[ADD] Add basic Matrix ID parser

src/MatrixID.c

@@ -0,0 +1,34 @@
+#include <Matrix.h>
+
+#include <Cytoplasm/Memory.h>
+
+#include <string.h>
+
+UserID *
+MatrixParseID(char *user)
+{
+    UserID *ret = NULL;
+    char *localstart, *serverstart;
+    if (!user || *user != '@')
+    {
+        return NULL;
+    }
+
+    localstart = user + 1;
+    serverstart = strchr(user, ':');
+    if (!*localstart || !serverstart || localstart == serverstart)
+    {
+        return NULL;
+    }
+    if (!*++serverstart)
+    {
+        return NULL;
+    }
+
+    ret = Malloc(sizeof(*ret));
+    memset(ret, '\0', sizeof(*ret));
+    memcpy(ret->localpart, localstart, serverstart - localstart - 1);
+    memcpy(ret->server, serverstart, strlen(serverstart));
+
+    return ret;
+}