diff --git a/Cargo.lock b/Cargo.lock
index 4411f41..4368f31 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -17,6 +17,12 @@ version = "0.2.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
 
+[[package]]
+name = "anyhow"
+version = "1.0.98"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e16d2d3311acee920a9eb8d33b8cbc1787ce4a264e85f964c2404b969bdcd487"
+
 [[package]]
 name = "beef"
 version = "0.5.2"
@@ -52,6 +58,12 @@ dependencies = [
  "unicode-segmentation",
 ]
 
+[[package]]
+name = "either"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -81,11 +93,37 @@ dependencies = [
  "foldhash",
 ]
 
+[[package]]
+name = "inkwell"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e67349bd7578d4afebbe15eaa642a80b884e8623db74b1716611b131feb1deef"
+dependencies = [
+ "either",
+ "inkwell_internals",
+ "libc",
+ "llvm-sys",
+ "once_cell",
+ "thiserror",
+]
+
+[[package]]
+name = "inkwell_internals"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f365c8de536236cfdebd0ba2130de22acefed18b1fb99c32783b3840aec5fb46"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "lang"
 version = "0.1.0"
 dependencies = [
  "chumsky",
+ "inkwell",
  "logos",
 ]
 
@@ -101,6 +139,20 @@ version = "0.2.174"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
 
+[[package]]
+name = "llvm-sys"
+version = "181.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d320f9d2723c97d4b78f9190a61ed25cc7cfbe456668c08e6e7dd8e50ceb8500"
+dependencies = [
+ "anyhow",
+ "cc",
+ "lazy_static",
+ "libc",
+ "regex-lite",
+ "semver",
+]
+
 [[package]]
 name = "logos"
 version = "0.15.0"
@@ -141,6 +193,12 @@ version = "2.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
 
+[[package]]
+name = "once_cell"
+version = "1.21.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.95"
@@ -179,6 +237,12 @@ dependencies = [
  "regex-syntax 0.7.5",
 ]
 
+[[package]]
+name = "regex-lite"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53a49587ad06b26609c52e423de037e7f57f20d53535d66e08c695f347df952a"
+
 [[package]]
 name = "regex-syntax"
 version = "0.7.5"
@@ -256,6 +320,26 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.18"
diff --git a/Cargo.toml b/Cargo.toml
index f6c6272..681fc8e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,3 +6,4 @@ edition = "2024"
 [dependencies]
 logos = "0.15.0"
 chumsky = "0.10.1"
+inkwell = { version = "0.6.0", features = ["llvm18-1"] }
diff --git a/src/ast/evaluator.rs b/src/ast/evaluator.rs
index 69a52da..0765dd3 100644
--- a/src/ast/evaluator.rs
+++ b/src/ast/evaluator.rs
@@ -1,18 +1,33 @@
 use crate::ast::Expression;
 
 
-impl Expression {
-    pub fn eval(&self) -> isize {
+
+impl<'src> Expression<'src> {
+    pub fn eval(&self) -> String {
         match self {
-            Expression::Integer(n) => *n,
+            Expression::VariableName(_) => todo!(),
 
+            Expression::Integer(_) => todo!(),
+
+            Expression::Float(_) => todo!(),
+
+            Expression::String(_) => todo!(),
+
+            Expression::Bool(_) => todo!(),
+
+            Expression::Negatation(expression) => todo!(),
+
+            Expression::Add(expression, expression1) => todo!(),
+
+            Expression::Substract(expression, expression1) => todo!(),
+
+            Expression::Multiply(expression, expression1) => todo!(),
+
+            Expression::Divide(expression, expression1) => todo!(),
+
+            Expression::Var { name, rhs, then } => todo!(),
             
-            Expression::Negate(rhs) => -rhs.eval(),
-
-            Expression::Add(lhs, rhs) => lhs.eval() + rhs.eval(),
-            Expression::Substract(lhs, rhs) => lhs.eval() - rhs.eval(),
-            Expression::Multiply(lhs, rhs) => lhs.eval() * rhs.eval(),
-            Expression::Divide(lhs, rhs) => lhs.eval() / rhs.eval(),
+            Expression::Function { name, args, body, then } => todo!(),
         }
     }
 }
\ No newline at end of file
diff --git a/src/ast/mod.rs b/src/ast/mod.rs
index 24d7150..c37a3b2 100644
--- a/src/ast/mod.rs
+++ b/src/ast/mod.rs
@@ -1,12 +1,36 @@
-pub mod evaluator;
+use std::ops::Range;
 
