/*	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: 6.8 $
 *
 */



#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 BSD42
#include <strings.h>
#else
#ifndef SYSIII
#include <string.h>
#endif
#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 */
#include "y.tab.h"
#endif /* VMS */

char *strtof();

jmp_buf wakeup;
jmp_buf fpe_buf;

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

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

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

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)) {
	double v = 0;
	int temp;
	char *nstart = p;
	if (*p != '.') {
	    do v = v*10 + (double)(*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;
		}
	    }
	}
    } else if (*p=='"') {
	char *ptr;
        ptr = p+1;
        while(*ptr && *ptr++ != '"');
        ptr = xmalloc((unsigned)(ptr-p));
	yylval.sval = ptr;
	p += 1;
	while (*p && *p!='"') *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

initkbd()
{}

kbd_again()
{}

resetkbd()
{}

#ifndef VMS

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

#else /* VMS */

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 & 0x7f;
    }
    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';
         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
};

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

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 (tgetent(buf, getenv("TERM")) <= 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
}

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)

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

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

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

nmgetch()
{
    register int c;

    c = getch();
    switch (c) {
    case KEY_LEFT:  c = ctl('b'); break;
    case KEY_RIGHT: c = ctl('f'); break;
    case KEY_UP:    c = ctl('p'); break;
    case KEY_DOWN:  c = ctl('n'); break;
#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
#endif
time_out(signo)
int signo;
{
#ifdef IEEE_MATH
	(void)fpsetsticky((fp_except)0); 		/* Clear exception */
#endif /* IEEE_MATH */
    longjmp(wakeup, -1);
}

#ifdef SIGVOID
void
#endif
fpe_trap(signo)
int signo;
{
    longjmp(fpe_buf, 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);
}