/*
 * Define all nodes used by the interpreter.
 * It is extremly important that these nodes are as small as possible,
 * because they are the outstandingly most allocated data structure.
 *
 * Common for all nodes are:
 * type:    The type of the node.
 * line:    The line in the source. The 4 top bits store the
 *      basic type of the node (L_ something). Use L_MASK to mask
 *      out either the line number or basic type.
 */

#define L_SINGLE        0x1000
struct lnode_single {
  unsigned short type;
  unsigned short line;
};

#define L_NUMBER        0x2000
struct lnode_number {
  unsigned short type;
  unsigned short line;
  int number;
};

#define L_NAME          0x3000
struct lnode_name {
  unsigned short type;
  unsigned short line;
  char *name;
};

#define L_VARIABLE      0x4000
struct lnode_variable {
  unsigned short type;
  unsigned short line;
  /* char *name; *//* A real memory hog ! */
  int number;
};

#define L_1         0x5000
struct lnode_1 {
  unsigned short type;
  unsigned short line;
  struct lnode *expr;
};

#define L_2         0x6000
struct lnode_2 {
  unsigned short type;
  unsigned short line;
  struct lnode *expr1;
  struct lnode *expr2;
};

#define L_3         0x7000
struct lnode_3 {
  unsigned short type;
  unsigned short line;
  struct lnode *expr1;
  struct lnode *expr2;
  struct lnode *expr3;
};

#define L_DEF           0x8000
struct lnode_def {
  unsigned short type;
  unsigned short line;
  char *name;
  struct lnode *block;
  struct lnode_def *next;
  unsigned short num_var;
  unsigned short num_ref;
};

#define L_VAR_DEF       0x9000
struct lnode_var_def {
  unsigned short type;
  unsigned short line;
  char *name;
  struct lnode_var_def *next;
  int num_var;
};

#define L_FUNCALL       0xa000
struct lnode_funcall {
  unsigned short type;
  unsigned short line;
  struct lnode *expr;
  char *name;
};

#define L_BLOCK         0xb000
struct lnode_block {
  unsigned short type;
  unsigned short line;
  int num_nodes;                /* Number of nodes in this block */
  char *block;
};

#define L_MASK          0xf000
#define L_MAX           0xb000  /* Highest number */
#define L_SHIFT         12      /* Number of bits to shift */
struct lnode {
  unsigned short type;
  unsigned short line;
  struct lnode *a1, *a2, *a3;   /* Statements inside this statement */
};

struct lnode_number *alloc_lnode_number(int type, int number);
struct lnode_block *alloc_lnode_block(struct lnode *p);
struct lnode_name *alloc_lnode_name(int type, char *name);
struct lnode_variable *alloc_lnode_variable(int type, int number);
struct lnode_1 *alloc_lnode_1(int type, struct lnode *expr);
struct lnode_2 *alloc_lnode_2(int type, struct lnode *expr1, struct lnode *expr2);
struct lnode_3 *alloc_lnode_3(int type, struct lnode *expr1, struct lnode *expr2, struct lnode *expr3);
struct lnode_def *alloc_lnode_def(int type, char *name, struct lnode *block, int num_var);
struct lnode_funcall *alloc_lnode_funcall(int type, char *name, struct lnode *arg);
void alloc_lnode_var_def(int type, char *name, int num_var);
struct lnode_single *alloc_lnode_single(int type);
void print_lnode_status(int tot_before_this);
void compute_lnode_size(void);
void free_lnode(struct lnode *p, int update_count);
void add_prog_ref(struct lnode_def *p);
int free_prog(struct lnode_def *p);
void free_sub_part(struct lnode *p, int do_free);

extern struct lnode_var_def *prog_status;

extern int lnode_size[];