diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..1e6979e
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,130 @@
+use crate::units::Unit;
+pub mod units;
+use std::time::{Instant};
+use decimal::d128;
+
+#[derive(Clone, Debug)]
+pub enum Operator {
+  Plus,
+  Minus,
+  Multiply,
+  Divide,
+  Modulo,
+  Caret,
+  LeftParen, // lexer only
+  RightParen, // lexer only
+}
+
+#[derive(Clone, Debug)]
+pub enum UnaryOperator {
+  Percent,
+  Factorial,
+}
+
+#[derive(Clone, Debug)]
+pub enum TextOperator {
+  To,
+  Of,
+}
+
+#[derive(Clone, Debug)]
+pub enum Constant {
+  Pi,
+  E,
+}
+
+#[derive(Clone, Debug)]
+pub enum FunctionIdentifier {
+  Sqrt,
+  Cbrt,
+
+  Log,
+  Ln,
+  Exp,
+  
+  Round,
+  Ceil,
+  Floor,
+  Abs,
+
+  Sin,
+  Cos,
+  Tan,
+}
+
+#[derive(Clone, Debug)]
+pub enum LexerKeyword {
+  Per,
+  PercentChar,
+  In,
+  DoubleQuotes,
+  Mercury,
+  Hg,
+  PoundForce,
+  PoundWord,
+  Force,
+}
+
+#[derive(Clone, Debug)]
+pub enum Token {
+  Operator(Operator),
+  UnaryOperator(UnaryOperator),
+  Number(d128),
+  FunctionIdentifier(FunctionIdentifier),
+  Constant(Constant),
+  Paren, // parser only
+  Per, // lexer only
+  LexerKeyword(LexerKeyword),
+  TextOperator(TextOperator),
+  Negative, // parser only
+  Unit(units::Unit),
+}
+
+pub type TokenVector = Vec<Token>;
+
+mod lexer;
+mod parser;
+mod evaluator;
+mod lookup;
+
+pub fn eval(input: &str, allow_trailing_operators: bool, default_degree: Unit, debug: bool) -> Result<units::Number, String> {
+
+  let lex_start = Instant::now();
+
+  match lexer::lex(input, allow_trailing_operators, default_degree) {
+    Ok(tokens) => {
+      let lex_time = Instant::now().duration_since(lex_start).as_nanos() as f32;
+
+      let parse_start = Instant::now();
+      match parser::parse(&tokens) {
+        Ok(ast) => {
+          let parse_time = Instant::now().duration_since(parse_start).as_nanos() as f32;
+
+          let eval_start = Instant::now();
+          match evaluator::evaluate(&ast) {
+            Ok(answer) => {
+              let eval_time = Instant::now().duration_since(eval_start).as_nanos() as f32;
+
+              if debug == true {
+                println!("Lexed TokenVector: {:?}", tokens);
+                println!("Parsed AstNode: {:#?}", ast);
+                println!("Evaluated value: {} {:?}", answer.value, answer.unit);
+                println!("\u{23f1}  {:.3}ms lexing", lex_time/1000.0/1000.0);
+                println!("\u{23f1}  {:.3}ms parsing", parse_time/1000.0/1000.0);
+                println!("\u{23f1}  {:.3}ms evaluation", eval_time/1000.0/1000.0);
+              }
+
+              return Ok(answer)
+            },
+            Err(e) => Err(format!("Eval error: {}", e)),
+          }
+          
+        },
+        Err(e) => Err(format!("Parsing error: {}", e)),
+      }
+
+    },
+    Err(e) => Err(format!("Lexing error: {}", e)),
+  }
+  
+}
diff --git a/src/main.rs b/src/main.rs
index 2c44768..0bf39cf 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,92 +1,5 @@
-use crate::units::Unit;
-use std::time::{Instant};
-use decimal::d128;
-
-#[derive(Clone, Debug)]
-pub enum Operator {
-  Plus,
-  Minus,
-  Multiply,
-  Divide,
-  Modulo,
-  Caret,
-  LeftParen, // lexer only
-  RightParen, // lexer only
-}
-
-#[derive(Clone, Debug)]
-pub enum UnaryOperator {
-  Percent,
-  Factorial,
-}
-
-#[derive(Clone, Debug)]
-pub enum TextOperator {
-  To,
-  Of,
-}
-
-#[derive(Clone, Debug)]
-pub enum Constant {
-  Pi,
-  E,
-}
-
-#[derive(Clone, Debug)]
-pub enum FunctionIdentifier {
-  Sqrt,
-  Cbrt,
-
-  Log,
-  Ln,
-  Exp,
-  
-  Round,
-  Ceil,
-  Floor,
-  Abs,
-
-  Sin,
-  Cos,
-  Tan,
-}
-
-#[derive(Clone, Debug)]
-pub enum LexerKeyword {
-  Per,
-  PercentChar,
-  In,
-  DoubleQuotes,
-  Mercury,
-  Hg,
-  PoundForce,
-  PoundWord,
-  Force,
-}
-
-mod units;
-
-#[derive(Clone, Debug)]
-pub enum Token {
-  Operator(Operator),
-  UnaryOperator(UnaryOperator),
-  Number(d128),
-  FunctionIdentifier(FunctionIdentifier),
-  Constant(Constant),
-  Paren, // parser only
-  Per, // lexer only
-  LexerKeyword(LexerKeyword),
-  TextOperator(TextOperator),
-  Negative, // parser only
-  Unit(units::Unit),
-}
-
-pub type TokenVector = Vec<Token>;
-
-mod lexer;
-mod parser;
-mod evaluator;
-mod lookup;
+use cpc::eval;
+use cpc::units::Unit;
 
 fn main() {
   use std::env;
@@ -110,45 +23,3 @@ fn main() {
     println!("No argument supplied");
   }
 }
-
-pub fn eval(input: &str, allow_trailing_operators: bool, default_degree: Unit, debug: bool) -> Result<units::Number, String> {
-
-  let lex_start = Instant::now();
-
-  match lexer::lex(input, allow_trailing_operators, default_degree) {
-    Ok(tokens) => {
-      let lex_time = Instant::now().duration_since(lex_start).as_nanos() as f32;
-
-      let parse_start = Instant::now();
-      match parser::parse(&tokens) {
-        Ok(ast) => {
-          let parse_time = Instant::now().duration_since(parse_start).as_nanos() as f32;
-
-          let eval_start = Instant::now();
-          match evaluator::evaluate(&ast) {
-            Ok(answer) => {
-              let eval_time = Instant::now().duration_since(eval_start).as_nanos() as f32;
-
-              if debug == true {
-                println!("Lexed TokenVector: {:?}", tokens);
-                println!("Parsed AstNode: {:#?}", ast);
-                println!("Evaluated value: {} {:?}", answer.value, answer.unit);
-                println!("\u{23f1}  {:.3}ms lexing", lex_time/1000.0/1000.0);
-                println!("\u{23f1}  {:.3}ms parsing", parse_time/1000.0/1000.0);
-                println!("\u{23f1}  {:.3}ms evaluation", eval_time/1000.0/1000.0);
-              }
-
-              return Ok(answer)
-            },
-            Err(e) => Err(format!("Eval error: {}", e)),
-          }
-          
-        },
-        Err(e) => Err(format!("Parsing error: {}", e)),
-      }
-
-    },
-    Err(e) => Err(format!("Lexing error: {}", e)),
-  }
-  
-}