add statement-block struct
Use destructuring-bind instead of list accessors
Add optima dependency
Treat whitespace as a terminating character
Use :return rather than return-from
Add support for '.', '[', and '(' as operators
Let parse-object handle whitespace
Parse either expressions or tokens in statements
Parse parameter or array reference lists when parsing '[' and '(' ops
Remove debugging print statement
Add rules for parsing specific objects
Add array-ref-list rule (FIXUP)
Let parse-object handle whitespace (FIXUP)
Update expression? rule for new reader rules
Parse colon-like tokens as operators
Add a predicate to determine if a statement is an END statement
Add a rule for statement blocks
Read statement blocks when a colon-terminator token is encountered

Note: this is actually broken, as it doesn't handle block labels properly.