diff --git a/CMakeLists.txt b/CMakeLists.txt
index 431de19..9d0e055 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,6 @@ project(pl VERSION 0.0.1 LANGUAGES C CXX)
 
 set(CMAKE_CXX_STANDARD 23)
 set(SOURCES
-    src/ir.cpp
     src/main.cpp
 )
 
diff --git a/include/codegen/fasm_stack.hpp b/include/codegen/fasm_stack.hpp
index ee25f4a..7f93e47 100644
--- a/include/codegen/fasm_stack.hpp
+++ b/include/codegen/fasm_stack.hpp
@@ -68,7 +68,7 @@ private:
                 auto param_slot = m_allocator->Allocate(fn->params().data[0]);
                 appendf("mov %s, rdi\n", GetSlotAddr(param_slot).c_str());
             }
-            for(auto &fOp : fn->ops())
+            for(auto &fOp : fn->body().ops())
             {
                 GenerateOp(fOp);
             }
diff --git a/include/ir/block.hpp b/include/ir/block.hpp
new file mode 100644
index 0000000..a4c5619
--- /dev/null
+++ b/include/ir/block.hpp
@@ -0,0 +1,35 @@
+#pragma once
+#include "ir/op.hpp"
+
+namespace IR
+{
+
+using OpView = View<Op*>;
+
+using BlockID = unsigned int;
+
+class Block
+{
+public:
+    Block(BlockID id, OpView&& ops)
+        : m_id(id), m_ops(ops) {}
+public:
+    const OpView& ops() const { return m_ops; }
+public:
+    StringView Format(int indent) const
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb.AppendFormat("b%d:\n", m_id);
+        for (size_t i = 0; i < m_ops.size; ++i)
+        {
+            sb << m_ops.data[i]->Format(indent + 2) << '\n';
+        }
+        return sb.view();
+    }
+private:
+    BlockID m_id;
+    OpView m_ops;
+};
+
+} // namespace IR
diff --git a/include/ir/ir.hpp b/include/ir/ir.hpp
index 9ea3306..60f2ac0 100644
--- a/include/ir/ir.hpp
+++ b/include/ir/ir.hpp
@@ -5,240 +5,29 @@
 #include "ir/slot.hpp"
 #include "ir/allocator.hpp"
 #include "ir/value.hpp"
+#include "ir/ops.hpp"
 
