feat: introduced blocks and better project structure

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