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typedef struct Term Term;
typedef struct Binding Binding;
typedef struct Goal Goal;
typedef struct Choicepoint Choicepoint;
typedef int (*Builtin)(Term *, Term *, Binding **);
struct Term
{
int tag;
Rune *text;
int arity;
Term *next;
Term *children;
int numbertype;
vlong ival;
double dval;
uvlong clausenr;
};
struct Binding
{
Rune *name;
uvlong nr; /* Unique number for each clause. Every time a clause is used, it gets a new number. */
Term *value;
Binding *next;
};
struct Goal
{
Term *goal;
Term *catcher; /* When this is non-nil, the goal is a catch frame, goal is the recovery. */
Goal *next;
};
struct Choicepoint
{
Goal *goalstack;
Term *retryclause;
uvlong id; /* Unique number for each clause. Used to know where to cut to. */
Choicepoint *next;
};
/* Sorted so that a lower value means it comes earlier in the standard ordering */
enum {
VariableTerm,
NumberTerm,
AtomTerm,
CompoundTerm,
};
enum {
NumberFloat,
NumberInt,
};
int debug;
Term *initgoals;
/* Flags */
enum {
DoubleQuotesChars,
DoubleQuotesCodes,
DoubleQuotesAtom,
};
int flagdoublequotes;
/* Staate of the running system */
Choicepoint *choicestack;
Goal *goalstack;
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