Initial revision

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@1 72102866-910b-0410-8b05-ffd578937521

Examples/textcoding.m

@@ -0,0 +1,100 @@
+/* A demonstration of writing and reading GNU Objective C objects to a file,
+   in human-readable text format.
+   Look at the file "textcoding.txt" after running this program to see the
+   text archive format.
+   */
+
+#include <objects/TextCoder.h>
+#include <objects/StdioStream.h>
+#include <objects/Set.h>
+#include <objects/EltNodeCollector.h>
+#include <objects/LinkedList.h>
+#include <objects/LinkedListEltNode.h>
+
+int main()
+{
+  id set, ll;
+  id stream;
+  id coder;
+  const char *n;
+
+  /* Create a Set of int's
+     and a LinkedList of float's */
+  set = [[Set alloc] initWithType:@encode(int)];
+  ll = [[EltNodeCollector alloc] initWithType:@encode(float)
+	nodeCollector:[[LinkedList alloc] init]
+	nodeClass:[LinkedListEltNode class]];
+
+  /* Populate the Set and display it */
+  [set addElement:1234567];
+  [set addElement:2345678];
+  [set addElement:3456789];
+  [set addElement:4567891];
+  [set addElement:5678912];
+  [set printForDebugger];
+
+  /* Populate the LinkedList and display it */
+  [ll addElement:1.2f];
+  [ll addElement:(float)3.4];
+  [ll addElement:(float)5.6];
+  [ll addElement:(float)7.8];
+  [ll addElement:(float)9.0];
+  [ll printForDebugger];
+
+  /* Write them to a file */
+  stream = [[StdioStream alloc] 
+	    initWithFilename:"./textcoding.txt"
+	    fmode:"w"];
+  coder = [[TextCoder alloc] initEncodingOnStream:stream];
+  [coder encodeObject:set withName:"Test Set"];
+  [coder encodeObject:ll withName:"Test EltNodeCollector LinkedList"];
+
+  /* Free the objects */
+  [coder free];
+  [set free];
+  [ll free];
+
+  /* Read them back in from the file */
+  /* First init the stream and coder */
+  stream = [[StdioStream alloc] 
+	    initWithFilename:"./textcoding.txt"
+	    fmode:"r"];
+  coder = [[TextCoder alloc] initDecodingOnStream:stream];
+
+  /* Read in the Set */
+  [coder decodeObjectAt:&set withName:&n];
+  printf("got object named %s\n", n);
+  /* The name was malloc'ed by the Stream, free it */
+  (*objc_free)((void*)n);
+
+  /* Read in the LinkedList */
+  [coder decodeObjectAt:&ll withName:&n];
+  printf("got object named %s\n", n);
+  /* The name was malloc'ed by the Stream, free it */
+  (*objc_free)((void*)n);
+
+  /* Display what we read, to make sure it matches what we wrote */
+  [set printForDebugger];
+  [ll printForDebugger];
+
+  /* Free the objects */
+  [coder free];
+  [set free];
+  [ll free];
+  
+  exit(0);
+}
+
+/* Some notes:
+
+   This program is a great example of how allocating and freeing
+   memory is very screwed up:
+
+   * The Stream allocates the name, we have to free it.
+
+   * The Coder free's its Stream when the Coder is free'd, but we
+   were the ones to create it.
+
+   These difficult and ad-hoc rules will be fixed in the future.
+
+*/