/* Copyright (C) 1995 by Thomas Glen Smith.	All Rights Reserved. */
/* execsper APL2 V1.0.0 ************************************************
* Called by execspex when the form is not a simple (a b c)#d, but is	 *
* e.g. (Er)#x, after setting nametok to the token for r, and p to the  *
* avlnode pointer for r.										 *
***********************************************************************/
#define INCLUDES APLCHDEF+APLDERIV+APLTOKEN+APLCB+TREE
#include "includes.h"
int execsper(p,cbn,nametok)
Avlnode p;		/* Avlnode for r in e.g. (Er)#x. */
Aplcb cbn;		/* (1,2,3,...), reshaped the same as p->avlleaf. */
Apltoken nametok;	/* Token for r in e.g. (Er)#x. */
{
	Execfree; Execgetp; Execinit; Execnext; Execspef; Execterm; Lifo;
	extern Treelist treehdr;
	extern int aplerr;
	Apltoken axistok,op,tok,wrk;
	int	exec_sw=1,hit=0,i,namecnt,noexit,nwa=0,off=0;
	Aplcb cb;
	Treelist treetest;

	treetest = treehdr;
	for (;;) { /* lets me use break */
		cb = p->avlleaf; /* Save original. */
		p->avlleaf = cbn; /* Replace with indices. */
		execinit(); /* push a new execstk element on stack */
		noexit = execnext(&tok,&axistok,&op,&namecnt);
			/* op will be set to one of these 4 possibilities: */
			/* 1) List of names, in which case namecnt will be nonzero. */
			/* 2) OPERAND_TOKEN, in which case further testing must be */
			/*	 done to see if it is selective specification. */
			/* 3) Not an OPERAND_TOKEN, e.g. a function, operator, etc. */
			/*	 It may be selective specification. */
			/* 4) op == NULL, indicating an error. */
		p->avlleaf = cb; /* restore original cb */
		if (aplerr || op == NULL) break;
		off = op->token_offset; /* save offset */
		if (!noexit) { /* Evaluation complete: op s/b selected indices. */
			/* Example: ((,r)[1 3 14 16])#'acde' */
			exec_sw = 0; /* Indicate execterm invoked. */
			execterm();
			op = execspef(nametok,cb,cbn,execgetp(op),nwa); /* Finish. */
			if (op != NULL) {
				hit = 1; /* Indicate specification handled. */
				op = lifo(&(treehdr->avlexec->avloprst),op);
				op = NULL; /* don't free twice */
			}
			break; /* All done. */
		}
		return(execspet(hit,op,nametok,tok,axistok,cb,cbn));
	}
	if (exec_sw) execterm(); /* Call if appropriate. */
	execfree(tok); execfree(axistok); execfree(op);
	return(hit); /* indicate selective specification handled */
}