+use crate::ast::op::Op;
+
+
+pub mod evaluator;
+pub mod op;
+
+
+/// Abstract Syntax Tree
 #[derive(Debug)]
-pub enum Expression {
-    Integer(isize),
-    Negate(Box<Expression>),
-    // Binary operators,
-    Add(Box<Expression>, Box<Expression>),
-    Substract(Box<Expression>, Box<Expression>),
-    Multiply(Box<Expression>, Box<Expression>),
-    Divide(Box<Expression>, Box<Expression>),
+pub enum Expression<'src> {
+    VariableName(&'src str),
+    Integer(i64),
+    Float(f64),
+    String(String),
+    Bool(bool),
+
+    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>>),
+    
+    Var {
+        name: &'src str,
+        rhs: Box<Expression<'src>>,
+        then: Box<Expression<'src>>,
+    },
+    Function {
+        name: &'src str,
+        args: Vec<&'src str>,
+        body: Box<Expression<'src>>,
+        then: Box<Expression<'src>>,
+    }
 }
diff --git a/src/ast/op.rs b/src/ast/op.rs
new file mode 100644
index 0000000..fce3a58
--- /dev/null
+++ b/src/ast/op.rs
@@ -0,0 +1,19 @@
+#[derive(Debug, Clone)]
+pub enum Op {
+    Add,
+    Subtract,
+    Multiply,
+    Divide,
+}
+
+impl Op {
+    pub fn eval(&self) -> String {
+        let text: &str = match self {
+           Op::Add => "+",
+           Op::Subtract => "-",
+           Op::Multiply => "*",
+           Op::Divide => "/",
+        };
+        text.to_string()
+    }
+}
\ No newline at end of file
diff --git a/src/code_generation/compiler.rs b/src/code_generation/compiler.rs
new file mode 100644
index 0000000..c5fa592
--- /dev/null
+++ b/src/code_generation/compiler.rs
@@ -0,0 +1,29 @@
+use std::collections::HashMap;
+
+use inkwell::{builder::Builder, context::Context, module::Module, values::{FunctionValue, PointerValue}};
+
+use crate::code_generation::Function;
+
+pub struct Compiler<'a, 'ctx> {
+    pub context: &'ctx Context,
+    pub builder: &'a Builder<'ctx>,
+    pub module: &'a Module<'ctx>,
+    pub function: &'a Function,
+
+    variables: HashMap<String, PointerValue<'ctx>>,
+    fn_value_opt: Option<FunctionValue<'ctx>>
+}
+
+impl<'a, 'ctx> Compiler<'a, 'ctx> {
+    /// Gets a defined function given its name.
+    #[inline]
+    fn get_function(&self, name: &str) -> Option<FunctionValue<'ctx>> {
+        self.module.get_function(name)
+    }
+    
+    /// Returns the `FunctionValue` representing the function being compiled.
+    #[inline]
+    fn fn_value(&self) -> FunctionValue<'ctx> {
+        self.fn_value_opt.unwrap()
+    }
+}
\ No newline at end of file
diff --git a/src/code_generation/mod.rs b/src/code_generation/mod.rs
new file mode 100644
index 0000000..6f66e7a
--- /dev/null
+++ b/src/code_generation/mod.rs
@@ -0,0 +1,71 @@
+pub mod compiler;
+
+// LLVM Codegen
+
+
+//--------------------------
+//  Parser
+//-------------------------
+
+use std::collections::HashMap;
+
+use logos::Lexer;
+
+use crate::tokens::Token;
+
+/// Defines a primitive expression
+#[derive(Debug)]
+pub enum Expr {
+    Binary {
+        op: char,
+        left: Box<Expr>,
+        right: Box<Expr>,
+    },
+    Call {
+        fn_name: String,
+        args: Vec<Expr>,
+    },
+    Conditional {
+        cond: Box<Expr>,
+        consequence: Box<Expr>,
+        alternative: Box<Expr>,
+    },
+    For {
+        var_name: String,
+        start: Box<Expr>,
+        end: Box<Expr>,
+        step: Option<Box<Expr>>,
+        body: Box<Expr>,
+    },
+    Number(f64),
+    Variable(String),
+    VarIn {
+        variables: Vec<(String, Option<Expr>)>,
+        body: Box<Expr>,
+    }
+
+}
+
+
+/// Defines the prototype (name and parameters) of a function
+#[derive(Debug)]
+pub struct Prototype {
+    pub name: String,
+    pub args: Vec<String>,
+    pub is_op: bool,
+    pub prec: usize,
+}
+
+/// Defines a user-defined or external function
+#[derive(Debug)]
+pub struct Function {
+    pub prototype: Prototype,
+    pub body: Option<Expr>,
+    pub is_anon: bool,
+}
+
+pub struct Parser<'a> {
+    tokens: Vec<Token<'a>>,
+    pos: usize,
+    prec: &'a mut HashMap<char, i32>,
+}
diff --git a/src/main.rs b/src/main.rs
index 96a31ae..d6c1873 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@ use crate::{parser::parser, tokens::Token};
 mod tokens;
 mod ast;
 mod parser;
+mod code_generation;
 
