var.h

smallbasic for linux

/**
*	SmallBasic Variable Manager.
*
*	2000-05-27, Nicholas Christopoulos
*
*	This program is distributed under the terms of the GPL v2.0 or later
*	Download the GNU Public License (GPL) from www.gnu.org
*/

#if !defined(_sb_var_h)
#define _sb_var_h

#include "pmem.h"

#define	V_NULL		0
#define	V_INT		0
#define	V_NUM		2
#define	V_STR		3
#define	V_ARRAY		4
#define	V_PTR		5
#define	V_ANY		6

// predefined system variables - index
#define	SYSVAR_OSVER		0
#define	SYSVAR_OSNAME		1
#define	SYSVAR_SBVER		2
#define	SYSVAR_PI			3
#define	SYSVAR_XMAX			4
#define	SYSVAR_YMAX			5
#define	SYSVAR_BPP			6
#define	SYSVAR_TRUE			7
#define	SYSVAR_FALSE		8
#define	SYSVAR_LINECHART	9
#define	SYSVAR_BARCHART		10

//
#define	MAXDIM		4		// think before increase this, (possible stack overflow)

#if defined(__cplusplus)
extern "C" {
#endif

// needed for BCDUMP
struct keyword_s {
	char	name[16];
	byte	code;
	};
extern struct keyword_s keyword_table[];

// VARIANT DATA TYPE
struct var_s	{
	byte	type;
	byte	const_flag;

	// value 
	double	n;
	long	i;

	// generic ptr
	byte	*ptr;
	int		size;				// the size of ptr, for array the number of the variables

	// array
	int		lbound[MAXDIM];		// bounds 
	int		ubound[MAXDIM];
	byte	maxdim;
	};
typedef struct var_s var_t;
typedef var_t* var_p_t;

struct lab_s	{
	word	ip;
	};
typedef struct lab_s lab_t;

struct stknode_s	{
	byte	type;
	word	exit_ip;
	union	{

		struct {
			var_t	*var_ptr;		// 'FOR' variable
			word	to_expr_ip;		// IP of 'TO' expression
			word	step_expr_ip;	// IP of 'STEP' expression
			word	jump_ip;		// code block IP
			} vfor;					// CMD: FOR-TO-NEXT

		struct {
			word	lcond;	// result of the last condition
			} vif;			// CMD: IF/ELIF

		struct {
			word	ret_ip;	// return ip
			} vgosub;		// CMD: GOSUB

		struct {
			word	ret_ip;	// return ip
			word	pcount; // number of parameters
			word	rvid; 	// return-variable ID
			var_t*	retvar;	// return-variable data
			} vcall;		// CMD: CALL UDP/F

		struct {
			word	vid;	// variable index in tvar
			var_t	*vptr;	// previous variable
			} vdvar;		// CMD: Create dynamic variable (LOCAL or PARAMETER)

		struct {
			word	vcheck;	// checks (1=BYVAL ONLY, 3=BYVAL|BYREF, 2=BYREF ONLY)
			var_t	*res;	// variable pointer (for BYVAL this is a clone)
			} param;		// CMD: parameter (CALL UDP/F)

		} x;
	};
typedef struct stknode_s stknode_t;

var_t*	v_new();
int		v_is_nonzero(var_t *v)						;
double	v_getval(var_t *v)							;
long	v_igetval(var_t *v)							;
#define v_getint(a)	v_igetval((a))
int		v_compare(var_t *a, var_t *b)				;
int		v_addtype(var_t *a, var_t *b)				;
void	v_add(var_t *result, var_t *a, var_t *b)	;
void	v_init(var_t *v)							;
void	v_free(var_t *v)							;
void	v_set(var_t *dest, const var_t *src)		;
void	v_inc(var_t *a, var_t *b)					;
int		v_sign(var_t *x)							;
var_t*	v_getelemptr(var_t *v, word index)			;
void	v_createstr(var_t *v, const char *src)		;
void	v_tostr(var_t *arg)							;
var_t*	v_clone(const var_t *source);
void	v_resize_array(var_t *v, int size);

//
void	rt_raise(const char *fmt, ...);

dword	code_getnext32(void)						;
double	code_getnext64f(void)						;
int		code_checkop(byte op)						;
int		code_checkop_s(byte *str)					;
void	code_jump_label(word label_id)				;
//void	code_jump(word id)							;
#define	code_jump(newip)			prog_ip=(newip)
void	code_push(stknode_t *node)					;
void	code_pop(stknode_t *node)					;
var_t	*code_getvarptr(void)						;
int		code_isnullarray_nc(int start)			;
int		code_isnullarray(void);

#define	code_peek()			prog_source[prog_ip]
#define	code_getnext()		prog_source[prog_ip++]

#define	code_skipnext()		prog_ip++
#define	code_skipnext16()	prog_ip+=2

#if defined(_PalmOS)	// Motorola CPUs
#define	code_getnext16()	(prog_ip+=2, (prog_source[prog_ip-2]<<8)|prog_source[prog_ip-1])
#define	code_peeknext16()	((prog_source[prog_ip]<<8)|prog_source[prog_ip+1])
#define	code_peek16(o) 		((prog_source[prog_ip+(o)]<<8)|prog_source[prog_ip+(o)+1])
#else	// Intel CPUs
#define	code_getnext16()	(prog_ip+=2, (prog_source[prog_ip-1]<<8)|prog_source[prog_ip-2])
#define	code_peeknext16()	((prog_source[prog_ip+1]<<8)|prog_source[prog_ip])
#define	code_peek16(o)		((prog_source[prog_ip+(o)+1]<<8)|prog_source[prog_ip+(o)])
#endif

void	setsysvar_int(int index, long val);
void	setsysvar_num(int index, double val);

#if defined(__cplusplus)
}
#endif

#endif