 namespace IR
 {
 
-enum class OpType
-{
-    EXTERN = 0,
-    FN,
-    LOAD_CONST,
-    LOAD,
-    STORE,
-    ADD,
-    CALL,
-    COUNT_OPS,
-};
-
-#define OP_TYPE(x) \
-    OpType GetType() const override { return OpType::x; }
-
-class Op
-{
-public:
-    virtual OpType GetType() const = 0;
-    virtual ~Op() {}
-
-    virtual StringView Format(int indent) const = 0;
-};
-
-using OpView = View<Op*>;
-using OpBuilder = Builder<Op*>;
-
-class Valued
-{
-public:
-    Valued(Value dest)
-        : m_dest(dest) {}
-    ~Valued() = default;
-public:
-    Value result() const { return m_dest; }
-private:
-    Value m_dest;
-};
-
-class ExternOp : public Op
-{
-public:
-    ExternOp(StringView symbol)
-        : m_symbol(symbol) {}
-    ~ExternOp() {}
-
-    OP_TYPE(EXTERN)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << "EXTRN " << m_symbol.c_str();
-        return sb.view();
-    }
-public:
-    const StringView& symbol() const { return m_symbol; }
-private:
-    StringView m_symbol;
-};
-
-class FnOp : public Op
-{
-public:
-    FnOp(StringView name, const CompoundNode* body, const View<StringView>& params);
-    ~FnOp() {}
-
-    OP_TYPE(FN)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << "LABEL " << m_name.c_str() << ':' << '\n';
-        for (size_t i = 0; i < m_ops.size; ++i)
-        {
-            sb << m_ops.data[i]->Format(indent + 2) << '\n';
-        }
-        return sb.view();
-    }
-public:
-    const StringView& name() const { return m_name; }
-    const OpView& ops() const { return m_ops; }
-    const View<StringView>& params() const { return m_params; }
-private:
-    StringView m_name;
-    OpView m_ops;
-    ValueView m_slots;
-    View<StringView> m_params;
-};
-
-class LoadConstOp : public Op, public Valued
-{
-public:
-    LoadConstOp(Value dest, long value)
-        : Valued(dest), m_value(value) {}
-    ~LoadConstOp() {}
-
-    OP_TYPE(LOAD_CONST)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << result().Format() << " = LOAD_CONST " << m_value;
-        return sb.view();
-    }
-public:
-    long value() const { return m_value; }
-private:
-    long m_value;
-};
-
-class LoadOp : public Op, public Valued
-{
-public:
-    LoadOp(Value dest, StringView addr)
-        : Valued(dest), m_addr(addr) {}
-    ~LoadOp() {}
-
-    OP_TYPE(LOAD)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << result().Format() << " = LOAD \"" << m_addr.c_str() << "\"";
-        return sb.view();
-    }
-public:
-    const StringView& addr() const { return m_addr; }
-private:
-    StringView m_addr;
-};
-
-class StoreOp : public Op
-{
-public:
-    StoreOp(StringView addr, Value src)
-        : m_addr(addr), m_src(src) {}
-    ~StoreOp() {}
-
-    OP_TYPE(STORE)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << "STORE \"" << m_addr.c_str() << "\", " << m_src.Format();
-        return sb.view();
-    }
-public:
-    const StringView& addr() const { return m_addr; }
-    Value src() const { return m_src; }
-private:
-    StringView m_addr;
-    Value m_src;
-};
-
-class AddOp : public Op, public Valued
-{
-public:
-    AddOp(Value dest, Value lhs, Value rhs)
-        : Valued(dest), m_lhs(lhs), m_rhs(rhs) {}
-    ~AddOp() {}
-
-    OP_TYPE(ADD)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        sb.AppendIndent(indent);
-        sb << result().Format() << " = ADD " << m_lhs.Format() << ", " << m_rhs.Format();
-        return sb.view();
-    }
-public:
-    Value lhs() const { return m_lhs; }
-    Value rhs() const { return m_rhs; }
-private:
-    Value m_lhs;
-    Value m_rhs;
-};
-
-class CallOp : public Op, public Valued
-{
-public:
-    CallOp(Value dest, StringView callee, ValueView args)
-        : Valued(dest), m_callee(callee), m_args(args) {}
-    ~CallOp() {}
-
-    OP_TYPE(CALL)
-public:
-    StringView Format(int indent) const override
-    {
-        StringBuilder sb;
-        for (size_t i = 0; i < m_args.size; ++i)
-        {
-            sb.AppendIndent(indent);
-            sb << "PARAM " << m_args.data[i].Format() << '\n';
-        }
-        sb.AppendIndent(indent);
-        sb << result().Format() << " = CALL " << m_callee.c_str();
-        return sb.view();
-    }
-public:
-    const StringView& callee() const { return m_callee; }
-    const ValueView& args() const { return m_args; }
-private:
-    StringView m_callee;
-    ValueView m_args;
-};
-
 class IRBuilder
 {
 public:
     IRBuilder(const Node* root)
-        : m_root(root) {}
+        : m_root(root), m_ops(new OpBuilder()) {}
 public:
     // TODO: support other literals
     Value ParseIntLiteral(const IntLiteralNode* literal)
     {
         auto dst = AllocateRegister();
-        m_ops.Push(new LoadConstOp(dst, literal->integer()));
+        m_ops->Push(new LoadConstOp(dst, literal->integer()));
         return dst;
     }
 
     Value ParseVariable(const VariableNode* var)
     {
         // auto dst = AllocateRegister();
-        // m_ops.Push(new LoadOp(dst, var->name()));
+        // m_ops->Push(new LoadOp(dst, var->name()));
         if (m_locals.find(var->name()) == m_locals.end())
         {
             // TODO: throw proper error
@@ -257,7 +46,7 @@ public:
             argRegs.Push(arg);
         }
         auto dst = AllocateRegister();
-        m_ops.Push(new CallOp(dst, fn->name(), argRegs.view()));
+        m_ops->Push(new CallOp(dst, fn->name(), argRegs.view()));
         return dst;
     }
 
