From 8d3c10ca74af7c1360d62151ee7be82d8bfc0a8e Mon Sep 17 00:00:00 2001
From: Daniel Lemire <lemire@gmail.com>
Date: Thu, 26 Apr 2018 21:37:48 -0400
Subject: [PATCH] Create rapidjsondesign.md

---
 rapidjsondesign.md | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 rapidjsondesign.md

diff --git a/rapidjsondesign.md b/rapidjsondesign.md
new file mode 100644
index 00000000..3ffab785
--- /dev/null
+++ b/rapidjsondesign.md
@@ -0,0 +1,33 @@
+I looks like RapidJSON can process inputs at 4 cycles per byte. Rapidjson has a function that skips spaces and comments... it is obviously optimized with some SSE... 
+
+Everything else just a series of recursive calls with switch cases. It starts like this...
+
+```
+SkipWhitespaceAndComments<parseFlags>(is);
+ParseValue<parseFlags>(is, handler);
+```
+
+... which is just this...
+
+```
+    void ParseValue(InputStream& is, Handler& handler) {
+        switch (is.Peek()) {
+            case 'n': ParseNull  <parseFlags>(is, handler); break;
+            case 't': ParseTrue  <parseFlags>(is, handler); break;
+            case 'f': ParseFalse <parseFlags>(is, handler); break;
+            case '"': ParseString<parseFlags>(is, handler); break;
+            case '{': ParseObject<parseFlags>(is, handler); break;
+            case '[': ParseArray <parseFlags>(is, handler); break;
+            default :
+                      ParseNumber<parseFlags>(is, handler);
+                      break;
+
+        }
+    }
+```
+
+
+What RapidJSON does not do:
+
+- Lazy evaluation (it figures out the content of strings and numbers)
+- It does not do computed gotos