/* Copyright (C) 1993 by Thomas Glen Smith.  All Rights Reserved. */
/* execalt APL2 V1.0.0 *************************************************
* Quad Execute Alternate.                                              *
***********************************************************************/
#define INCLUDES APLCB+TREE
#include "includes.h"
Aplcb execalt(left,rite)
Aplcb left,rite;
{
	Errinit; Errstop; Executg;
	extern Treelist treehdr;
	extern int aplerr;
	Aplcb out=NULL;

	if (errinit()) return(errstop(0,left,rite,NULL));
	out = executg(rite);
	rite = NULL;
	if (aplerr) {
		aplerr = 0;
		endoper(out);
		errinit();
		out = executg(left);
		left = NULL;
	}
	if (out == NULL) /* Was it niladic? */
		treehdr->lastfun = 2; /* Indicate niladic. */
	return(errstop(0,left,rite,out));
}