/*	SC	A Spreadsheet Calculator
 *		Lexical analyser
 *
 *		original by James Gosling, September 1982
 *		modifications by Mark Weiser and Bruce Israel,
 *			University of Maryland
 *
 *              More mods Robert Bond, 12/86
 *		More mods by Alan Silverstein, 3/88, see list of changes.
 *		$Revision: 1.2 $
 *
 */


#include <sys/types.h>
#include <string.h>

#if defined(BSD42) || defined(BSD43)
#include <sys/ioctl.h>
#endif 

#ifdef IEEE_MATH
#include <ieeefp.h>
#endif /* IEEE_MATH */

#include <curses.h>
#include <signal.h>
#include <setjmp.h>
#include "sc.h"
#include <ctype.h>

#ifdef NONOTIMEOUT
#define	notimeout(a1, a2)
#endif

#ifdef VMS
#include "gram_tab.h"
typedef union {
    int ival;
    double fval;
    struct ent *ent;
    struct enode *enode;
    char *sval;
    struct range_s rval;
} YYSTYPE;
extern YYSTYPE yylval;
extern int VMS_read_raw;   /*sigh*/
#else	/* VMS */
#if defined(MSDOS)
#include "y_tab.h"
#else
#include "y.tab.h"
#endif /* MSDOS */
#endif /* VMS */

#ifdef hpux
extern YYSTYPE yylval;
#endif /* hpux */

char *strtof();

jmp_buf wakeup;
jmp_buf fpe_buf;

#ifdef SIGVOID
void
#endif
fpe_trap(signo)
int signo;
{
#if defined(i386) && !defined(M_XENIX)
	asm("	fnclex");
	asm("	fwait");
#else
#ifdef IEEE_MATH
	(void)fpsetsticky((fp_except)0);	/* Clear exception */
#endif /* IEEE_MATH */
#ifdef PC
	_fpreset();
#endif
#endif
    longjmp(fpe_buf, 1);
}

struct key {
    char *key;
    int val;
};

struct key experres[] = {
#include "experres.h"
    0, 0};

struct key statres[] = {
#include "statres.h"
    0, 0};

int
yylex ()
{
    register char *p = line+linelim;
    int ret;
    while (isspace(*p)) p++;
    if (*p == '\0') ret = -1;
    else if (isalpha(*p)) {
	char *tokenst = p;
	register tokenl;
	register struct key *tblp;
	tokenl = 0;
	/*
	 * This picks up either 1 or 2 alpha characters (a column) or
	 * tokens with at least three leading alphas and '_' or digits
	 * (a function or token or command or a range name)
	*/
	while (isalpha(*p) || ((*p == '_') || isdigit(*p)) && (tokenl > 2)) {
	    p++;
	    tokenl++;
	}
	if (tokenl <= 2) { /* a COL is 1 or 2 char alpha
		(but not pi, ln, fv, pv, if -- this should be fixed!) */
	    if (tokenl == 2 && tokenst[0] == 'p' && tokenst[1] == 'i') {
		ret = K_PI;
	    } else if (tokenl == 2 && tokenst[0] == 'l' && tokenst[1] == 'n') {
		ret = K_LN;
	    } else if (tokenl == 2 && tokenst[0] == 'f' && tokenst[1] == 'v') {
		ret = K_FV;
	    } else if (tokenl == 2 && tokenst[0] == 'p' && tokenst[1] == 'v') {
		ret = K_PV;
	    } else if (tokenl == 2 && tokenst[0] == 'i' && tokenst[1] == 'f') {
		ret = K_IF;

