Allow user-defined context fields

spec/test_user_context_fields.c

@@ -0,0 +1,19 @@
+#include "testparser.h"
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int main()
+{
+    char const * input = "aaa\n\n\na\n    # comment 1\na  a    aa\n\naa\n#    comment 2\na\n";
+    p_context_t context;
+    p_context_init(&context, (uint8_t const *)input, strlen(input));
+    assert(p_parse(&context) == P_SUCCESS);
+
+    fprintf(stderr, "comments: %s", context.comments);
+    fprintf(stderr, "acount: %u\n", context.acount);
+    free(context.comments);
+
+    return 0;
+}