diff --git a/.gitignore b/.gitignore
index 68f7583..c7e89de 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /target
-*.sh
\ No newline at end of file
+*.sh
+sample.akai
\ No newline at end of file
diff --git a/src/language_frontend/abstract_syntax_tree/ast.rs b/src/language_frontend/abstract_syntax_tree/ast.rs
index 8e2394a..53603de 100644
--- a/src/language_frontend/abstract_syntax_tree/ast.rs
+++ b/src/language_frontend/abstract_syntax_tree/ast.rs
@@ -2,19 +2,23 @@
 
 #[derive(Debug)]
 pub enum Expression<'src> {
+    // Identifier
     Ident(&'src str),
 
+    // Types
     Integer(i64),
     Float(f64),
     String(String),
     Bool(bool),
 
+    // Operations
     Negatation(Box<Expression<'src>>),
     Add(Box<Expression<'src>>, Box<Expression<'src>>),
     Substract(Box<Expression<'src>>, Box<Expression<'src>>),
     Multiply(Box<Expression<'src>>, Box<Expression<'src>>),
     Divide(Box<Expression<'src>>, Box<Expression<'src>>),
 
+    // Keywords
     Var {
         name: &'src str,
         rhs: Box<Expression<'src>>,
@@ -37,16 +41,24 @@ pub fn eval<'src>(
     funcs: &mut Vec<(&'src str, &'src [&'src str], &'src Expression<'src>)>,
 ) -> Result<f64, String> {
     match expr {
-        Expression::Ident(_) => todo!(),
+        Expression::Ident(name) => {
+            if let Some((_, val)) = vars.iter().rev().find(|(var, _)| var == name) {
+                Ok(*val)
+            } else {
+                Err(format!("Cannot find variable `{name}` in scope"))
+            }
+        },
 
-        Expression::Integer(x) => Ok((*x) as f64),
+        // Types
+        Expression::Integer(x) => Ok((*x) as f64), // todo
 
-        Expression::Float(_) => todo!(),
+        Expression::Float(x) => Ok(*x),
 
         Expression::String(_) => todo!(),
 
         Expression::Bool(_) => todo!(),
 
+        // Operations
         Expression::Negatation(lhs) => todo!(),
 
         Expression::Add(lhs, rhs) => Ok(eval(lhs, vars, funcs)? + eval(rhs, vars, funcs)?),
@@ -57,14 +69,26 @@ pub fn eval<'src>(
 
         Expression::Divide(lhs, rhs) => Ok(eval(lhs, vars, funcs)? / eval(rhs, vars, funcs)?),
 
-        Expression::Var { name, rhs, then } => todo!(),
+        // Keywords
+        Expression::Var { name, rhs, then } => {
+            let rhs = eval(rhs, vars, funcs)?;
+            vars.push((*name, rhs));
+            let output = eval(then, vars, funcs);
+            vars.pop();
+            output
+        },
 
         Expression::Function {
             name,
             args,
             body,
             then,
-        } => todo!(),
+        } => {
+            funcs.push((name, args, body));
+            let output = eval(then, vars, funcs);
+            funcs.pop();
+            output
+        },
 
         Expression::Unit => todo!(),
     }
diff --git a/src/language_frontend/abstract_syntax_tree/mod.rs b/src/language_frontend/abstract_syntax_tree/mod.rs
index a2d9679..3c19eab 100644
--- a/src/language_frontend/abstract_syntax_tree/mod.rs
+++ b/src/language_frontend/abstract_syntax_tree/mod.rs
@@ -1,2 +1,3 @@
 pub mod ast;
 pub mod op;
+pub mod parser;
diff --git a/src/language_frontend/parser.rs b/src/language_frontend/abstract_syntax_tree/parser.rs
similarity index 85%
rename from src/language_frontend/parser.rs
rename to src/language_frontend/abstract_syntax_tree/parser.rs
index e4bed75..5e0203e 100644
--- a/src/language_frontend/parser.rs
+++ b/src/language_frontend/abstract_syntax_tree/parser.rs
@@ -1,9 +1,5 @@
 use chumsky::{
-    IterParser, Parser,
-    combinator::Or,
-    prelude::{choice, just, recursive},
-    recursive, select,
-    text::{self, ascii::ident},
+    combinator::Or, prelude::{choice, just, recursive}, recursive, select, select_ref, text::{self, ascii::ident, whitespace}, IterParser, Parser
 };
 
 use crate::{language_frontend::abstract_syntax_tree::ast::Expression, language_frontend::lexer::tokens::Token};
@@ -12,8 +8,8 @@ use crate::{language_frontend::abstract_syntax_tree::ast::Expression, language_f
 
