Add initial interpreter functionality (missing vars and funcs)

src/compiler.rs

@@ -1,9 +1,27 @@
+use std::io;
+
+use interpreter::interpret;
+use parser::parse;
+use tokenizer::tokenize;
+
 mod ast;
+mod interpreter;
 mod parser;
 mod token;
 mod tokenizer;
+mod value;
 
 pub fn compile(code: &str) {
     let tokens = tokenizer::tokenize(code);
     parser::parse(&tokens);
 }
+
+pub fn start_interpreter() {
+    let lines = io::stdin().lines();
+
+    for line in lines {
+        if let Ok(code) = line {
+            println!("{}", interpret(&parse(&tokenize(&code))));
+        }
+    }
+}