--- ray/src/common/calexpr.c	1990/08/18 16:28:52	1.7
+++ ray/src/common/calexpr.c	1992/05/19 20:21:58	2.5
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -27,15 +27,15 @@ static char SCCSid[] = "$SunId$ LBL";
 #include  "calcomp.h"
 
 #define  MAXLINE	256		/* maximum line length */
-#define  MAXWORD	64		/* maximum word length */
 
 #define  newnode()	(EPNODE *)ecalloc(1, sizeof(EPNODE))
 
-#define  isid(c)	(isalnum(c) || (c) == '_' || (c) == '.')
-
 #define  isdecimal(c)	(isdigit(c) || (c) == '.')
 
-extern double  atof(), pow();
+#ifndef atof
+extern double  atof();
+#endif
+extern double  pow();
 extern char  *fgets(), *savestr();
 extern char  *emalloc(), *ecalloc();
 extern EPNODE  *curfunc;
@@ -78,8 +78,10 @@ double  (*eoper[])() = {		/* expression operations */
 	esubtr,
 	0,
 	edivi,
-	0,0,0,0,0,0,0,0,0,0,0,0,0,
+	0,0,0,0,0,0,0,0,0,0,
 	ebotch,
+	0,0,
+	ebotch,
 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 	epow,
@@ -134,11 +136,11 @@ register EPNODE  *epar;
 	case VAR:
 	    varfree(epar->v.ln);
 	    break;
-#endif
 	    
 	case SYM:
 	    freestr(epar->v.name);
 	    break;
+#endif
 
 	case NUM:
 	case CHAN:
@@ -324,8 +326,24 @@ int  ln;
 }
 
 
-scan()				/* scan next character */
+getscanpos(fnp, lnp, spp, fpp)	/* return current scan position */
+char  **fnp;
+int  *lnp;
+char  **spp;
+FILE  **fpp;
 {
+    if (fnp != NULL) *fnp = infile;
+    if (lnp != NULL) *lnp = lineno;
+    if (spp != NULL) *spp = linbuf+linepos;
+    if (fpp != NULL) *fpp = infp;
+}
+
+
+int
+scan()				/* scan next character, return literal next */
+{
+    register int  lnext = 0;
+
     do {
 	if (linbuf[linepos] == '\0')
 	    if (infp == NULL || fgets(linbuf, MAXLINE, infp) == NULL)
@@ -337,6 +355,8 @@ scan()				/* scan next character */
 	    }
 	else
 	    nextc = linbuf[linepos++];
+	if (!lnext)
+		lnext = nextc;
 	if (nextc == '{') {
 	    scan();
 	    while (nextc != '}')
@@ -347,6 +367,7 @@ scan()				/* scan next character */
 	    scan();
 	}
     } while (isspace(nextc));
+    return(lnext);
 }
 
 
@@ -416,29 +437,35 @@ EPNODE  *ekid;
 }
 
 
+#if  defined(VARIABLE) || defined(FUNCTION)
 char *
 getname()			/* scan an identifier */
 {
     static char  str[MAXWORD+1];
-    register int  i;
+    register int  i, lnext;
 
-    for (i = 0; i < MAXWORD && isid(nextc); i++, scan())
-	str[i] = nextc;
+    lnext = nextc;
+    for (i = 0; i < MAXWORD && isid(lnext); i++, lnext = scan())
+	str[i] = lnext;
     str[i] = '\0';
+    while (isid(lnext))		/* skip rest of name */
+	lnext = scan();
 
     return(str);
 }
+#endif
 
 
 int
 getinum()			/* scan a positive integer */
 {
-    register int  n;
+    register int  n, lnext;
 
     n = 0;
-    while (isdigit(nextc)) {
-	n = n * 10 + nextc - '0';
-	scan();
+    lnext = nextc;
+    while (isdigit(lnext)) {
+	n = n * 10 + lnext - '0';
+	lnext = scan();
     }
     return(n);
 }
@@ -447,32 +474,33 @@ getinum()			/* scan a positive integer */
 double
 getnum()			/* scan a positive float */
 {
-    register int  i;
+    register int  i, lnext;
     char  str[MAXWORD+1];
 
     i = 0;
-    while (isdigit(nextc) && i < MAXWORD) {
-	str[i++] = nextc;
-	scan();
+    lnext = nextc;
+    while (isdigit(lnext) && i < MAXWORD) {
+	str[i++] = lnext;
+	lnext = scan();
     }
-    if (nextc == '.' && i < MAXWORD) {
-    	str[i++] = nextc;
-    	scan();
-	while (isdigit(nextc) && i < MAXWORD) {
-	    str[i++] = nextc;
-	    scan();
+    if (lnext == '.' && i < MAXWORD) {
+    	str[i++] = lnext;
+    	lnext = scan();
+	while (isdigit(lnext) && i < MAXWORD) {
+	    str[i++] = lnext;
+	    lnext = scan();
 	}
     }
-    if ((nextc == 'e' || nextc == 'E') && i < MAXWORD) {
-    	str[i++] = nextc;
-    	scan();
-	if ((nextc == '-' || nextc == '+') && i < MAXWORD) {
-	    str[i++] = nextc;
-	    scan();
+    if ((lnext == 'e' || lnext == 'E') && i < MAXWORD) {
+    	str[i++] = lnext;
+    	lnext = scan();
+	if ((lnext == '-' || lnext == '+') && i < MAXWORD) {
+	    str[i++] = lnext;
+	    lnext = scan();
 	}
-	while (isdigit(nextc) && i < MAXWORD) {
-	    str[i++] = nextc;
-	    scan();
+	while (isdigit(lnext) && i < MAXWORD) {
+	    str[i++] = lnext;
+	    lnext = scan();
 	}
     }
     str[i] = '\0';
@@ -528,23 +556,23 @@ getE2()				/* E2 -> E2 MULOP E3 */
 