@@ -287,7 +76,7 @@ public:
             assert(4 == static_cast<int>(ExpressionNode::Operator::COUNT_OPERATORS) && "some operators may not be handled");
             switch (expr->op())
             {
-            case ExpressionNode::Operator::Plus: m_ops.Push(new AddOp(dst, lhs, rhs)); break;
+            case ExpressionNode::Operator::Plus: m_ops->Push(new AddOp(dst, lhs, rhs)); break;
             default: assert(0 && "TODO: implement other operations"); break;
             }
 
@@ -300,12 +89,13 @@ public:
     void ParseVarDecl(const VarDeclNode* varDecl)
     {
         auto value = ParseExpression(varDecl->value());
-        // m_ops.Push(new StoreOp(varDecl->name(), value));
+        // m_ops->Push(new StoreOp(varDecl->name(), value));
         m_locals.insert(std::make_pair(varDecl->name(), value));
     }
 
-    void ParseBlock(const CompoundNode* compound)
+    Block ParseBlock(const CompoundNode* compound)
     {
+        StartBlock();
         for (auto &statement : *compound)
         {
             switch(statement->GetType())
@@ -314,6 +104,10 @@ public:
             default: ParseExpression(statement); continue;
             }
         }
+        auto ops = EndBlock();
+        auto block = Block(m_block_counter++, std::move(ops->view()));
+        operator delete(ops);
+        return block;
     }
 
     OpView Build()
@@ -324,32 +118,50 @@ public:
         // Externs
         for (auto &extrn : program->externs())
         {
-            m_ops.Push(new ExternOp(extrn->symbol()));
+            m_ops->Push(new ExternOp(extrn->symbol()));
         }
 
         // Functions
         for (auto &fn : program->funcs())
         {
-            m_ops.Push(new FnOp(fn->name(), fn->body(), fn->params()));
+            auto block = ParseBlock(fn->body());
+            m_ops->Push(new FnOp(fn->name(), fn->params(), std::move(block)));
         }
 
-        return OpView(m_ops.data, m_ops.size);
+        return OpView(m_ops->data, m_ops->size);
     }
 public:
-    // TODO: think about safety (copying m_ops.data before giving)
-    OpView ops() const { return OpView(m_ops.data, m_ops.size); }
+    // TODO: think about safety (copying m_ops->data before giving)
+    OpView ops() const { return OpView(m_ops->data, m_ops->size); }
+private:
+    void StartBlock()
+    {
+        m_containers.Push(m_ops);
+        m_ops = new OpBuilder();
+    }
+
+    OpBuilder* EndBlock()
+    {
+        assert(m_containers.size > 0 && "containers stack is empty");
+        auto current = m_ops;
+        m_ops = m_containers.data[m_containers.size - 1];
+        m_containers.size--;
+        return current;
+    }
 private:
     Value AllocateRegister()
     {
         return Value(m_value_counter++);
     }
 private:
-    OpBuilder m_ops;
     const Node* m_root = nullptr;
 
+    OpBuilder* m_ops = nullptr;
     unsigned int m_value_counter = 0;
-
+    unsigned int m_block_counter = 0;
     std::unordered_map<StringView, Value> m_locals;
+
+    Builder<OpBuilder*> m_containers;
 };
 
