Heap Object Type Information

Heap objects contain a type tag and are followed by a number of word-sized slots. The interpretation of the object contents depends on the type of the object.

Macro: scm_t_bits SCM_CELL_TYPE (SCM x)

Extract the first word of the heap object pointed to by x. This value holds the information about the cell type.

Macro: void SCM_SET_CELL_TYPE (SCM x, scm_t_bits t)

For a non-immediate Scheme object x, write the value t into the first word of the heap object referenced by x. The value t must hold a valid cell type.