Update hw4 to a newer version.

Signed-off-by: jmug <u.g.a.mariano@gmail.com>

hw4/bin/ast.ml

@@ -0,0 +1,99 @@
+(* The type declarations in this file correspond to productions in the Oat
+ * grammar provided in the Oat v.1 Language Specification. *)
+
+module Range = Util.Range
+
+(* The `node` type represents a node in an abstract syntax tree. 
+ * The `elt` is the AST element, the `loc` contains the line number
+ * info of the corresponding concrete syntax element. The parser uses
+ * the `loc` to give line numbers with error messages, and you can do 
+ * so too in the compiler if you like!
+ *)
+type 'a node = { elt : 'a; loc : Range.t }
+
+(** val no_loc : 'a1 -> 'a1 node **)
+
+(* This function might be useful if some of your helper functions 
+ * have to return a `node` type.
+ *)
+let no_loc x =
+  { elt = x; loc = Range.norange }
+
+type id = string
+
+(* Oat types *)
+type ty =
+| TBool
+| TInt
+| TRef of rty
+and rty =
+| RString
+| RArray of ty
+| RFun of ty list * ret_ty
+and ret_ty =
+| RetVoid
+| RetVal of ty
+
+type unop =
+| Neg
+| Lognot
+| Bitnot
+
+type binop =
+| Add
+| Sub
+| Mul
+| Eq
+| Neq
+| Lt
+| Lte
+| Gt
+| Gte
+| And
+| Or
+| IAnd
+| IOr
+| Shl
+| Shr
+| Sar
+
+(* Oat expressions *)
+type exp =
+| CNull of rty
+| CBool of bool
+| CInt of int64
+| CStr of string
+| CArr of ty * exp node list
+| NewArr of ty * exp node
+| Id of id
+| Index of exp node * exp node
+| Call of exp node * exp node list
+| Bop of binop * exp node * exp node
+| Uop of unop * exp node
+
+type cfield = id * exp node
+
+type vdecl = id * exp node
+
+type stmt =
+| Assn of exp node * exp node
+| Decl of vdecl
+| Ret of exp node option
+| SCall of exp node * exp node list
+| If of exp node * stmt node list * stmt node list
+| For of vdecl list * exp node option * stmt node option * stmt node list
+| While of exp node * stmt node list
+
+type block = stmt node list
+
+type gdecl = { name : id; init : exp node }
+
+type fdecl = { frtyp : ret_ty; fname : id; args : (ty * id) list; body : block }
+
+type field = { fieldName : id; ftyp : ty }
+
+type decl =
+| Gvdecl of gdecl node
+| Gfdecl of fdecl node
+
+type prog = decl list