Started new kv impl with support for mutable cells, just the basic interpreter. Going to add the lazy bytecode interperter next

kv/src/grammar.lalrpop

@@ -0,0 +1,31 @@
+use std::str::FromStr;
+use std::rc::Rc;
+use crate::ast::Form;
+
+grammar;
+
+pub Term: Form = {
+    NUM => Form::Int(i32::from_str(<>).unwrap()),
+    SYM => Form::Symbol(<>.to_owned()),
+	"(" <ListInside?> ")" => <>.unwrap_or(Form::Nil),
+	"'" <Term> => Form::Pair(Rc::new(Form::Symbol("quote".to_owned())), Rc::new(Form::Pair(Rc::new(<>), Rc::new(Form::Nil)))),
+	"!" <h: Term> <t: Term> => {
+        h.append(Rc::new(t)).unwrap()
+     },
+};
+ListInside: Form = {
+	<Term> => Form::Pair(Rc::new(<>), Rc::new(Form::Nil)),
+	<h: Term> <t: ListInside> => Form::Pair(Rc::new(h), Rc::new(t)),
+	<a: Term> "." <d: Term> => Form::Pair(Rc::new(a), Rc::new(d)),
+}
+match {
+    "(",
+    ")",
+    ".",
+    "'",
+    "!",
+    r"[0-9]+"                                  => NUM,
+    r"[a-zA-Z+*/_=?%&|^<>-][\w+*/=_?%&|^<>-]*" => SYM,
+    r"(;[^\n]*\n)|\s+"                         => { }
+}
+