WIP commit:

* Fix up project structures
* combine vars and funcs table
* make a place for old code that may be useful to reference
* singleton pattern for sym table

Commentary:
When this change is finally finished I promise to use feature branches
from here on out

legacy_snippets/initial_rough_spaghetti_implementation/append.rs

@@ -0,0 +1,70 @@
+/* relish: versatile lisp shell
+ * Copyright (C) 2021 Aidan Hahn
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+use crate::func::{Args, FTable, Function, Operation};
+use crate::segment::{circuit, list_append, list_idx, new_ast, Ast, Ctr};
+use crate::vars::VTable;
+use std::cell::RefCell;
+use std::rc::Rc;
+
+pub fn get_append() -> Function {
+    return Function {
+        name: String::from("append"),
+        loose_syms: false,
+        eval_lazy: false,
+        args: Args::Lazy(-1),
+        function: Operation::Internal(Box::new(
+            |a: Ast, _b: Rc<RefCell<VTable>>, _c: Rc<RefCell<FTable>>| -> Ctr {
+                let ptr = list_idx(a.clone(), 0);
+                match ptr {
+                    Ctr::Seg(ref c) => {
+                        let acpy = a.clone();
+                        match acpy.borrow().cdr.clone() {
+                            Ctr::Seg(cn) => {
+                                // append to list case
+                                if !circuit(cn, &mut |arg: &Ctr| -> bool {
+                                    list_append(c.clone(), arg.clone());
+                                    return true;
+                                }) {
+                                    eprintln!(
+                                        "get_append circuit loop should not have returned false"
+                                    );
+                                }
+                            }
+                            _ => {
+                                eprintln!("get_append args somehow not in standard form");
+                            }
+                        }
+
+                        return ptr;
+                    }
+                    _ => {
+                        let n = new_ast(Ctr::None, Ctr::None);
+                        if !circuit(a, &mut |arg: &Ctr| -> bool {
+                            list_append(n.clone(), arg.clone());
+                            return true;
+                        }) {
+                            eprintln!("get_append circuit loop should not have returned false");
+                        }
+
+                        return Ctr::Seg(n);
+                    }
+                }
+            },
+        )),
+    };
+}