	    } else {
		ret = COL;
		yylval.ival = atocol (tokenst, tokenl);
	    }
	} else {
	    ret = WORD;
	    for (tblp = linelim ? experres : statres; tblp->key; tblp++)
		    if (((tblp->key[0]^tokenst[0])&0137)==0
		     && tblp->key[tokenl]==0) {
			register i = 1;
			while (i<tokenl && ((tokenst[i]^tblp->key[i])&0137)==0)
			    i++;
			if (i>=tokenl) {
			    ret = tblp->val;
			    break;
			}
		    }
	    if (ret==WORD) { 
		struct range *r;
		if (r = find_range(tokenst, tokenl,
				   (struct ent *)0, (struct ent *)0)) {
		    yylval.rval.left = r->r_left;
		    yylval.rval.right = r->r_right;
		    if (r->r_is_range)
		        ret = RANGE;
		    else
			ret = VAR;
		} else {
		    linelim = p-line;
		    yyerror ("Unintelligible word");
		}
	    }
	}
    } else if ((*p == '.') || isdigit(*p)) {
#ifdef SIGVOID
	void (*sig_save)();
#else
	int (*sig_save)();
#endif
	double v = 0.0;
	int temp;
	char *nstart = p;

	sig_save = signal(SIGFPE, fpe_trap);
	if (setjmp(fpe_buf)) {
	    (void) signal(SIGFPE, sig_save);
	    yylval.fval = v;
	    error("Floating point exception\n");
	    return FNUMBER;
	}

	if (*p != '.') {
	    do v = v*10.0 + (double) ((unsigned) *p - '0');
	    while (isdigit(*++p));
	}
	if (*p=='.' || *p == 'e' || *p == 'E') {
	    ret = FNUMBER;
	    p = strtof(nstart, &yylval.fval);
	} else {
	    /* A NUMBER must hold at least MAXROW and MAXCOL */
	    /* This is consistent with a short row and col in struct ent */
	    if (v > (double)32767 || v < (double)-32768) {
		ret = FNUMBER;
		yylval.fval = v;
	    } else {
		temp = (int)v;
		if((double)temp != v) {
		    ret = FNUMBER;
		    yylval.fval = v;
		} else {
		    ret = NUMBER;
		    yylval.ival = temp;
		}
	    }
	}
	(void) signal(SIGFPE, sig_save);
    } else if (*p=='"') {
	char *ptr;
        ptr = p+1;	/* "string" or "string\"quoted\"" */
        while(*ptr && ((*ptr != '"') || (*(ptr-1) == '\\')))
		ptr++;
        ptr = scxmalloc((unsigned)(ptr-p));
	yylval.sval = ptr;
	p += 1;
	while (*p && ((*p != '"') || (*(p-1) == '\\')))
		*ptr++ = *p++;
	*ptr = 0;
	if (*p)
		p += 1;
	ret = STRING;
    } else if (*p=='[') {
	while (*p && *p!=']')
		p++;
	if (*p)
		p++;
	linelim = p-line;
	return yylex();
    } else ret = *p++;
    linelim = p-line;
    return ret;
}


/*
 * Given a token string starting with a symbolic column name and its valid
 * length, convert column name ("A"-"Z" or "AA"-"ZZ") to a column number (0-N).
 * Never mind if the column number is illegal (too high).  The procedure's name
 * and function are the inverse of coltoa().
 * 
 * Case-insensitivity is done crudely, by ignoring the 040 bit.
 */

int
atocol (string, len)
	char	*string;
	int	len;
{
	register int col;

	col = (string [0] & 0137) - 'A';

	if (len == 2)		/* has second char */
	    col = ((col + 1) * 26) + ((string [1] & 0137) - 'A');

	return (col);
}


#ifdef SIMPLE

void
initkbd()
{}

void
kbd_again()
{}

void
resetkbd()
{}

#ifndef VMS

int
nmgetch()
{
    return (toascii(getchar()));
}

#else /* VMS */

int
nmgetch()
/*
   This is not perfect, it doesn't move the cursor when goraw changes
   over to deraw, but it works well enough since the whole sc package
   is incredibly stable (loop constantly positions cursor).

   Question, why didn't the VMS people just implement cbreak?