 #[allow(clippy::let_and_return)]
 pub fn parser<'src>() -> impl Parser<'src, &'src [Token<'src>], Expression<'src>> {
-    let ident = select! {
-        Token::Ident(ident) => ident
+    let ident = select_ref! {
+        Token::Ident(ident) => *ident
     };
 
     let keyword = |kw: &'static str| {
@@ -41,6 +37,8 @@ pub fn parser<'src>() -> impl Parser<'src, &'src [Token<'src>], Expression<'src>
             .repeated()
             .foldr(atom, |_op, rhs| Expression::Negatation(Box::new(rhs)));
 
+        // "Punktrechnung vor Strichrechnung :nerd:"
+
         let binary_1 = unary.clone().foldl(
             just(Token::Multiply)
                 .or(just(Token::Divide))
@@ -70,9 +68,9 @@ pub fn parser<'src>() -> impl Parser<'src, &'src [Token<'src>], Expression<'src>
 
     let decl = recursive(|decl| {
         let r#var = keyword("var")
-            .ignore_then(ident.clone())
+            .ignore_then(ident)
             .then_ignore(eq.clone())
-            .then(decl.clone())
+            .then(expr.clone())
             .then(decl.clone())
             .map(|((name, rhs), then)| Expression::Var {
                 name,
@@ -82,10 +80,10 @@ pub fn parser<'src>() -> impl Parser<'src, &'src [Token<'src>], Expression<'src>
 
         let r#fun = keyword("fun")
             .ignore_then(ident.clone())
-            .then(ident.clone().repeated().collect())
+            .then(ident.repeated().collect::<Vec<_>>())
             .then_ignore(eq.clone())
-            .then(decl.clone())
-            .then(decl.clone())
+            .then(expr.clone())
+            .then(decl)
             .map(|(((name, args), body), then)| Expression::Function {
                 name,
                 args,
diff --git a/src/language_frontend/lexer/tokens.rs b/src/language_frontend/lexer/tokens.rs
index 3d8ff21..7a5cace 100644
--- a/src/language_frontend/lexer/tokens.rs
+++ b/src/language_frontend/lexer/tokens.rs
@@ -37,9 +37,12 @@ pub enum Token<'src> {
     #[token("}")]
     BraceEnd,
 
-    #[regex("[0-9]+", |lex| lex.slice().parse::<i64>().unwrap())]
+    #[regex(r"[+-]?[0-9]+", |lex| lex.slice().parse::<i64>().unwrap(), priority = 3)]
     Integer(i64),
 
+    #[regex(r"[+-]?([0-9]*[.])?[0-9]+", |lex| lex.slice().parse::<f64>().unwrap())]
+    Float(f64),
+
     #[regex(r"[_a-zA-Z][_0-9a-zA-Z]*")]
     Ident(&'src str),
 
diff --git a/src/language_frontend/mod.rs b/src/language_frontend/mod.rs
index 8c28b19..0d2d3fd 100644
--- a/src/language_frontend/mod.rs
+++ b/src/language_frontend/mod.rs
@@ -1,3 +1,2 @@
 pub mod abstract_syntax_tree;
 pub mod lexer;
-pub mod parser;
diff --git a/src/main.rs b/src/main.rs
index 9c2d4c8..d8f741c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,11 +1,11 @@
 use chumsky::Parser;
 use logos::Logos;
 
-use crate::language_frontend::abstract_syntax_tree;
 use crate::{
-    language_frontend::lexer::tokens::Token, language_frontend::parser::parser};
+    language_frontend::lexer::tokens::Token, language_frontend::abstract_syntax_tree::parser::parser};
 
 use crate::language_frontend::abstract_syntax_tree::ast::{eval, Expression};   
+
 mod language_frontend;
 
 /*
@@ -17,7 +17,8 @@ Simple Compiler -> 4 Stages:
 */
 
 fn main() {
-    let lexer = Token::lexer("1 + 1 * 3");
+    let sourcecode = std::fs::read_to_string("sample.akai").unwrap();
+    let lexer = Token::lexer(&sourcecode);
 
     let mut tokens = vec![];
     for (token, span) in lexer.spanned() {
@@ -30,19 +31,6 @@ fn main() {
         }
     }
 
-    /* 
-    match parser().parse(&tokens).into_result() {
-        Ok(expr) => match eval(&ast, &mut Vec::new(), &mut Vec::new()) {
-            Ok(output) => println!("{output}"),
-            Err(eval_err) => println!("Evaluation error: {eval_err}"),
-        }
-        Err(e) => {
-            println!("parse error: {:#?}", e);
-            return;
-        }
-    }; */
-
-
     match parser().parse(&tokens).into_result() {
         Ok(ast) => match eval(&ast, &mut Vec::new(), &mut Vec::new()) {
             Ok(output) => println!("{output}"),