 fn main() {
     let lexer = Token::lexer("(1 + 1) * 3");
diff --git a/src/parser.rs b/src/parser.rs
index e7114ef..f033150 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -1,18 +1,17 @@
-use chumsky::{prelude::{just, recursive}, recursive, select, IterParser, Parser};
+use chumsky::{combinator::Or, prelude::{choice, just, recursive}, recursive, select, text::{self, ascii::ident}, IterParser, Parser};
 
 use crate::{ast::Expression, tokens::Token};
 
 
 #[allow(clippy::let_and_return)]
-/* ANCHOR: parser */
 pub fn parser<'src>(
-) -> impl Parser<'src, &'src [Token<'src>], Expression, chumsky::extra::Err<chumsky::error::Simple<'src, Token<'src>>>>
+) -> impl Parser<'src, &'src [Token<'src>], Expression<'src>, chumsky::extra::Err<chumsky::error::Simple<'src, Token<'src>>>>
 {
-    recursive(
-        |p| 
+    let expr = recursive(
+        |expr| 
         {
             let atom = {
-            let parenthesized = p
+            let parenthesized = expr
                 .clone()
                 .delimited_by(just(Token::ParenBegin), just(Token::ParenEnd));
 
@@ -25,7 +24,7 @@ pub fn parser<'src>(
 
         let unary = just(Token::Substract)
             .repeated()
-            .foldr(atom, |_op, rhs| Expression::Negate(Box::new(rhs)));
+            .foldr(atom, |_op, rhs| Expression::Negatation(Box::new(rhs)));
 
         let binary_1 = unary.clone().foldl(
             just(Token::Multiply)
@@ -52,5 +51,7 @@ pub fn parser<'src>(
         );
 
         binary_2
-    })
+    });
+
+    expr
 }
\ No newline at end of file
diff --git a/src/tokens.rs b/src/tokens.rs
index 30a5b41..ec77d9e 100644
--- a/src/tokens.rs
+++ b/src/tokens.rs
@@ -2,7 +2,7 @@ use logos::{Lexer, Logos};
 
 #[derive(Logos, Debug, Clone, PartialEq)]
 #[logos(skip r"[ \t\r\n\f]+")] // Skips whitespace
-pub enum Token<'source> {
+pub enum Token<'src> {
     #[token("false", |_| false)]
     #[token("true", |_| true)]
     Bool(bool),
@@ -37,11 +37,11 @@ pub enum Token<'source> {
     #[token("}")]
     BraceEnd,
 
-    #[regex("[0-9]+", |lex| lex.slice().parse::<isize>().unwrap())]
-    Integer(isize),
+    #[regex("[0-9]+", |lex| lex.slice().parse::<i64>().unwrap())]
+    Integer(i64),
     
     #[regex(r"[_a-zA-Z][_0-9a-zA-Z]*")]
-    Ident(&'source str),
+    Ident(&'src str),
 
     #[regex(r#""([^"\\\x00-\x1F]|\\(["\\bnfrt/]|u[a-fA-F0-9]{4}))*""#, |lex| lex.slice().to_owned())]
     String(String),
@@ -51,7 +51,7 @@ pub enum Token<'source> {
     #[token("var")]
     #[token("if")]
     #[token("else")]
-    Keyword(&'source str),
+    Keyword(&'src str),
 }