// Get a statement
numvar getstatement(void) {
numvar retval = 0;
//char *fetchmark;
numvar fetchmark;

	chkbreak();

	if (sym == s_while) {
		// at this point sym is pointing at s_while, before the conditional expression
		// save fetchptr so we can restart parsing from here as the while iterates
		//fetchmark = fetchptr;
		fetchmark = markparsepoint();
		for (;;) {
			//fetchptr = fetchmark;			// restore to mark
			//primec();						// set up for mr. getsym()
			returntoparsepoint(fetchmark, 0);
			getsym(); 						// fetch the start of the conditional
			if (getnum()) {
				retval = getstatement();
				if (sym == s_returning) break;	// exit if we caught a return
			}
			else {
				skipstatement();
				break;
			}
		}
	}
	
	else if (sym == s_if) {
		getsym();			// eat "if"
		if (getnum()) {
			retval = getstatement();
			if (sym == s_else) {
				getsym();	// eat "else"
				skipstatement();
			}
		} else {
			skipstatement();
			if (sym == s_else) {
				getsym();	// eat "else"
				retval = getstatement();
			}
		}
	}
	else if (sym == s_lcurly) {
		getsym(); 	// eat "{"
		while ((sym != s_eof) && (sym != s_returning) && (sym != s_rcurly)) retval = getstatement();
		if (sym == s_rcurly) getsym();	// eat "}"
	}
	else if (sym == s_return) {
		getsym();	// eat "return"
		if ((sym != s_eof) && (sym != s_semi)) retval = getnum();
		sym = s_returning;		// signal we're returning up the line
	}
	else if (sym == s_switch) retval = getswitchstatement();

	else if (sym == s_function) cmd_function();

	else if (sym == s_run) {	// run macroname
		getsym();
		if ((sym != s_script_eeprom) && (sym != s_script_progmem) &&
			(sym != s_script_file)) unexpected(M_id);

		// address of macroid is in symval via parseid
		// check for [,snoozeintervalms]
		getsym();	// eat macroid to check for comma; symval untouched
		if (sym == s_comma) {
			vpush(symval);
			getsym();			// eat the comma
			getnum();			// get a number or else
			startTask(vpop(), expval);
		}
		else startTask(symval, 0);
	}

	else if (sym == s_stop) {
		getsym();
		if (sym == s_mul) {						// stop * stops all tasks
			initTaskList();
			getsym();
		}
		else if ((sym == s_semi) || (sym == s_eof)) {
			if (background) stopTask(curtask);	// stop with no args stops the current task IF we're in back
			else initTaskList();				// in foreground, stop all
		}
		else stopTask(getnum());
	}

	else if (sym == s_boot) reboot();
	else if (sym == s_rm) {		// rm "sym" or rm *
		getsym();
		if (sym == s_script_eeprom) {
			eraseentry(idbuf);
		} 
		else if (sym == s_mul) nukeeeprom();
		else if (sym != s_undef) expected(M_id);
		getsym();
	}
	else if (sym == s_ps) 		{ getsym();	showTaskList(); }
	else if (sym == s_peep) 	{ getsym(); cmd_peep(); }
	else if (sym == s_ls) 		{ getsym(); cmd_ls(); }
	else if (sym == s_help) 	{ getsym(); cmd_help(); }
	else if (sym == s_print) 	{ getsym(); cmd_print(); }
	else if (sym == s_semi)		{ ; }	// ;)

#ifdef HEX_UPLOAD
	// a line beginning with a colon is treated as a hex record
	// containing data to upload to eeprom
	//
	// TODO: verify checksum
	//
	else if (sym == s_colon) {
		// fetchptr points at the byte count
		byte byteCount = gethex(2);		// 2 bytes byte count
		int addr = gethex(4);			// 4 bytes address
		byte recordType = gethex(2);	// 2 bytes record type; now fetchptr -> data
		if (recordType == 1) reboot();	// reboot on EOF record (01)
		if (recordType != 0) return;	// we only handle the data record (00)
		if (addr == 0) nukeeeprom();	// auto-clear eeprom on write to 0000
		while (byteCount--) eewrite(addr++, gethex(2));		// update the eeprom
		gethex(2);						// discard the checksum
		getsym();						// and re-prime the parser
	}
#endif

	else getexpression();

	if (sym == s_semi) getsym();		// eat trailing ';'
	return retval;
}
예제 #2
0
// Get a statement
numvar getstatement(void) {
numvar retval = 0;
char *fetchmark;

	chkbreak();

//#define LINEMODE
#ifdef LINEMODE
	if (sym == s_while) {
		// at this point sym is pointing at s_while, before the conditional expression
		// save fetchptr so we can restart parsing from here as the while iterates
		char *fetchmark = fetchptr;
		for (;;) {
			fetchptr = fetchmark;			// restore to mark
			primec();						// set up for mr. getsym()
			getsym(); 						// fetch the start of the conditional
			if (!getnum()) {					
				//longjmp(env, X_EXIT);		// get the conditional; exit on false
				sym = s_eof;				// we're finished here.  move along.
				return;
			}
			if (sym != s_colon) expectedchar(':');
			getsym();	// eat :
			getstatementlist();
		}
	}
	else if (sym == s_if) {
		getsym(); 								// fetch the start of the conditional
		if (!getnum()) {
			//longjmp(env, X_EXIT);	// get the conditional; exit on false
			sym = s_eof;
			return;
		}
		if (sym != s_colon) expectedchar(':');
		getsym();	// eat :
		getstatementlist();
	}