 } // namespace IR
diff --git a/include/ir/op.hpp b/include/ir/op.hpp
new file mode 100644
index 0000000..fa616d6
--- /dev/null
+++ b/include/ir/op.hpp
@@ -0,0 +1,50 @@
+#pragma once
+#include "prelude/string.hpp"
+#include "ir/value.hpp"
+
+namespace IR
+{
+
+enum class OpType
+{
+    EXTERN = 0,
+    FN,
+    LOAD_CONST,
+    LOAD,
+    STORE,
+    ADD,
+    CALL,
+    COUNT_OPS,
+};
+
+#define OP_TYPE(x) \
+    OpType GetType() const override { return OpType::x; }
+
+class Op
+{
+public:
+    virtual OpType GetType() const = 0;
+    virtual bool Valued() const { return false; };
+    virtual ~Op() {}
+
+    virtual StringView Format(int indent) const = 0;
+};
+
+using OpView = View<Op*>;
+using OpBuilder = Builder<Op*>;
+
+class OpValued : public Op
+{
+public:
+    OpValued(Value dest)
+        : m_dest(dest) {}
+    ~OpValued() = default;
+public:
+    Value result() const { return m_dest; }
+protected:
+    bool Valued() const override { return true; }
+private:
+    Value m_dest;
+};
+
+} // namespace IR
\ No newline at end of file
diff --git a/include/ir/ops.hpp b/include/ir/ops.hpp
new file mode 100644
index 0000000..3136e6c
--- /dev/null
+++ b/include/ir/ops.hpp
@@ -0,0 +1,183 @@
+#pragma once
+#include "prelude/string.hpp"
+#include "parser/nodes.hpp"
+#include "ir/value.hpp"
+#include "ir/op.hpp"
+#include "ir/block.hpp"
+
+namespace IR
+{
+
+class ExternOp : public Op
+{
+public:
+    ExternOp(StringView symbol)
+        : m_symbol(symbol) {}
+    ~ExternOp() {}
+
+    OP_TYPE(EXTERN)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << "EXTRN " << m_symbol.c_str();
+        return sb.view();
+    }
+public:
+    const StringView& symbol() const { return m_symbol; }
+private:
+    StringView m_symbol;
+};
+
+// TODO: Make function return value (i.e. inhreit the OpValued class instead)
+class FnOp : public Op
+{
+public:
+    FnOp(StringView name, const View<StringView>& params, Block&& block)
+        : m_name(name), m_params(params), m_body(block) {}
+    ~FnOp() {}
+
+    OP_TYPE(FN)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << "LABEL " << m_name.c_str() << ':' << '\n';
+        sb << m_body.Format(indent);
+        return sb.view();
+    }
+public:
+    const StringView& name() const { return m_name; }
+    const Block& body() const { return m_body; }
+    const View<StringView>& params() const { return m_params; }
+private:
+    StringView m_name;
+    ValueView m_slots;
+    View<StringView> m_params;
+    Block m_body;
+};
+
+class LoadConstOp : public OpValued
+{
+public:
+    LoadConstOp(Value dest, long value)
+        : OpValued(dest), m_value(value) {}
+    ~LoadConstOp() {}
+
+    OP_TYPE(LOAD_CONST)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << result().Format() << " = LOAD_CONST " << m_value;
+        return sb.view();
+    }
+public:
+    long value() const { return m_value; }
+private:
+    long m_value;
+};
+
+class LoadOp : public OpValued
+{
+public:
+    LoadOp(Value dest, StringView addr)
+        : OpValued(dest), m_addr(addr) {}
+    ~LoadOp() {}
+
+    OP_TYPE(LOAD)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << result().Format() << " = LOAD \"" << m_addr.c_str() << "\"";
+        return sb.view();
+    }
+public:
+    const StringView& addr() const { return m_addr; }
+private:
+    StringView m_addr;
+};
+
+class StoreOp : public Op
+{
+public:
+    StoreOp(StringView addr, Value src)
+        : m_addr(addr), m_src(src) {}
+    ~StoreOp() {}
+
