add int into value type in IR

ast.ml

@@ -7,5 +7,6 @@ module Syntax = struct
 end
 
 module IR = struct
-  type expr = Int of int
+  type value = Int of int
+  type expr = Val of value
 end

compiler.ml

@@ -2,9 +2,12 @@ open Ast.IR
 open Mips
 module Env = Map.Make (String)
 
-let rec compile_expr e =
-  match e with
+let compile_value = function
   | Int n -> [ Li (V0, n) ]
 ;;
 
+let compile_expr = function
+  | Val v -> compile_value v
+;;
+
 let compile ir = { text = Baselib.builtins @ compile_expr ir; data = [] }

semantics.ml

@@ -6,7 +6,7 @@ exception Error of string * Lexing.position
 
 let rec analyze_expr expr env =
   match expr with
-  | Syntax.Int n -> Int n.value
+  | Syntax.Int n -> Val (Int n.value)
 ;;
 
 let analyze parsed = analyze_expr parsed Baselib._types_