For Object Sets, Pathnames, Modifer/Key/NodeChildren Arrays and Arrays.
The following virtual functions are defined on Value and implemented by those classes that support them to provide a collection mapping mechanism. Those that support mapping return true from the virtual function predicate is_collection(). The MAXScript 'for x in y ...' loop statement relies on these mapping functions, for example. Attempting to map a non-collection results in a descriptive MAXScript runtime error.
Some of the functions are driven by a mapping structure, 'node_map', defined below.
Only PathNames, ObjectSets and Nodes implement the '_path' variants. Mapping over a scene node Value (MAXNode instance), effectively maps over its descendants.
Value* map(node_map& m);
map node structure over collection
Value* map_path(PathName* path, node_map& m);
map node collection over values matching pathname
Value* find_first(BOOL (*test_fn)(INode* node, int level, void* arg),
void* test_arg);
find first node matching test
Value* get_path(PathName* path);
get the non-wild-card pathname-specified node
struct node_map
{
value_vfvfn_ptr; // virtual fn to map
value_cfcfn_ptr; // or, c fn to map (one or the other must be null)
Value**arg_list; // args to pass on...
intcount;
BOOL(*selector)(INode*, int, void*); // set selector fn
void*sel_arg; // arg for the selector
intget_index; // index if we are doing an indexed get
intget_count; // local running traverse count during get
Value**get_result_p; // ptr to result holder for indexed get
Array*collection; // append map results here if non-null (used // in for ... collect)
shortflags; // control flags
};
#define NM_INVERT0x0001 // invert map order, map parents last on
// the way out of the recursion
#define NM_SELECT0x0002 // applying a select, adjust clear flag
#define NM_GET 0x0004 // doing a get, return get_index'th item