+    OP_TYPE(STORE)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << "STORE \"" << m_addr.c_str() << "\", " << m_src.Format();
+        return sb.view();
+    }
+public:
+    const StringView& addr() const { return m_addr; }
+    Value src() const { return m_src; }
+private:
+    StringView m_addr;
+    Value m_src;
+};
+
+class AddOp : public OpValued
+{
+public:
+    AddOp(Value dest, Value lhs, Value rhs)
+        : OpValued(dest), m_lhs(lhs), m_rhs(rhs) {}
+    ~AddOp() {}
+
+    OP_TYPE(ADD)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        sb.AppendIndent(indent);
+        sb << result().Format() << " = ADD " << m_lhs.Format() << ", " << m_rhs.Format();
+        return sb.view();
+    }
+public:
+    Value lhs() const { return m_lhs; }
+    Value rhs() const { return m_rhs; }
+private:
+    Value m_lhs;
+    Value m_rhs;
+};
+
+class CallOp : public OpValued
+{
+public:
+    CallOp(Value dest, StringView callee, ValueView args)
+        : OpValued(dest), m_callee(callee), m_args(args) {}
+    ~CallOp() {}
+
+    OP_TYPE(CALL)
+public:
+    StringView Format(int indent) const override
+    {
+        StringBuilder sb;
+        for (size_t i = 0; i < m_args.size; ++i)
+        {
+            sb.AppendIndent(indent);
+            sb << "PARAM " << m_args.data[i].Format() << '\n';
+        }
+        sb.AppendIndent(indent);
+        sb << result().Format() << " = CALL " << m_callee.c_str();
+        return sb.view();
+    }
+public:
+    const StringView& callee() const { return m_callee; }
+    const ValueView& args() const { return m_args; }
+private:
+    StringView m_callee;
+    ValueView m_args;
+};
+
+} // namespace IR
diff --git a/include/parser/ast.hpp b/include/parser/ast.hpp
index c9db9b3..d08db77 100644
--- a/include/parser/ast.hpp
+++ b/include/parser/ast.hpp
@@ -3,222 +3,7 @@
 #include <cassert>
 #include <vector>
 #include "parser/lexer.hpp"
-
-enum class NodeType
-{
-    Expression = 0,
-    // TODO: abstract "Literal" node type
-    IntLiteral,
-    Extern,
-    FnDecl,
-    FnCall,
-    Variable,
-    VarDecl,
-    Compound,
-    Program,
-    COUNT_NODES,
-};
-
-#define NODE_TYPE(x) \
-    NodeType GetType() const override { return NodeType::x; }
-
-class Node
-{
-public:
-    virtual NodeType GetType() const = 0;
-    virtual ~Node() {}
-}; 
-
-class ExpressionNode : public Node
-{
-public:
-    enum class Operator
-    {
-        Plus = 0,
-        Minus,
-        Divide,
-        Multiply,
-        COUNT_OPERATORS,
-    };
-public:
-    ExpressionNode(Node* left, Node* right, Operator op)
-        : m_left(left), m_right(right), m_op(op) {}
-    ~ExpressionNode() override {
-        delete m_left;
-        delete m_right;
-    }
-
-    NODE_TYPE(Expression)
-public:
-    Node* left() const { return m_left; }
-    Node* right() const { return m_right; }
-    Operator op() const { return m_op; }
-private:
-    Node* m_left;
-    Node* m_right;
-    Operator m_op;
-};
-
-// TODO: Maybe just LiteralNode with double or int literals support
-class IntLiteralNode : public Node
-{
-public:
-    IntLiteralNode(long value)
-        : m_int_value(value) {}
-    ~IntLiteralNode() override {}
-
-    NODE_TYPE(IntLiteral)
-public:
-    long integer() const { return m_int_value; }
-private:
-    long m_int_value;
-};
-
-class ExternNode : public Node
-{
-public:
-    // TODO: support multiple extern symbols
-    ExternNode(StringView symbol)
-        : m_symbol(symbol) {}
-    ~ExternNode() override = default;
-