   NOTE: During testing it was discovered that the DEBUGGER and curses
   and this method of reading would collide (the screen was not updated
   when continuing from screen mode in the debugger).
*/
{
    short c;
    static int key_id=0;
    int status;
#define VMScheck(a) {if (~(status = (a)) & 1) VMS_MSG (status);}

    if (VMS_read_raw) {
      VMScheck(smg$read_keystroke (&stdkb->_id, &c, 0, 0, 0));
    }
    else
       c = getchar();

    switch (c) {
    case SMG$K_TRM_LEFT:  c = ctl('b'); break;
    case SMG$K_TRM_RIGHT: c = ctl('f'); break;
    case SMG$K_TRM_UP:    c = ctl('p'); break;
    case SMG$K_TRM_DOWN:  c = ctl('n'); break;
    default:   c = c & A_CHARTEXT;
    }
    return (c);
}


VMS_MSG (status)
int status;
/*
   Routine to put out the VMS operating system error (if one occurs).
*/
{
#include <descrip.h>
   char errstr[81], buf[120];
   $DESCRIPTOR(errdesc, errstr);
   short int length;
#define err_out(msg) fprintf (stderr,msg)

/* Check for no error or standard error */

   if (~status & 1) {
      status = status & 0x8000 ? status & 0xFFFFFFF : status & 0xFFFF;
      if (SYS$GETMSG(status, &length, &errdesc, 1, 0) == SS$_NORMAL) {
	 errstr[length] = '\0';
	 (void) sprintf (buf, "<0x%x> %s", status, errdesc.dsc$a_pointer);
	 err_out (buf);
      }
      else
         err_out ("System error");
   }
}
#endif /* VMS */

#else /*SIMPLE*/

#if defined(BSD42) || defined (SYSIII) || defined(BSD43)

#define N_KEY 4

struct key_map {
    char *k_str;
    char k_val;
    char k_index;
}; 

struct key_map km[N_KEY];

char keyarea[N_KEY*30];

char *tgetstr();
char *getenv();
char *ks;
char ks_buf[20];
char *ke;
char ke_buf[20];

#ifdef TIOCSLTC
struct ltchars old_chars, new_chars;
#endif

char dont_use[] = {
	ctl('['), ctl('a'), ctl('b'), ctl('c'), ctl('e'), ctl('f'), ctl('g'), ctl('h'),
	ctl('i'), ctl('j'),  ctl('l'), ctl('m'), ctl('n'), ctl('p'), ctl('q'),
	ctl('r'), ctl('s'), ctl('t'), ctl('u'), ctl('v'),  ctl('w'), ctl('x'),
	ctl('z'), 0
};

void
charout(c)
int c;
{
	(void)putchar(c);
}

void
initkbd()
{
    register struct key_map *kp;
    register i,j;
    char *p = keyarea;
    char *ktmp;
    static char buf[1024]; /* Why do I have to do this again? */

    if (!(ktmp = getenv("TERM"))) {
	(void) fprintf(stderr, "TERM environment variable not set\n");
	exit (1);
    }
    if (tgetent(buf, ktmp) <= 0)
	return;

    km[0].k_str = tgetstr("kl", &p); km[0].k_val = ctl('b');
    km[1].k_str = tgetstr("kr", &p); km[1].k_val = ctl('f');
    km[2].k_str = tgetstr("ku", &p); km[2].k_val = ctl('p');
    km[3].k_str = tgetstr("kd", &p); km[3].k_val = ctl('n');

    ktmp = tgetstr("ks",&p);
    if (ktmp)  {
	(void) strcpy(ks_buf, ktmp);
	ks = ks_buf;
	tputs(ks, 1, charout);
    }
    ktmp = tgetstr("ke",&p);
    if (ktmp)  {
	(void) strcpy(ke_buf, ktmp);
	ke = ke_buf;
    }

    /* Unmap arrow keys which conflict with our ctl keys   */
    /* Ignore unset, longer than length 1, and 1-1 mapped keys */

    for (i = 0; i < N_KEY; i++) {
	kp = &km[i];
	if (kp->k_str && (kp->k_str[1] == 0) && (kp->k_str[0] != kp->k_val))
	    for (j = 0; dont_use[j] != 0; j++)
	        if (kp->k_str[0] == dont_use[j]) {
		     kp->k_str = (char *)0;
		     break;
		}
    }


