Add datatypes.

1 files changed, 9 insertions, 0 deletions

diff --git a/syntax.sml b/syntax.sml
index fbb4dfd..767851d 100644
--- a/syntax.sml
+++ b/syntax.sml
@@ -12,6 +12,7 @@ struct
   | PVar of string
   | PInt of int
   | PTuple of pat list
+  | PCon of string * pat
 
   datatype expr =
     EIdent of string list
@@ -31,6 +32,7 @@ struct
   and dec =
     DVal of pat * expr
   | DValRec of pat * expr
+  | DDatatype of string * (string * etype option) list
 
   (* Lambda language *)
   type var = int
@@ -101,6 +103,11 @@ struct
 
   fun quote (s : string) : string = "\"" ^ String.toString s ^ "\""
 
+  fun optionToString (show : 'a -> string) (x : 'a option) =
+    case x of
+      NONE => "NONE"
+    | SOME x => "SOME " ^ show x
+
   fun etypeToString (x : etype) : string =
     case x of
       Tyvar s => "Tyvar " ^ quote s
@@ -114,6 +121,7 @@ struct
     | PVar v => "PVar " ^ quote v
     | PInt i => "PInt " ^ Int.toString i
     | PTuple pats => "PTuple " ^ listToString patToString pats
+    | PCon (con, v) => "PCon " ^ "(" ^ quote con ^ ", " ^ patToString v ^ ")"
 
   fun exprToStringI (indent : string) (x : expr) : string =
     let val self = exprToStringI indent
@@ -137,6 +145,7 @@ struct
     case x of
       DVal (p, e) => "DVal (" ^ patToString p ^ ", " ^ exprToStringI indent e ^ ")"
     | DValRec (p, e) => "DValRec (" ^ patToString p ^ ", " ^ exprToStringI indent e ^ ")"
+    | DDatatype (name, arms) => "DDatatype (" ^ quote name ^ ", " ^ listToString (fn (con, v) => "(" ^ quote con ^ ", " ^ optionToString etypeToString v ^ ")") arms ^ ")"
 
   val exprToString : expr -> string = exprToStringI ""