feat: initial commit

include/ast.hpp

@@ -0,0 +1,39 @@
+#ifndef AST_HPP
+#define AST_HPP
+
+#include <memory>
+#include <string>
+
+// ast stuff lul
+struct Expr {
+  virtual ~Expr() = default;
+};
+
+// represents a simple symbol like "x" or even "thisIsACoolFunctionTrustme100"
+// (ikik the true lambda calculus professionals would now scream at me and say
+// "lambda calculus has only one letter variables!", to which id say ¯\_(ツ)_/¯
+struct Variable : Expr {
+    std::string name;
+
+    Variable(std::string n) : name(std::move(n)) {}
+};
+
+// represents a function itself like \ x . x
+struct Abstraction : Expr {
+    std::string param;
+    std::unique_ptr<Expr> body;
+
+    Abstraction(std::string p, std::unique_ptr<Expr> b) : param(std::move(p)), body(std::move(b)) {}
+};
+
+// wouldnt be turing complete if we couldnt apply to these functions innit
+// (\ x . x) a would be such an application
+// note that parenthesis are your savior because (\ x y . x) (\ x . x) b and
+// (\ x y . x) ((\ x . x) b ) are not the same thing
+struct Application : Expr {
+    std::unique_ptr<Expr> left, right;
+
+    Application(std::unique_ptr<Expr> l, std::unique_ptr<Expr> r) : left(std::move(l)), right(std::move(r)) {}
+};
+
+#endif // AST_HPP