#ifdef TIOCSLTC
    (void)ioctl(fileno(stdin), TIOCGLTC, (char *)&old_chars);
    new_chars = old_chars;
    if (old_chars.t_lnextc == ctl('v'))
	new_chars.t_lnextc = -1;
    if (old_chars.t_rprntc == ctl('r'))
	new_chars.t_rprntc = -1;
    (void)ioctl(fileno(stdin), TIOCSLTC, (char *)&new_chars);
#endif
}

void
kbd_again()
{
    if (ks) 
	tputs(ks, 1, charout);

#ifdef TIOCSLTC
    (void)ioctl(fileno(stdin), TIOCSLTC, (char *)&new_chars);
#endif
}

void
resetkbd()
{
    if (ke) 
	tputs(ke, 1, charout);

#ifdef TIOCSLTC
    (void)ioctl(fileno(stdin), TIOCSLTC, (char *)&old_chars);
#endif
}

int
nmgetch() 
{
    register int c;
    register struct key_map *kp;
    register struct key_map *biggest;
    register int i;
    int almost;
    int maybe;

    static char dumpbuf[10];
    static char *dumpindex;

#ifdef SIGVOID
    void time_out();
#else
    int time_out();
#endif

    if (dumpindex && *dumpindex)
	    return (*dumpindex++);

    c = toascii(getchar());
    biggest = 0;
    almost = 0;

    for (kp = &km[0]; kp < &km[N_KEY]; kp++) {
	if (!kp->k_str)
	    continue;
	if (c == kp->k_str[kp->k_index]) {
	    almost = 1;
	    kp->k_index++;
	    if (kp->k_str[kp->k_index] == 0) {
		c = kp->k_val;
	        for (kp = &km[0]; kp < &km[N_KEY]; kp++)
	            kp->k_index = 0;
	        return(c);
	    }
	}
	if (!biggest && kp->k_index)
	    biggest = kp;
        else if (kp->k_index && biggest->k_index < kp->k_index)
	    biggest = kp;
    }

    if (almost) { 
        (void) signal(SIGALRM, time_out);
        (void) alarm(1);

	if (setjmp(wakeup) == 0) { 
	    maybe = nmgetch();
	    (void) alarm(0);
	    return(maybe);
	}
    }
    
    if (biggest) {
	for (i = 0; i<biggest->k_index; i++) 
	    dumpbuf[i] = biggest->k_str[i];
	if (!almost)
	    dumpbuf[i++] = c;
	dumpbuf[i] = '\0';
	dumpindex = &dumpbuf[1];
	for (kp = &km[0]; kp < &km[N_KEY]; kp++)
	    kp->k_index = 0;
	return (dumpbuf[0]);
    }

    return(c);
}

#endif

#if defined(SYSV2) || defined(SYSV3) || defined(MSDOS)

void
initkbd()
{
    keypad(stdscr, TRUE);
    notimeout(stdscr,TRUE);
}

void
kbd_again()
{
    keypad(stdscr, TRUE);
    notimeout(stdscr,TRUE);
}

void
resetkbd()
{
    keypad(stdscr, FALSE);
    notimeout(stdscr, FALSE);
}

int
nmgetch()
{
    register int c;

