in progress commit

- fixed errors in func and vars blocking testing
- use box references in call and eval
Still need to fix the tests themselves....

src/lib.rs

@@ -23,8 +23,10 @@ mod vars;
 
 pub mod ast {
     pub use crate::cell::{Cell, Ctr, cons, cell_as_string};
-    pub use crate::lex::{lex};
-    pub use crate::func::{Function, Operation, FTable};
+    pub use crate::lex::lex;
+    pub use crate::func::{Function, Operation, FTable, Args,
+                          InternalOperation, ExternalOperation,
+                          declare};
     pub use crate::vars::VTable;
-    pub use crate::eval::{eval};
+    pub use crate::eval::eval;
 }