feat: add monkey-rs

__lang/monkey-rs/src/main.rs

@@ -0,0 +1,35 @@
+mod lexer;
+mod ast;
+mod parser;
+mod object;
+mod environment;
+mod evaluator;
+mod inbuilt;
+
+use linefeed::{Interface, ReadResult};
+use crate::lexer::Lexer;
+use crate::evaluator::eval_program;
+use std::rc::Rc;
+use std::cell::RefCell;
+use crate::environment::Environment;
+
+fn main() {
+
+    let reader = Interface::new("monkey-rs").unwrap();
+    let mut env = Rc::new(RefCell::new(Environment::new()));
+
+    reader.set_prompt("monkey-rs> ").unwrap();
+
+    while let ReadResult::Input(input) = reader.read_line().unwrap() {
+        if input.eq("exit") {
+            break;
+        }
+        let lexer = Lexer::new(&*input);
+        let mut parser = parser::Parser::new(lexer);
+        let program = parser.parse_program().unwrap();
+
+        println!("{}", eval_program(program.as_ref(), &mut env));
+    }
+
+    println!("Good bye");
+}