From 1507c6c40f944b477e7533fef93e7e4826b7a3b2 Mon Sep 17 00:00:00 2001
From: Yiyun Liu <liuyiyun@seas.upenn.edu>
Date: Sat, 24 May 2025 13:21:15 -0400
Subject: [PATCH] Add file for AST

---
 ast.rkt | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 ast.rkt

diff --git a/ast.rkt b/ast.rkt
new file mode 100644
index 0000000..a0b4aa0
--- /dev/null
+++ b/ast.rkt
@@ -0,0 +1,19 @@
+#lang typed/racket
+
+(define-type ConId Integer)
+(define-type Arity Integer)
+(define-type Let (∪ 'let 'letrec))
+(define-type Name Symbol)
+
+
+(define-type (Bind A) (List A (Expr A)))
+(define-type (Alt A) (List 'branch ConId (Listof A) (Expr A)))
+
+(define-type (Expr A)
+  (∪ Name
+     Integer
+     (List 'pack ConId Arity)
+     (List (Expr A) (Expr A))
+     (List Let (Pair (Bind A) (Listof (Bind A))) (Expr A))
+     (List 'case (Expr A) (Pair (Alt A) (Listof (Alt A))))
+     (List 'λ (Pair Name (Listof Name)) (Expr A))))