From a1d7289859b3039d65a71da7b72e804cbe28a5f6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jaakko=20Kera=CC=88nen?= <jaakko.keranen@iki.fi>
Date: Mon, 4 Aug 2014 19:19:36 +0300
Subject: [PATCH] Refactor|libcore|Record: Trying out C++11 for listing
 subrecords

One can use a lambda function to filter out the list of subrecords.
---
 doomsday/libcore/include/de/data/record.h | 11 +++++++++
 doomsday/libcore/src/data/record.cpp      | 28 ++++++++++++++---------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/doomsday/libcore/include/de/data/record.h b/doomsday/libcore/include/de/data/record.h
index 58ee0ac329..8c3a031661 100644
--- a/doomsday/libcore/include/de/data/record.h
+++ b/doomsday/libcore/include/de/data/record.h
@@ -31,6 +31,7 @@
 #include <QMap>
 #include <QList>
 #include <QRegExp>
+#include <functional>
 
 namespace de {
 
@@ -388,6 +389,16 @@ class DENG2_PUBLIC Record
      */
     Subrecords subrecords() const;
 
+    /**
+     * Collects a map of all subrecords that fulfill a given predicate.
+     *
+     * @param filter  Inclusion predicate: returns @c true, if the subrecord is to be
+     *                included in the collection.
+     *
+     * @return Map of subrecords.
+     */
+    Subrecords subrecords(std::function<bool (Record const &)> filter) const;
+
     /**
      * Creates a text representation of the record. Each variable name is
      * prefixed with @a prefix.
diff --git a/doomsday/libcore/src/data/record.cpp b/doomsday/libcore/src/data/record.cpp
index d257fecdaa..c0dded59ff 100644
--- a/doomsday/libcore/src/data/record.cpp
+++ b/doomsday/libcore/src/data/record.cpp
@@ -33,6 +33,7 @@
 #include "de/String"
 
 #include <QTextStream>
+#include <functional>
 
 namespace de {
 
@@ -129,21 +130,21 @@ DENG2_PIMPL(Record)
         return value && value->record() && value->hasOwnership();
     }
 
-    /*
-    bool isOwnedSubrecord(Variable const &var) const
-    {
-        RecordValue const *value = var.value().maybeAs<RecordValue>();
-        return value && value->record() && value->hasOwnership();
-    }*/
-
-    Record::Subrecords listSubrecords() const
+    Record::Subrecords listSubrecords(std::function<bool (Record const &)> filter) const
     {
         Subrecords subs;
         DENG2_FOR_EACH_CONST(Members, i, members)
         {
-            if(isSubrecord(*i.value()))
+            Variable const &member = *i.value();
+            if(isSubrecord(member))
             {
-                subs.insert(i.key(), i.value()->value().as<RecordValue>().record());
+                Record *rec = member.value().as<RecordValue>().record();
+                DENG2_ASSERT(rec != 0); // subrecords are owned, so cannot have been deleted
+
+                // Must pass the filter.
+                if(!filter(*rec)) continue;
+
+                subs.insert(i.key(), rec);
             }
         }
         return subs;
@@ -552,7 +553,12 @@ Record::Members const &Record::members() const
 
 Record::Subrecords Record::subrecords() const
 {
-    return d->listSubrecords();
+    return d->listSubrecords([] (Record const &) { return true; /* unfiltered */ });
+}
+
+Record::Subrecords Record::subrecords(std::function<bool (Record const &)> filter) const
+{
+    return d->listSubrecords([&] (Record const &rec) { return filter(rec); });
 }
 
 String Record::asText(String const &prefix, List *lines) const