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/vars.rs

@@ -21,14 +21,12 @@ use crate::cell::{Ctr};
 
 /* Mapping between a string token and a tree of Cells
  * The string token can be found in any Ctr::Symbol value
- *
- * Considerations: should I use a structure of cells for this?
- * Current thoughts: if this was a language without proper data types, yes.
+ * it is expected that the trees stored are already evaluated
  */
 pub type VTable = HashMap<String, Box<Ctr>>;
 
 pub fn define(
-    vt: Box<VTable>,
+    vt: &mut Box<VTable>,
     identifier: String,
     var_tree: Box<Ctr>
 ) {
@@ -36,14 +34,3 @@ pub fn define(
         drop(boxed_cell);
     }
 }
-
-pub fn get(
-    vt: Box<VTable>,
-    identifier: String
-) -> Option<Box<Ctr>> {
-    if let Some(c) = vt.get(&identifier) {
-        Some(*c)
-    } else {
-        None
-    }
-}