From 97e717df1bc69442364523600937df2afd6c6228 Mon Sep 17 00:00:00 2001
From: Ferdinand Majerech <kiithsacmp@gmail.com>
Date: Mon, 4 Aug 2014 02:14:01 +0200
Subject: [PATCH] Loader creates Constructor/Resolver lazily to avoid garbage
 when user-provided

---
 source/dyaml/loader.d | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/source/dyaml/loader.d b/source/dyaml/loader.d
index b1f6c18..cbce28d 100644
--- a/source/dyaml/loader.d
+++ b/source/dyaml/loader.d
@@ -179,8 +179,6 @@ struct Loader
                 reader_           = new Reader(streamBytes);
                 scanner_          = new Scanner(reader_);
                 parser_           = new Parser(scanner_);
-                resolver_         = new Resolver();
-                constructor_      = new Constructor();
             }
             catch(YAMLException e)
             {
@@ -211,8 +209,6 @@ struct Loader
                 reader_      = new Reader(cast(ubyte[])yamlData);
                 scanner_     = new Scanner(reader_);
                 parser_      = new Parser(scanner_);
-                resolver_    = new Resolver();
-                constructor_ = new Constructor();
             }
             catch(YAMLException e)
             {
@@ -267,6 +263,7 @@ struct Loader
         {
             try
             {
+                lazyInitConstructorResolver();
                 scope(exit) { done_ = true; }
                 auto composer = new Composer(parser_, resolver_, constructor_);
                 enforce(composer.checkNode(), new YAMLException("No YAML document to load"));
@@ -320,6 +317,7 @@ struct Loader
             scope(exit) { done_ = true; }
             try
             {
+                lazyInitConstructorResolver();
                 auto composer = new Composer(parser_, resolver_, constructor_);
 
                 int result = 0;
@@ -393,6 +391,14 @@ struct Loader
                                         .format(name_, e.msg));
             }
         }
+
+        // Construct default constructor/resolver if the user has not yet specified
+        // their own.
+        void lazyInitConstructorResolver() @safe
+        {
+            if(resolver_ is null)    { resolver_    = new Resolver(); }
+            if(constructor_ is null) { constructor_ = new Constructor(); }
+        }
 }
 
 unittest