From 0bea335f570e86072427c96871c13780e621f17c Mon Sep 17 00:00:00 2001
From: Cameron Ross <elpenguino@gmail.com>
Date: Wed, 18 Apr 2018 15:21:13 -0300
Subject: [PATCH] massive speed increase for mapping construction

---
 source/dyaml/composer.d | 16 ++++++++++++----
 source/dyaml/node.d     | 16 ----------------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/source/dyaml/composer.d b/source/dyaml/composer.d
index 85c64b7..001869b 100644
--- a/source/dyaml/composer.d
+++ b/source/dyaml/composer.d
@@ -12,9 +12,11 @@ module dyaml.composer;
 
 import core.memory;
 
+import std.algorithm;
 import std.array;
 import std.conv;
 import std.exception;
+import std.range;
 import std.typecons;
 
 import dyaml.constructor;
@@ -314,12 +316,12 @@ final class Composer
                     else
                     {
                         auto temp = Node.Pair(key, value);
-                        merge(*pairAppender, temp);
+                        pairAppender.put(temp);
                     }
                 }
                 foreach(node; toMerge)
                 {
-                    merge(*pairAppender, flatten(node, startMark, endMark,
+                    pairAppender.put(flatten(node, startMark, endMark,
                                                  pairAppenderLevel + 1, nodeAppenderLevel));
                 }
             }
@@ -327,7 +329,7 @@ final class Composer
             else if(root.isSequence) foreach(ref Node node; root)
             {
                 if(!node.isType!(Node.Pair[])){error(node);}
-                merge(*pairAppender, flatten(node, startMark, endMark,
+                pairAppender.put(flatten(node, startMark, endMark,
                                              pairAppenderLevel + 1, nodeAppenderLevel));
             }
             else
@@ -368,7 +370,7 @@ final class Composer
                 //Not YAMLMerge, just add the pair.
                 else
                 {
-                    merge(*pairAppender, pair);
+                    pairAppender.put(pair);
                 }
             }
             foreach(node; toMerge)
@@ -376,6 +378,12 @@ final class Composer
                 merge(*pairAppender, flatten(node[0], startEvent.startMark, node[1],
                                              pairAppenderLevel + 1, nodeAppenderLevel));
             }
+            auto numUnique = pairAppender.data.dup
+                                .sort!((x,y) => x.key > y.key)
+                                .uniq!((x,y) => x.key == y.key)
+                                .walkLength;
+            enforce(numUnique == pairAppender.data.length,
+                    new ComposerException("Duplicate key found in mapping", parser_.getEvent().startMark));
 
             Node node = constructor_.node(startEvent.startMark, parser_.getEvent().endMark,
                                           tag, pairAppender.data.dup, startEvent.collectionStyle);
diff --git a/source/dyaml/node.d b/source/dyaml/node.d
index e60aa42..80ca94f 100644
--- a/source/dyaml/node.d
+++ b/source/dyaml/node.d
@@ -2195,22 +2195,6 @@ struct Node
 }
 
 package:
-// Merge a pair into an array of pairs based on merge rules in the YAML spec.
-//
-// The new pair will only be added if there is not already a pair
-// with the same key.
-//
-// Params:  pairs   = Appender managing the array of pairs to merge into.
-//          toMerge = Pair to merge.
-void merge(ref Appender!(Node.Pair[]) pairs, ref Node.Pair toMerge) @safe
-{
-    foreach(ref pair; pairs.data)
-    {
-        if(pair.key == toMerge.key){return;}
-    }
-    pairs.put(toMerge);
-}
-
 // Merge pairs into an array of pairs based on merge rules in the YAML spec.
 //
 // Any new pair will only be added if there is not already a pair