-    NODE_TYPE(Extern)
-public:
-    const StringView& symbol() const { return m_symbol; }
-private:
-    StringView m_symbol;
-};
-
-class CompoundNode : public Node
-{
-public:
-    CompoundNode() = default;
-
-    NODE_TYPE(Compound)
-
-    // --- Iteration ---
-    auto begin() { return m_nodes.begin(); }
-    auto end()   { return m_nodes.end();   }
-    auto begin() const { return m_nodes.begin(); }
-    auto end()   const { return m_nodes.end();   }
-
-    // --- Access by index ---
-    Node* operator[](size_t i) { return m_nodes[i]; }
-    const Node* operator[](size_t i) const { return m_nodes[i]; }
-
-    Node* at(size_t i) { return m_nodes.at(i); }
-    const Node* at(size_t i) const { return m_nodes.at(i); }
-
-    // --- Modifiers ---
-    void addNode(Node* n) { m_nodes.push_back(n); }
-    void removeNode(size_t idx) { m_nodes.erase(m_nodes.begin() + idx); }
-
-    // If you want full expose for iteration but not modification
-    const std::vector<Node*>& nodes() const { return m_nodes; }
-
-    size_t size() const { return m_nodes.size(); }
-    bool empty() const { return m_nodes.empty(); }
-private:
-    std::vector<Node*> m_nodes;
-};
-
-class FnDeclNode : public Node
-{
-public:
-    // TODO: support parameters
-    FnDeclNode(const StringView& name, CompoundNode* body, View<StringView> params)
-        : m_name(name), m_body(body), m_params(params) {}
-    ~FnDeclNode() override {
-        delete m_body;
-    }
-
-    NODE_TYPE(FnDecl)
-public:
-    const StringView& name() const { return m_name; }
-    const CompoundNode* body() const { return m_body; }
-    const View<StringView>& params() const { return m_params; }
-private:
-    StringView m_name;
-    CompoundNode* m_body;
-    View<StringView> m_params;
-};
-
-class FnCallNode : public Node
-{
-public:
-    // TODO: support multiple arguments
-    FnCallNode(const StringView& name, Node* arg)
-        : m_name(name), m_arg(arg) {}
-    ~FnCallNode() override {
-        delete m_arg;
-    }
-
-    NODE_TYPE(FnCall)
-public:
-    const StringView& name() const { return m_name; }
-    // TODO: support multiple args
-    const Node* arg() const { return m_arg; }
-private:
-    StringView m_name;
-    Node* m_arg;
-};
-
-class VariableNode : public Node
-{
-public:
-    VariableNode(const StringView& name)
-        : m_name(name) {}
-    ~VariableNode() override = default;
-
-    NODE_TYPE(Variable)
-public:
-    const StringView& name() const { return m_name; }
-private:
-    StringView m_name;
-};
-
-class VarDeclNode : public Node
-{
-public:
-    VarDeclNode(const StringView& name, Node* value)
-        : m_name(name), m_value(value) {}
-    ~VarDeclNode() override {
-        delete m_value;
-    }
-
-    NODE_TYPE(VarDecl)
-public:
-    const StringView& name() const { return m_name; }
-    const Node* value() const { return m_value; }
-private:
-    StringView m_name;
-    Node* m_value;
-};
-
-class ProgramNode : public Node
-{
-public:
-    ProgramNode() = default;
-
-    NODE_TYPE(Program)
-public:
-    void PushFunction(FnDeclNode* fn)
-    {
-        m_funcs.push_back(fn);
-    }
-
-    void PushExtern(ExternNode* extrn)
-    {
-        m_externs.push_back(extrn);
-    }
-public:
-    const std::vector<ExternNode*> externs() const { return m_externs; }
-    const std::vector<FnDeclNode*> funcs() const { return m_funcs; }
-private:
-    std::vector<FnDeclNode*> m_funcs;
-    std::vector<ExternNode*> m_externs;
-};
-
+#include "parser/nodes.hpp"
 
