diff --git a/src/lib.rs b/src/lib.rs
index 88d2720..e87a07f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,9 @@
-pub mod lexer;
-pub mod errors;
+mod lexer;
 mod parser;
 
+pub use lexer::errors as lexer_errors;
+pub use parser::errors as parser_errors;
+
 pub fn calculate(expression: &str) -> Result<f64, parser::errors::ParserErrors> {
     Ok(parser::parse(lexer::Lexer::new(expression))?)
 }
diff --git a/src/main.rs b/src/main.rs
index a49b4bc..6047c9a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,21 @@
-use s5_cb_calculator::lexer::Lexer;
+use std::io;
+use std::io::Write;
+use s5_cb_calculator::calculate;
 
 fn main() {
     println!("Hi there! Welcome to OverComplicatedCalculator v1.0!");
     println!("To have OCC calculate something, just type it in!");
+    loop {
+        print!(" |> ");
+        io::stdout().flush().expect("Couldn't flush output!");
+        let mut expression = String::new();
+        io::stdin()
+            .read_line(&mut expression)
+            .expect("Couldn't read line, please try again later!");
+        match calculate(&expression.trim()) {
+            Ok(res) => println!("ans: {}", res),
+            Err(err) => println!("Expression couldn't be parsed: {:?}", err)
+        }
+    }
 
 }