Add automatic rewind for at_pointer (#1624)

include/simdjson/generic/ondemand/array.h

@@ -54,7 +54,7 @@ public:
    *   auto doc = parser.iterate(json);
    *   doc.at_pointer("/0/foo/a/1") == 20
    *
-   * Note that at_pointer() does not automatically rewind between each call (call rewind() to reset).
+   * Note that at_pointer() automatically calls rewind between each call.
    * Also note that at_pointer() relies on find_field() which implies that we do not unescape keys when matching.
    * @return The value associated with the given JSON pointer, or:
    *         - NO_SUCH_FIELD if a field does not exist in an object

include/simdjson/generic/ondemand/document-inl.h

@@ -135,6 +135,7 @@ simdjson_really_inline simdjson_result<std::string_view> document::raw_json_toke
 }
 
 simdjson_really_inline simdjson_result<value> document::at_pointer(std::string_view json_pointer) noexcept {
+  rewind(); // Rewind the document each time at_pointer is called
   if (json_pointer.empty()) {
     return this->resume_value();
   }

include/simdjson/generic/ondemand/document.h

@@ -335,7 +335,7 @@ public:
    *   auto doc = parser.iterate(json);
    *   doc.at_pointer("//a/1") == 20
    *
-   * Note that at_pointer() does not automatically rewind between each call (call rewind() to reset).
+   * Note that at_pointer() automatically calls rewind between each call.
    * Also note that at_pointer() relies on find_field() which implies that we do not unescape keys when matching
    *
    * @return The value associated with the given JSON pointer, or:

include/simdjson/generic/ondemand/object.h

@@ -91,7 +91,7 @@ public:
    *   auto doc = parser.iterate(json);
    *   doc.at_pointer("//a/1") == 20
    *
-   * Note that at_pointer() does not automatically rewind between each call (call rewind() to reset).
+   * Note that at_pointer() automatically calls rewind between each call.
    * Also note that at_pointer() relies on find_field() which implies that we do not unescape keys when matching.
    *
    * @return The value associated with the given JSON pointer, or:

include/simdjson/generic/ondemand/value.h

@@ -330,7 +330,7 @@ public:
    *   auto doc = parser.iterate(json);
    *   doc.at_pointer("//a/1") == 20
    *
-   * Note that at_pointer() does not automatically rewind between each call (call rewind() to reset).
+   * Note that at_pointer() automatically calls rewind between each call.
    * Also note that at_pointer() relies on find_field() which implies that we do not unescape keys when matching
    *
    * @return The value associated with the given JSON pointer, or:

tests/ondemand/ondemand_json_pointer_tests.cpp

@@ -117,7 +117,6 @@ namespace json_pointer_tests {
             std::string json_pointer = "/" + std::to_string(i) + "/tire_pressure/1";
             ASSERT_SUCCESS(cars.at_pointer(json_pointer).get(x));
             measured.push_back(x);
-            cars.rewind();
         }
 
         std::vector<double> expected = {39.9, 31, 30};