From f0bb0d2262360fff08a6f9a7a46e033cdecd03e9 Mon Sep 17 00:00:00 2001
From: Ray Speth <speth@mit.edu>
Date: Mon, 17 Dec 2018 23:29:33 -0500
Subject: [PATCH] Make AnyMap iterable

---
 include/cantera/base/AnyMap.h    | 14 ++++++++++++++
 src/base/AnyMap.cpp              |  8 ++++++++
 test/general/test_containers.cpp | 18 ++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/include/cantera/base/AnyMap.h b/include/cantera/base/AnyMap.h
index 7cf2fbe4f..81a6ee91c 100644
--- a/include/cantera/base/AnyMap.h
+++ b/include/cantera/base/AnyMap.h
@@ -229,6 +229,16 @@ public:
     const std::string& getString(const std::string& key,
                                  const std::string& default_) const;
 
+    // Define begin() and end() to allow use with range-based for loops
+    using const_iterator = std::unordered_map<std::string, AnyValue>::const_iterator;
+    const_iterator begin() const {
+        return m_data.begin();
+    }
+
+    const_iterator end() const {
+        return m_data.end();
+    }
+
 private:
     template <class T>
     const T& get(const std::string& key, const T& default_,
@@ -238,6 +248,10 @@ private:
     friend class AnyValue;
 };
 
+// Define begin() and end() to allow use with range-based for loops
+AnyMap::const_iterator begin(const AnyValue& v);
+AnyMap::const_iterator end(const AnyValue& v);
+
 }
 
 #ifndef CANTERA_API_NO_BOOST
diff --git a/src/base/AnyMap.cpp b/src/base/AnyMap.cpp
index 45b13319d..def12bacd 100644
--- a/src/base/AnyMap.cpp
+++ b/src/base/AnyMap.cpp
@@ -606,4 +606,12 @@ AnyMap AnyMap::fromYamlFile(const std::string& name) {
     return node.as<AnyMap>();
 }
 
+AnyMap::const_iterator begin(const AnyValue& v) {
+    return v.as<AnyMap>().begin();
+}
+
+AnyMap::const_iterator end(const AnyValue& v) {
+    return v.as<AnyMap>().end();
+}
+
 }
diff --git a/test/general/test_containers.cpp b/test/general/test_containers.cpp
index 134bc9ade..02ce1eab5 100644
--- a/test/general/test_containers.cpp
+++ b/test/general/test_containers.cpp
@@ -150,6 +150,24 @@ TEST(AnyMap, conversion_to_anyvalue)
     EXPECT_EQ(n.at("strings").asVector<AnyValue>()[0].asString(), "foo");
 }
 
+TEST(AnyMap, iterators)
+{
+    AnyMap m = AnyMap::fromYamlString(
+        "{a: 1, b: two, c: 3.01, d: {foo: 1, bar: 2}}");
+    std::vector<std::string> keys;
+    for (const auto& item : m) {
+        keys.push_back(item.first);
+    }
+    EXPECT_EQ(keys.size(), (size_t) 4);
+    EXPECT_TRUE(std::find(keys.begin(), keys.end(), "c") != keys.end());
+    keys.clear();
+
+    for (const auto& item : m.at("d")) {
+        keys.push_back(item.first);
+    }
+    EXPECT_EQ(keys.size(), (size_t) 2);
+    EXPECT_TRUE(std::find(keys.begin(), keys.end(), "bar") != keys.end());
+}
 
 TEST(AnyMap, loadYaml)
 {