/* xlisp - a small subset of lisp */

#include <stdio.h>
/* #include <setjmp.h> */
#include "xlisp.h"

/* global variables */
/* jmp_buf xljmpbuf; */

/* external variables */
extern struct node *xlenv;
extern struct node *xlstack;
extern int xlpvals;

/* Read file, if it exists */
static int xlfget(mylib)
char	*mylib;
{
	FILE *xf;

	/* Try opening the file */
	if((xf = fopen(mylib, "r")) != 0)
	{
		fclose(xf);
		xlfin(mylib);
		return(TRUE);
	}

	return(FALSE);
}


/* main - the main routine */
main(argc,argv)
  int argc; char *argv[];
{
    struct node expr;

    /* initialize the dynamic memory module (must be first) */
    xldmeminit();

    /* initialize xlisp */
    xlinit();  xleinit(); xllinit(); xlminit();
    xlsinit(); xlfinit(); xlpinit(); xlhinit();

    /* initialize terminal input */
    xltin(FALSE);

    /* read the input file if specified */
    if (argc > 1)
	xlfin(argv[1]);
    else
	if((
		/* Read system file, if accessible */
		xlfget("SY:[1,1]MINI.LSP")	|

		/* Read user file, if accessible */
		xlfget("MINI.LSP")
	) == FALSE)

	printf("\nMiniLISP 1.0\n");

    /* main command processing loop */
    while (TRUE) {

	/* setup the error return */
	/* setjmp(xljmpbuf);	*/	/* Jan Brittenson UFH 11-Oct-86 */

#ifdef decusc
	setexit();
#endif

	/* free any previous expression and leftover context */
	xlstack = xlenv = NULL;

	/* create a new stack frame */
	xlsave(&expr,NULL);

	/* read an expression */
	expr.n_ptr = xlread();

	/* evaluate the expression */
	expr.n_ptr = xleval(expr.n_ptr);

	/* print it if necessary */
	if (xlpvals) {
	    xlprint(expr.n_ptr,TRUE);
	    putchar('\n');
	}
    }
}