/*************************************************************************
* *
* BEAM -> Basic Extended Andorra Model *
* BEAM extends the YAP Prolog system to support the EAM *
* *
* Copyright: Ricardo Lopes and NCC - University of Porto, Portugal *
* *
**************************************************************************
* comments: eam compiler data structures and routines *
*************************************************************************/
#define Print_Code 0
/* To help on compiler debuging
1 -> show predicates info
2 -> show YAP abstract machine code (YAAM)
4 -> show YAAM after transformation
8 -> show indexing code
16 -> show EAM intermediate code
32 -> show EAM intermediate code with direct_calls
128 -> show EAM abstrac machine code
*/
#define Variavel 1
#define Lista 2
#define Estrutura 4
#define Constante 8
typedef unsigned long Cell;
typedef struct PCODE{
struct PCODE *nextInst;
int op, new1;
unsigned long new4;
} CInstr;
struct Clauses {
unsigned int idx; /* info for indexing on first arg */
Cell val; /* atom or functor in first arg */
unsigned int nr_vars; /* nr of local vars */
struct Predicates *predi; /* predicate struct */
int side_effects; /* clause has side effects */
Cell *code;
struct Clauses *next; /* next clause within the same predicate */
};
struct HASH_TABLE {
Cell value;
Cell *code;
struct HASH_TABLE *next;
};
struct Predicates { /* To register information about predicates */
unsigned long id;
unsigned char *name;
unsigned int arity;
unsigned int nr_alt; /* nr of alternativas */
unsigned int calls; /* nr of existent calls to this predicate */
struct Clauses *first;
struct Clauses *last;
int idx; /* is code indexed ? 0= needs compilation -1= no indexing possible 1= indexed */
unsigned int idx_var; /* nr clauses with 1st argument var */
unsigned int idx_list; /* nr clauses with 1st argument list */
unsigned int idx_atom; /* nr clauses with 1st argument atom */
unsigned int idx_functor; /* nr clauses with 1st argument functor */
short int eager_split; /* allow eager splitting */
Cell *code; /* try, retry and trust code or Indexing code */
struct HASH_TABLE **atom;
struct HASH_TABLE **functor;
Cell *list;
Cell *vars;
struct Predicates *next;
};
/**************************** EAM TRUE STUFF *************/
struct SUSPENSIONS {
struct AND_BOX *and_box; /* And_box where the variable has suspended */
short int reason; /* suspended before executing call number nr_call */
struct SUSPENSIONS *next; /* Pointer to the next suspention */
struct SUSPENSIONS *prev;
};
struct SUSPENSIONS_VAR {
struct AND_BOX *and_box; /* And_box where the variable has suspended */
struct SUSPENSIONS_VAR *next; /* Pointer to the next suspention */
};
struct PERM_VAR {
Cell value; /* value assigned to the variable */
struct AND_BOX *home; /* pointer to the goal_box structure of the variable */
Cell *yapvar;
struct SUSPENSIONS_VAR *suspensions; /* Pointer to a Suspension List */
struct PERM_VAR *next;
};
struct EXTERNAL_VAR { /* to be used as some kind of trail */
Cell value; /* value assign to the variable */
struct PERM_VAR *var; /* pointer to the local_var struct */
struct EXTERNAL_VAR *next;
};
struct status_and {
struct OR_BOX *call; /* POINTER TO A OR_BOX */
Cell *locals; /* temporary vars vector */
Cell *code; /* Pointer to the start code */
int state; /* State of the OR_BOX */
struct status_and *previous;
struct status_and *next;
};
struct status_or {
struct AND_BOX *alternative; /* POINTER TO A AND_BOX */
Cell *args; /* Saved Arguments */
Cell *code; /* Pointer to Start Code */
int state; /* State of the AND_BOX */
struct status_or *previous;
struct status_or *next;
};
struct OR_BOX {
struct AND_BOX *parent;
struct status_and *nr_call; /* order of this box */
short int nr_all_alternatives; /* number of existing alternatives */
struct status_or *alternatives; /* alternatives of the or_box */
short int eager_split;
};
struct AND_BOX {
struct OR_BOX *parent; /* pointer to the parent or-box */
struct status_or *nr_alternative; /* This box is alternative id */
short int nr_all_calls; /* numger of all goals */
struct PERM_VAR *perms;
struct status_and *calls;
short int level; /* indicates the level in the tree */
struct EXTERNAL_VAR *externals; /* pointer to a list of external_vars */
struct SUSPENSIONS *suspended; /* pointer to a list of suspended boxes */
short int side_effects; /* to mark if are calls to builtins with side_efects (like write) */
};
/* TYPE OF STATES */
#define ZERO 0 /* No State yet */
#define SUCCESS 1
#define FAILS 2
#define READY 4 /* Is ready to start execution */
#define RUNNING 8 /* Is running */
#define RUNAGAIN 16 /* Is running again */
#define SUSPEND 32 /* Has suspended */
#define WAKE 64 /* Was Suspended, but now is Ready again */
#define CHANGED 128 /* Has received some change on it's external variables, needs to re-run */
#define END 256 /* Has suspended on end, on wake up can pass to a success state */
#define WAITING 512 /* The clause is waiting for the previous predicates to leave the Suspended state */
#define FAILED 1024 /* has failed */
#define CUT_RIGHT 2048
#define SKIP_VAR 4096
#define LEFTMOST_PARENT 8192
#define FIRST 16384
#define LEFTMOST 32768
#define WAITING_TO_BE_FIRST (WAITING + FIRST)
#define WAITING_TO_BE_LEFTMOST (WAITING + LEFTMOST)
#define WAITING_TO_BE_LEFTMOST_PARENT (WAITING + LEFTMOST_PARENT)
#define WAITING_TO_CUT (WAITING + CUT_RIGHT)
#define WAITING_SKIP_VAR (WAITING + SKIP_VAR)
#define SUSPEND_END (SUSPEND+END)
#define WAKE_END (WAKE+END)
#define NORMAL_SUSPENSION 0
#define LEFTMOST_SUSPENSION 1
#define WAIT_SUSPENSION 2
#define CUT_SUSPENSION 3
#define WRITE_SUSPENSION 4
#define VAR_SUSPENSION 5
#define YAP_VAR_SUSPENSION 6
/* TYPE OF SIDE_EFFECTS */
#define WRITE 1
#define COMMIT 2
#define VAR 4
#define SEQUENCIAL 8
#define CUT 32 /* Greater than 32 always cut */