Avoid dropping const qualifier in casts

Adjusts casts to void dropping const qualifiers. This helps to avoid
mistakes, e.g. modifying string literals.

Also use size_t for length, similar to the upstream php interfaces.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/sp_config.h b/src/sp_config.h
index f957d15..f245943 100644
--- a/src/sp_config.h
+++ b/src/sp_config.h
@@ -188,7 +188,7 @@ typedef struct {
 
 typedef struct {
   SP_PARSE_FN((*func));
-  char *token;
+  const char *token;
   void *retval;
 } sp_config_keyword;