remove unsafe code in Belt.Stack

Author: bobzhang

jscomp/others/belt_MutableStack.ml

@@ -89,15 +89,17 @@ let forEachU s f =
   iterAux s.root f 
 
 let forEach s f = forEachU s (fun [@bs] x -> f x)
-    
-let dynamicPopIterU s f =    
-  let cursor = ref s.root in 
-  while cursor.contents != None do 
-    let v = Belt_Option.getUnsafe cursor.contents in 
-    s.root <- v.tail;
-    f v.head [@bs];
-    cursor .contents<- s.root (* using root, [f] may change it*)
-  done
+
+
+let rec dynamicPopIterU s  f = 
+  match s.root with 
+  | Some {tail; head }-> 
+    s.root <- tail;
+    f head [@bs] ;
+    dynamicPopIterU s  f (* using root, [f] may change it*)
+ | None -> ()   
+
+
 
 let dynamicPopIter s f = dynamicPopIterU s (fun [@bs] x -> f x)
 

lib/es6/belt_MutableStack.js

@@ -108,14 +108,16 @@ function forEach(s, f) {
 }
 
 function dynamicPopIterU(s, f) {
-  var cursor = s.root;
-  while(cursor !== undefined) {
-    var v = cursor;
-    s.root = v.tail;
-    f(v.head);
-    cursor = s.root;
+  while(true) {
+    var match = s.root;
+    if (match === undefined) {
+      return ;
+    }
+    var match$1 = match;
+    s.root = match$1.tail;
+    f(match$1.head);
+    continue ;
   };
-  
 }
 
 function dynamicPopIter(s, f) {

lib/js/belt_MutableStack.js

@@ -108,14 +108,16 @@ function forEach(s, f) {
 }
 
 function dynamicPopIterU(s, f) {
-  var cursor = s.root;
-  while(cursor !== undefined) {
-    var v = cursor;
-    s.root = v.tail;
-    f(v.head);
-    cursor = s.root;
+  while(true) {
+    var match = s.root;
+    if (match === undefined) {
+      return ;
+    }
+    var match$1 = match;
+    s.root = match$1.tail;
+    f(match$1.head);
+    continue ;
   };
-  
 }
 
 function dynamicPopIter(s, f) {