Added Function Tables

- Ftable struct
- CallFunction procedure
- Refactors to Cell, Ctr (consequently to lex too)
- More recursive routines in Cell

src/lex.rs

@@ -16,7 +16,7 @@
  */
 
 use std::boxed::Box;
-use crate::cell::{Ctr, append, Cell};
+use crate::cell::{Ctr, Cell};
 
 const UNMATCHED_STR_DELIM: &str = "Unmatched string delimiter in input";
 const UNMATCHED_LIST_DELIM: &str = "Unmatched list delimiter in input";
@@ -161,24 +161,24 @@ fn process(document: String) -> Result<Box<Cell>, String> {
             let mut obj;
             if token.len() > 0 {
                 if is_str {
-                    obj = Ctr::STRING(token);
+                    obj = Ctr::String(token);
                     is_str = false;
                 } else if token == "true" {
-                    obj = Ctr::BOOL(true);
+                    obj = Ctr::Bool(true);
                 } else if token == "false" {
-                    obj = Ctr::BOOL(false);
+                    obj = Ctr::Bool(false);
                 } else if let Ok(i) = token.parse::<i128>() {
-                    obj = Ctr::INTEGER(i);
+                    obj = Ctr::Integer(i);
                 } else if let Ok(f) = token.parse::<f64>() {
-                    obj = Ctr::FLOAT(f);
+                    obj = Ctr::Float(f);
                 } else if let Some(s) = tok_is_symbol(&token) {
-                    obj = Ctr::SYMBOL(s);
+                    obj = Ctr::Symbol(s);
                 } else {
                     return Err(format!("Unparsable token:{}", token));
                 }
 
                 token = String::new();
-                append(&mut current_cell_ref, obj);
+                current_cell_ref.append(obj);
             }
 
             if alloc_list {
@@ -188,9 +188,9 @@ fn process(document: String) -> Result<Box<Cell>, String> {
                 }
 
                 // shortening this will lead to naught but pain
-                obj = Ctr::CELL(Box::new(*current_cell_ref));
+                obj = Ctr::Cell(Box::new(*current_cell_ref));
                 current_cell_ref = ref_stack.pop().unwrap();
-                append(&mut current_cell_ref, obj);
+                current_cell_ref.append(obj);
             }
 
             ref_stack.push(current_cell_ref);