add cJSON_Utils which includes JSON Pointer implementation

git-svn-id: svn://svn.code.sf.net/p/cjson/code@63 e3330c51-1366-4df0-8b21-3ccf24e3d50e

Author: DaveGamble

cJSON_Utils.c

@@ -0,0 +1,43 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "cJSON_Utils.h"
+
+cJSON *cJSONUtils_GetPointer(cJSON *object,const char *pointer)
+{
+	cJSON *target=object;int which=0;const char *s=0;int len=0;char *element=0,*e=0;
+	
+	while (*pointer=='/' && object)
+	{
+		pointer++;
+		if (object->type==cJSON_Array)
+		{
+			which=0;
+			while (*pointer>='0' && *pointer<='9') {which*=10;which+=*pointer++ - '0';}
+			if (*pointer && *pointer!='/') return 0;
+			object=cJSON_GetArrayItem(object,which);
+		}
+		else if (object->type==cJSON_Object)
+		{
+		
+			s=pointer;len=0;
+			while (*s && *s!='/') {if (*s!='~') len++; s++;}
+			e=element=malloc(len+1); if (!element) return 0;
+			element[len]=0;
+
+			while (*pointer && *pointer!='/')
+			{
+				if (*pointer=='~' && pointer[1]=='0')		*e++='~',pointer+=2;
+				else if (*pointer=='~' && pointer[1]=='1')	*e++='/',pointer+=2;
+				else if (*pointer=='~')						{free(element); return 0;}	// Invalid encoding.
+				else										*e++=*pointer++; 
+			}
+			object=cJSON_GetObjectItem(object,element);
+			free(element);
+		}
+		else return 0;
+	}
+	return object;
+}
+
+

cJSON_Utils.h

@@ -0,0 +1,5 @@
+#include "cJSON.h"
+
+// Implement RFC6901 (https://tools.ietf.org/html/rfc6901) JSON Pointer spec.
+cJSON *cJSONUtils_GetPointer(cJSON *object,const char *pointer);
+

test_utils.c

@@ -0,0 +1,30 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "cJSON_Utils.h"
+
+int main()
+{
+	const char *json="{"
+		"\"foo\": [\"bar\", \"baz\"],"
+		"\"\": 0,"
+		"\"a/b\": 1,"
+		"\"c%d\": 2,"
+		"\"e^f\": 3,"
+		"\"g|h\": 4,"
+		"\"i\\\\j\": 5,"
+		"\"k\\\"l\": 6,"
+		"\" \": 7,"
+		"\"m~n\": 8"
+	"}";
+   
+	const char *tests[12]={"","/foo","/foo/0","/","/a~1b","/c%d","/e^f","/g|h","/i\\j","/k\"l","/ ","/m~0n"};
+   
+	printf("JSON Pointer Tests\n");
+	cJSON *root=cJSON_Parse(json);
+	for (int i=0;i<12;i++)
+	{
+		printf("Test %d:\n%s\n\n",i+1,cJSON_Print(cJSONUtils_GetPointer(root,tests[i])));
+	}
+
+
+}