tokenstate
struct tokenstate tokenstate[LEVELS_PER_BLOCK];
static inline struct tokenstate *
return &stack->tokenstate[stack->cur];
static inline struct tokenstate *
return &stack->tokenstate[stack->cur - 1];
return &stack->tokenstate[0];
return &stack->prev->tokenstate[LEVELS_PER_BLOCK - 1];
struct tokenstate *os, *ts;