From aa0a379b37889caad022ec12fba76990b2e2e2d9 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Mon, 17 Jan 2022 18:38:05 -0500
Subject: [PATCH] Add JSON::isDictionary and JSON::isArray

---
 ChangeLog            |  4 ++++
 include/qpdf/JSON.hh |  6 ++++++
 libqpdf/JSON.cc      | 14 ++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 8fa0d315..696915ad 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,10 @@
 	to QPDFObjectHandle with corresponding functions added to the C
 	API. Thanks to m-holger for the contribution.
 
+2022-01-17  Jay Berkenbilt  <ejb@ql.org>
+
+	* Add isDictionary and isArray to JSON
+
 2022-01-11  Jay Berkenbilt  <ejb@ql.org>
 
 	* Bug fix: add missing characters from PDF doc encoding.
diff --git a/include/qpdf/JSON.hh b/include/qpdf/JSON.hh
index 3618d1e7..11fe2c7b 100644
--- a/include/qpdf/JSON.hh
+++ b/include/qpdf/JSON.hh
@@ -69,6 +69,12 @@ class JSON
     QPDF_DLL
     static JSON makeNull();
 
+    QPDF_DLL
+    bool isArray() const;
+
+    QPDF_DLL
+    bool isDictionary() const;
+
     // Check this JSON object against a "schema". This is not a schema
     // according to any standard. It's just a template of what the
     // JSON is supposed to contain. The checking does the following:
diff --git a/libqpdf/JSON.cc b/libqpdf/JSON.cc
index f75935aa..c656bb14 100644
--- a/libqpdf/JSON.cc
+++ b/libqpdf/JSON.cc
@@ -293,6 +293,20 @@ JSON::makeNull()
     return JSON(new JSON_null());
 }
 
+bool
+JSON::isArray() const
+{
+    return nullptr != dynamic_cast<JSON_array const*>(
+        this->m->value.getPointer());
+}
+
+bool
+JSON::isDictionary() const
+{
+    return nullptr != dynamic_cast<JSON_dictionary const*>(
+        this->m->value.getPointer());
+}
+
 bool
 JSON::checkSchema(JSON schema, std::list<std::string>& errors)
 {