 
 EPNODE *
-getE3()				/* E3 -> E3 ^ E4 */
+getE3()				/* E3 -> E4 ^ E3 */
 				/*       E4 */
 {
     register EPNODE  *ep1, *ep2;
 
     ep1 = getE4();
-    while (nextc == '^') {
+    if (nextc == '^') {
 	ep2 = newnode();
 	ep2->type = nextc;
 	scan();
 	addekid(ep2, ep1);
-	addekid(ep2, getE4());
+	addekid(ep2, getE3());
 #ifdef  RCONST
 	if (ep1->type == NUM && ep1->sibling->type == NUM)
 		ep2 = rconst(ep2);
 #endif
-	ep1 = ep2;
+	return(ep2);
     }
     return(ep1);
 }
@@ -563,6 +591,10 @@ getE4()				/* E4 -> ADDOP E5 */
 		ep2->v.num = -ep2->v.num;
 		return(ep2);
 	}
+	if (ep2->type == UMINUS) {	/* don't generate -(-E5) */
+	    efree((char *)ep2);
+	    return(ep2->v.kid);
+	}
 	ep1 = newnode();
 	ep1->type = UMINUS;
 	addekid(ep1, ep2);
@@ -583,6 +615,7 @@ getE5()				/* E5 -> (E1) */
 				/*       ARG */
 {
     int  i;
+    char  *nam;
     register EPNODE  *ep1, *ep2;
 
     if (nextc == '(') {
@@ -605,23 +638,26 @@ getE5()				/* E5 -> (E1) */
 #endif
 
 #if  defined(VARIABLE) || defined(FUNCTION)
-    if (isalpha(nextc)) {
-	ep1 = newnode();
-	ep1->type = VAR;
-	ep1->v.ln = varinsert(getname());
-
+    if (isalpha(nextc) || nextc == CNTXMARK) {
+	nam = getname();
 #if  defined(VARIABLE) && defined(FUNCTION)
+	ep1 = NULL;
 	if (curfunc != NULL)
 	    for (i = 1, ep2 = curfunc->v.kid->sibling;
 	    			ep2 != NULL; i++, ep2 = ep2->sibling)
-		if (!strcmp(ep2->v.name, ep1->v.ln->name)) {
-		    epfree(ep1);
+		if (!strcmp(ep2->v.name, nam)) {
 		    ep1 = newnode();
 		    ep1->type = ARG;
 		    ep1->v.chan = i;
 		    break;
 		}
+	if (ep1 == NULL)
 #endif
+	{
+	    ep1 = newnode();
+	    ep1->type = VAR;
+	    ep1->v.ln = varinsert(nam);
+	}
 #ifdef  FUNCTION
 	if (nextc == '(') {
 	    ep2 = newnode();
@@ -641,6 +677,10 @@ getE5()				/* E5 -> (E1) */
 	    syntax("'(' expected");
 #endif
 #endif
+#ifdef  RCONST
+	if (isconstvar(ep1))
+	    ep1 = rconst(ep1);
+#endif
 	return(ep1);
     }
 #endif
@@ -672,4 +712,54 @@ register EPNODE  *epar;
  
     return(ep);
 }
+
+
+isconstvar(ep)			/* is ep linked to a constant expression? */
+register EPNODE  *ep;
+{
+#ifdef  VARIABLE
+    register EPNODE  *ep1;
+#ifdef  FUNCTION
+
+    if (ep->type == FUNC) {
+	if (!isconstfun(ep->v.kid))
+		return(0);
+	for (ep1 = ep->v.kid->sibling; ep1 != NULL; ep1 = ep1->sibling)
+	    if (ep1->type != NUM && !isconstfun(ep1))
+		return(0);
+	return(1);
+    }
+#endif
+    if (ep->type != VAR)
+	return(0);
+    ep1 = ep->v.ln->def;
+    if (ep1 == NULL || ep1->type != ':')
+	return(0);
+#ifdef  FUNCTION
+    if (ep1->v.kid->type != SYM)
+	return(0);
+#endif
+    return(1);
+#else
+    return(ep->type == FUNC);
+#endif
+}
+
+
+#if  defined(FUNCTION) && defined(VARIABLE)
+isconstfun(ep)			/* is ep linked to a constant function? */
+register EPNODE  *ep;
+{
+    register EPNODE  *dp;
+    register LIBR  *lp;
+
+    if (ep->type != VAR)
+	return(0);
+    if ((dp = ep->v.ln->def) != NULL && dp->v.kid->type == FUNC)
+	return(dp->type == ':');
+    if ((lp = ep->v.ln->lib) != NULL)
+	return(lp->atyp == ':');
+    return(0);
+}
+#endif
 #endif