 class AstParser
 {
diff --git a/include/parser/nodes.hpp b/include/parser/nodes.hpp
new file mode 100644
index 0000000..88839f9
--- /dev/null
+++ b/include/parser/nodes.hpp
@@ -0,0 +1,217 @@
+#pragma once
+#include "prelude/string.hpp"
+
+enum class NodeType
+{
+    Expression = 0,
+    // TODO: abstract "Literal" node type
+    IntLiteral,
+    Extern,
+    FnDecl,
+    FnCall,
+    Variable,
+    VarDecl,
+    Compound,
+    Program,
+    COUNT_NODES,
+};
+
+#define NODE_TYPE(x) \
+    NodeType GetType() const override { return NodeType::x; }
+
+class Node
+{
+public:
+    virtual NodeType GetType() const = 0;
+    virtual ~Node() {}
+}; 
+
+class ExpressionNode : public Node
+{
+public:
+    enum class Operator
+    {
+        Plus = 0,
+        Minus,
+        Divide,
+        Multiply,
+        COUNT_OPERATORS,
+    };
+public:
+    ExpressionNode(Node* left, Node* right, Operator op)
+        : m_left(left), m_right(right), m_op(op) {}
+    ~ExpressionNode() override {
+        delete m_left;
+        delete m_right;
+    }
+
+    NODE_TYPE(Expression)
+public:
+    Node* left() const { return m_left; }
+    Node* right() const { return m_right; }
+    Operator op() const { return m_op; }
+private:
+    Node* m_left;
+    Node* m_right;
+    Operator m_op;
+};
+
+// TODO: Maybe just LiteralNode with double or int literals support
+class IntLiteralNode : public Node
+{
+public:
+    IntLiteralNode(long value)
+        : m_int_value(value) {}
+    ~IntLiteralNode() override {}
+
+    NODE_TYPE(IntLiteral)
+public:
+    long integer() const { return m_int_value; }
+private:
+    long m_int_value;
+};
+
+class ExternNode : public Node
+{
+public:
+    // TODO: support multiple extern symbols
+    ExternNode(StringView symbol)
+        : m_symbol(symbol) {}
+    ~ExternNode() override = default;
+
+    NODE_TYPE(Extern)
+public:
+    const StringView& symbol() const { return m_symbol; }
+private:
+    StringView m_symbol;
+};
+
+class CompoundNode : public Node
+{
+public:
+    CompoundNode() = default;
+
+    NODE_TYPE(Compound)
+
+    // --- Iteration ---
+    auto begin() { return m_nodes.begin(); }
+    auto end()   { return m_nodes.end();   }
+    auto begin() const { return m_nodes.begin(); }
+    auto end()   const { return m_nodes.end();   }
+
+    // --- Access by index ---
+    Node* operator[](size_t i) { return m_nodes[i]; }
+    const Node* operator[](size_t i) const { return m_nodes[i]; }
+
+    Node* at(size_t i) { return m_nodes.at(i); }
+    const Node* at(size_t i) const { return m_nodes.at(i); }
+
+    // --- Modifiers ---
+    void addNode(Node* n) { m_nodes.push_back(n); }
+    void removeNode(size_t idx) { m_nodes.erase(m_nodes.begin() + idx); }
+
+    // If you want full expose for iteration but not modification
+    const std::vector<Node*>& nodes() const { return m_nodes; }
+
+    size_t size() const { return m_nodes.size(); }
+    bool empty() const { return m_nodes.empty(); }
+private:
+    std::vector<Node*> m_nodes;
+};
+
+class FnDeclNode : public Node
+{
+public:
+    // TODO: support parameters
+    FnDeclNode(const StringView& name, CompoundNode* body, View<StringView> params)
+        : m_name(name), m_body(body), m_params(params) {}
+    ~FnDeclNode() override {
+        delete m_body;
+    }
+
+    NODE_TYPE(FnDecl)
+public:
+    const StringView& name() const { return m_name; }
+    const CompoundNode* body() const { return m_body; }
+    const View<StringView>& params() const { return m_params; }
+private:
+    StringView m_name;
+    CompoundNode* m_body;
+    View<StringView> m_params;
+};
+
+class FnCallNode : public Node
+{
+public:
+    // TODO: support multiple arguments
+    FnCallNode(const StringView& name, Node* arg)
+        : m_name(name), m_arg(arg) {}
+    ~FnCallNode() override {
+        delete m_arg;
+    }
+
+    NODE_TYPE(FnCall)
+public:
+    const StringView& name() const { return m_name; }
+    // TODO: support multiple args
+    const Node* arg() const { return m_arg; }
+private:
+    StringView m_name;
+    Node* m_arg;
+};
+
+class VariableNode : public Node
+{
+public:
+    VariableNode(const StringView& name)
+        : m_name(name) {}
+    ~VariableNode() override = default;
+
+    NODE_TYPE(Variable)
+public:
+    const StringView& name() const { return m_name; }
+private:
+    StringView m_name;
+};
+
+class VarDeclNode : public Node
+{
+public:
+    VarDeclNode(const StringView& name, Node* value)
+        : m_name(name), m_value(value) {}
+    ~VarDeclNode() override {
+        delete m_value;
+    }
+
+    NODE_TYPE(VarDecl)
+public:
+    const StringView& name() const { return m_name; }
+    const Node* value() const { return m_value; }
+private:
+    StringView m_name;
+    Node* m_value;
+};
+
+class ProgramNode : public Node
+{
+public:
+    ProgramNode() = default;
+
+    NODE_TYPE(Program)
+public:
+    void PushFunction(FnDeclNode* fn)
+    {
+        m_funcs.push_back(fn);
+    }
+
+    void PushExtern(ExternNode* extrn)
+    {
+        m_externs.push_back(extrn);
+    }
+public:
+    const std::vector<ExternNode*> externs() const { return m_externs; }
+    const std::vector<FnDeclNode*> funcs() const { return m_funcs; }
+private:
+    std::vector<FnDeclNode*> m_funcs;
+    std::vector<ExternNode*> m_externs;
+};
\ No newline at end of file
diff --git a/src/ir.cpp b/src/ir.cpp
deleted file mode 100644
index c237fb8..0000000
--- a/src/ir.cpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#include "ir/ir.hpp"
-
-IR::FnOp::FnOp(StringView name, const CompoundNode* body, const View<StringView>& params)
-    : m_name(name), m_params(params)
-{
-    IRBuilder ir(body);        // Now IRBuilder is complete → OK
-    ir.ParseBlock(body);
-    m_ops = std::move(ir.ops());
-}
\ No newline at end of file