter of compiling foo to (scope 'foo), (with foo ...) to (let ((scope (shadow (scope 'foo) scope))) ...), and other scope-related things in their own analogous ways.
