Move parsers out of Parser.parse

parser.ml

@@ -92,10 +92,28 @@ let (@>) f g seq =
   let a, seq = f seq in
   g a seq
 
-(* parse tokens *)
-let parse ts =
+(* expr := "level" level_inner
+ *       | value binop_right
+*)
+let rec expr seq =
+  seq |> either
+    (ident "level" @> level_inner)
+    (value @> binop ~-1)
+
+(* level_inner := "get" | "set" [op] *)
+and level_inner _ seq =
+  let id, seq = idents (S.of_list ["get"; "set"]) seq in
+  let op, seq = operator seq in
+  if id = "get" then
+    Get_binop_pre op, seq
+  else if id = "set" then
+    let v, seq = value seq in
+    Set_binop_pre (op, v), seq
+  else
+    failwith "Parser.level"
+
 (* value := int | ( expr ) *)
-  let rec value seq =
+and value seq =
   match seq () with
   | Seq.Nil -> raise End_of_tokens
   | Seq.Cons (x, seq) -> begin match x with
@@ -115,7 +133,7 @@ let parse ts =
         let op = token_to_op op in
         let o = precedence_of op in
         (* op has to be calculated first *)
-          if o > pre || op_is_right_to_left op && o = pre then
+        if o > pre || (op_is_right_to_left op && o = pre) then
           let v, seq = value seq in
           let right, seq = binop o v seq in
           binop pre (Ast.binop left op right) seq
@@ -125,26 +143,8 @@ let parse ts =
       | _ -> unexpected_token x
     end
 
-  (* level_inner := "get" | "set" [op] *)
-  and level_inner _ seq =
-    let id, seq = idents (S.of_list ["get"; "set"]) seq in
-    let op, seq = operator seq in
-    if id = "get" then
-      Get_binop_pre op, seq
-    else if id = "set" then
-      let v, seq = value seq in
-      Set_binop_pre (op, v), seq
-    else
-      failwith "Parser.level"
-
-  (* expr := "level" level_inner
-   *       | value binop_right
-   *)
-  and expr seq =
-    seq |> either
-      (ident "level" @> level_inner)
-      (value @> binop ~-1)
-  in
+(* parse tokens *)
+let parse ts =
   let ast, rest = expr ts in
   if rest () <> Seq.Nil then failwith "Parser.parse";
   ast