/* lisp.h   by Michael Thorpe   2017-05-29 */

#ifndef LISP_H
#define LISP_H

#ifdef USE_FLOAT
/* Define this if your machine can't handle floating-point division by 0 */
/* #define NO_FDIV_BY_0 */
#endif

#ifdef USE_BIGINT
#include <gmp.h>
#endif

/* Only necessary for stream objects: */
#include <stdio.h>

typedef struct obj obj;
typedef struct objtype objtype;

struct objtype {
	char *name;
	obj *nameobj;
	obj *(*tostring)(obj *);
	void (*predropobj)(obj *); /* Called when object is put on the freelist */
	void (*dropobj)(obj *); /* Called when object is to be discarded */
	objtype *next;
	int (*init)(); /* Called when objtype is registered */
	void (*exit)(); /* Called when objtype is to be unregistered */
};

union rawfuncptr {
	obj *(*ns0)();
	obj *(*ns1)(obj *);
	obj *(*ns2)(obj *,obj *);
	obj *(*ns3)(obj *,obj *,obj *);
};

struct wordextra {
	char *data;
	unsigned long len;
	struct wordextra *previnhash,*nextinhash;
	obj *obj; /* doesn't INCREF/DECREF */
};

struct obj {
	objtype *type;
	union {
		unsigned long refcount;
		obj *nextfree;
	} rcnf;
	union {
#ifdef USE_BIGINT
		mpz_t bi;
#endif
		struct c {
			obj *a;
			obj *d;
		} c;
		signed long i;
#ifdef USE_FLOAT
		double f;
#endif
		obj *o;
		struct rawfunc {
			unsigned int numargs:2;
			union rawfuncptr rawfuncptr;
		} rawfunc;
		struct bytefunc {
			obj *code;
			obj *objs;
		} bytefunc;
		struct s {
			char *data;
			unsigned long len;
		} s;
		struct stream {
			unsigned int readable:1;
			unsigned int writable:1;
			unsigned int closable:1;
			FILE *f;
		} stream;
		struct word {
			struct wordextra *extra;
			obj *value;
		} word;
	} value;
#ifdef DEBUG
	obj *prev,*next;
#endif
};

extern objtype
#ifdef USE_BIGINT
	bigint_objtype,
#endif
	bytefunc_objtype,
	cons_objtype,
#ifdef USE_FLOAT
	float_objtype,
#endif
	integer_objtype,
	nil_objtype,
	quote_objtype,
	rawfunc_objtype,
	stream_objtype,
	string_objtype,
	word_objtype;

#ifdef USE_BIGINT
/* bigint.c */
obj *addb(obj *a,obj *b);
obj *bitselectb(obj *a,obj *if0,obj *if1);
obj *div2b(obj *a,obj *b);
obj *mulb(obj *a,obj *b);
obj *numcmpb(obj *a,obj *b,int desired);
obj *string_to_bigint(obj *str);
obj *subb(obj *a,obj *b);
#ifdef USE_FLOAT
obj *bigint_to_float(obj *bi);
#endif
#endif

/* bytefunc.c */

/* cons.c */
#define CAR(o) ((o)->value.c.a)
#define CDR(o) ((o)->value.c.d)
obj *cons(obj *a,obj *d);

#ifdef USE_FLOAT
/* float.c */
obj *addf(obj *a,obj *b);
obj *div2f(obj *a,obj *b);
obj *mulf(obj *a,obj *b);
obj *numcmpf(obj *a,obj *b,int desired);
obj *string_to_float(obj *str);
obj *subf(obj *a,obj *b);
#endif

/* integer.c */
extern obj *divideby0error;
extern obj trueobj;
obj *add(obj *a,obj *b);
obj *bitselect(obj *a,obj *if0,obj *if1);
obj *asr(obj *a,obj *b);
obj *div2(obj *a,obj *b); /* stdlib.h sometimes has a div() function */
obj *mul(obj *a,obj *b);
obj *numcmp(obj *a,obj *b,int desired);
obj *sub(obj *a,obj *b);

/* nil.c */
extern obj nilobj;

/* preload.c */
int preload_init();

/* quote.c */
obj *quoteobj(obj *o);
obj *unquote(obj *o);

/* rawfunc.c */
obj *applyrawfunc(obj *func,obj *args);

/* stream.c */

/* string.c */
obj *new_string(const char *data,unsigned long len);

/* throw.c */
extern obj
	*exception,
	*exceptionvalue;
obj *throw(obj *type,obj *value);
obj *throwaccesserror(obj *value);
obj *throwargumenterror(obj *value);
obj *throwoom();
obj *throwrangecheck(obj *value);
obj *throwtypeerror(obj *value);
int throw_init();
void throw_exit();

/* util.c */
#ifdef DEBUG
#define DECREF(o) real_decref((o),__FILE__,__LINE__)
void real_decref(obj *o,const char *file,int line);
#define INCREF(o) real_incref((o),__FILE__,__LINE__)
obj *real_incref(obj *o,const char *file,int line);
extern unsigned long total_objects;
#else
#define DECREF(o) do{if(!--(o)->rcnf.refcount)drop_object(o);}while(0)
#define INCREF(o) ((o)->rcnf.refcount++,(o))
#endif
void drop_object(obj *o);
obj *new_object(objtype *type);
int register_objtype(objtype *type);
int clean_up();

/* vm.c */
int run_vm();
int vm_init();
void vm_exit();

/* word.c */
obj *lookup(obj *name);
obj *define(obj *name,obj *value);
obj *set(obj *name,obj *value);
obj *undefine(obj *name);
int store_builtin(unsigned int numargs,const char *name,obj *(*rawfunc)());
obj *new_word(const char *data,unsigned long len);
int store_object(const char *name,obj *o);

#define store_builtin_ns0(name,func) ((int (*)(unsigned int numargs,const char *,obj *(*)()))store_builtin)(0,name,func)
#define store_builtin_ns1(name,func) ((int (*)(unsigned int numargs,const char *,obj *(*)(obj *)))store_builtin)(1,name,func)
#define store_builtin_ns2(name,func) ((int (*)(unsigned int numargs,const char *,obj *(*)(obj *,obj *)))store_builtin)(2,name,func)
#define store_builtin_ns3(name,func) ((int (*)(unsigned int numargs,const char *,obj *(*)(obj *,obj *,obj *)))store_builtin)(3,name,func)

#endif