    c = wgetch(stdscr);
    switch (c) {
#ifdef KEY_LEFT
    case KEY_LEFT:  c = ctl('b'); break;
#endif
#ifdef KEY_RIGHT
    case KEY_RIGHT: c = ctl('f'); break;
#endif
#ifdef KEY_UP
    case KEY_UP:    c = ctl('p'); break;
#endif
#ifdef KEY_DOWN
    case KEY_DOWN:  c = ctl('n'); break;
#endif
#ifdef KEY_BACKSPACE
    case KEY_BACKSPACE:  c = ctl('h'); break;
#endif
#ifdef KEY_NPAGE
    case KEY_NPAGE:	break;
#endif
#ifdef KEY_PPAGE
    case KEY_PPAGE:	break;
#endif
#ifdef KEY_HOME
    case KEY_HOME:	break;
#endif
#ifdef KEY_DC
    case KEY_DC:    c = 'x'; break;
#endif
#ifdef KEY_FIND
    case KEY_FIND:  c = 'g'; break;
#endif
#ifdef KEY_HELP
    case KEY_HELP:  c = '?'; break;
#endif
#ifdef KEY_SELECT
    case KEY_SELECT:c = 'm'; break;
#endif
#ifdef KEY_C1
/* This stuff works for a wyse wy75 in ANSI mode under 5.3.  Good luck. */
/* It is supposed to map the curses keypad back to the numeric equiv. */
    case KEY_C1:    c = '0'; break;
    case KEY_A1:    c = '1'; break;
    case KEY_B2:    c = '2'; break;
    case KEY_A3:    c = '3'; break;
    case KEY_F(5):  c = '4'; break;
    case KEY_F(6):  c = '5'; break;
    case KEY_F(7):  c = '6'; break;
    case KEY_F(9):  c = '7'; break;
    case KEY_F(10): c = '8'; break;
    case KEY_F0:    c = '9'; break;
    case KEY_C3:    c = '.'; break;
    case KEY_ENTER: c = ctl('m'); break;
#endif
    default:        c = toascii(c); 
    break;
    }
    return (c);
}

#endif /* SYSV2 || SYSV3 */

#endif /* SIMPLE */

#ifdef SIGVOID
void
#else
int
#endif
time_out(signo)
int signo;
{
    longjmp(wakeup, 1);
}

/*
 * This converts a floating point number of the form
 * [s]ddd[.d*][esd*]  where s can be a + or - and e is E or e.
 * to floating point. 
 * p is advanced.
 */

char *
strtof(p, res)
register char *p;
double *res;
{
    double acc;
    int sign;
    double fpos;
    int exp;
    int exps;
#ifdef SIGVOID
    void (*sig_save)();
#else
    int (*sig_save)();
#endif
    sig_save = signal(SIGFPE, fpe_trap);
    if (setjmp(fpe_buf)) {
	error("Floating point exception\n");
	*res = 0.0; 
        (void) signal(SIGFPE, sig_save);
	return(p);
    }
    acc = 0.0;
    sign = 1;
    exp = 0;
    exps = 1;
    if (*p == '+')
        p++;
    else if (*p == '-') {
        p++;
        sign = -1;
    }
    while (isdigit(*p)) {
        acc = acc * 10.0 + (double)(*p - '0');
        p++;
    }
    if (*p == 'e' || *p == 'E') {
	    p++;
        if (*p == '+')
	    p++;
        else if (*p == '-') {
	    p++;
	    exps = -1;
        }
        while(isdigit(*p)) {
	    exp = exp * 10 + (*p - '0');
	    p++;
        }
    }
    if (*p == '.') {
	fpos = 1.0/10.0;
	p++;
	while(isdigit(*p)) {
	    acc += (*p - '0') * fpos;
	    fpos *= 1.0/10.0;
	    p++;
	}
    }
    if (*p == 'e' || *p == 'E') {
	exp = 0;
	exps = 1;
        p++;
	if (*p == '+')
	    p++;
	else if (*p == '-') {
	    p++;
	    exps = -1;
	}
	while(isdigit(*p)) {
	    exp = exp * 10 + (*p - '0');
	    p++;
	}
    }
    if (exp) {
	if (exps > 0)
	    while (exp--)
		acc *= 10.0;
	else
	    while (exp--)
		acc *= 1.0/10.0;
    }
    if (sign > 0)
        *res = acc;
    else
	*res = -acc;

    (void) signal(SIGFPE, sig_save);
    return(p);
}