	// The switch statement: call one of N macros based on a selector value
	// switch <numval>: macroid1, macroid2,.., macroidN
	// numval < 0: numval = 0
	// numval > N: numval = N

	else if (sym == s_switch) {
		getsym();	// eat "switch"
		numvar selector = getnum();	// evaluate the switch value
		if (selector < 0) selector = 0;
		if (sym != s_colon) expectedchar(':');

		// we sit before the first macroid
		// scan and discard the <selector>'s worth of macro ids 
		// that sit before the one we want
		for (;;) {
			getsym();	// get an id, sets symval to its eeprom addr as a side effect
			if (sym != s_macro) expected (6);		// TODO: define M_macro instead of 6
			getsym();	// eat id, get separator; assume symval is untouched
			if ((sym == s_semi) || (sym == s_eof)) break;	// last case is default so we exit always
			if (sym != s_comma) expectedchar(',');
			if (!selector) break;		// ok, this is the one we want to execute
			selector--;					// one down...
		}

		// call the macro whose addr is squirreled in symval all this time
		// on return, the parser is ready to pick up where we left off
		domacrocall(symval);

		// scan past the rest of the unused switch options, if any
		// TODO: syntax checking for non-chosen options could be made much tighter at the cost of some space
		while ((sym != s_semi) && (sym != s_eof)) getsym();		// scan to end of statement without executing
	}

#else
	// new statement handling
	if (sym == s_while) {
		// at this point sym is pointing at s_while, before the conditional expression
		// save fetchptr so we can restart parsing from here as the while iterates
		fetchmark = fetchptr;
		for (;;) {
			fetchptr = fetchmark;			// restore to mark
			primec();						// set up for mr. getsym()
			getsym(); 						// fetch the start of the conditional
			if (getnum()) {
				retval = getstatement();
				if (sym == s_returning) break;	// exit if we caught a return
			}
			else {
				skipstatement();
				break;
			}
		}
	}
	
	else if (sym == s_if) {
		getsym();			// eat "if"
		if (getnum()) {
			retval = getstatement();
			if (sym == s_else) {
				getsym();	// eat "else"
				skipstatement();
			}
		} else {
			skipstatement();
			if (sym == s_else) {
				getsym();	// eat "else"
				retval = getstatement();
			}
		}
	}
	else if (sym == s_lcurly) {
		getsym(); 	// eat "{"
		while ((sym != s_eof) && (sym != s_returning) && (sym != s_rcurly)) retval = getstatement();
		if (sym == s_rcurly) getsym();	// eat "}"
	}
	else if (sym == s_return) {
		getsym();	// eat "return"
		if ((sym != s_eof) && (sym != s_semi)) retval = getnum();
		sym = s_returning;		// signal we're returning up the line
	}
	else if (sym == s_switch) retval = getswitchstatement();

	else if (sym == s_function) cmd_function();

#endif


	else if (sym == s_run) {	// run macroname
		getsym();
		if (sym != s_macro) unexpected(M_id);

		// address of macroid is in symval via parseid
		// check for [,snoozeintervalms]
		getsym();	// eat macroid to check for comma; symval untouched
		if (sym == s_comma) {
			vpush(symval);
			getsym();			// eat the comma
			getnum();			// get a number or else
			startTask(kludge(vpop()), expval);
		}
		else startTask(kludge(symval), 0);
	}

	else if (sym == s_stop) {
		getsym();
		if (sym == s_mul) {						// stop * stops all tasks
			initTaskList();
			getsym();
		}
		else if ((sym == s_semi) || (sym == s_eof)) {
			if (background) stopTask(curtask);	// stop with no args stops the current task IF we're in back
			else initTaskList();				// in foreground, stop all
		}
		else stopTask(getnum());
	}

	else if (sym == s_boot) reboot();

#if !defined(TINY85)
	else if (sym == s_rm) {		// rm "sym" or rm *
		getsym();
		if (sym == s_macro) {
			eraseentry(idbuf);
		} 
		else if (sym == s_mul) nukeeeprom();
		else if (sym != s_undef) expected(M_id);
		getsym();
	}
	else if (sym == s_ps) 		{ getsym();	showTaskList(); }
	else if (sym == s_peep) 	{ getsym(); cmd_peep(); }
	else if (sym == s_ls) 		{ getsym(); cmd_ls(); }
	else if (sym == s_help) 	{ getsym(); cmd_help(); }
	else if (sym == s_print) 	{ getsym(); cmd_print(); }
	else if (sym == s_semi)		{ ; }	// ;)
#endif

#ifdef HEX_UPLOAD
	// a line beginning with a colon is treated as a hex record
	// containing data to upload to eeprom
	//
	// TODO: verify checksum
	//
	else if (sym == s_colon) {
		// fetchptr points at the byte count
		byte byteCount = gethex(2);		// 2 bytes byte count
		int addr = gethex(4);			// 4 bytes address
		byte recordType = gethex(2);	// 2 bytes record type; now fetchptr -> data
		if (recordType == 1) reboot();	// reboot on EOF record (01)
		if (recordType != 0) return;	// we only handle the data record (00)
		if (addr == 0) nukeeeprom();	// auto-clear eeprom on write to 0000
		while (byteCount--) eewrite(addr++, gethex(2));		// update the eeprom
		gethex(2);						// discard the checksum
		getsym();						// and re-prime the parser
	}
#endif

	else getexpression();

	if (sym == s_semi) getsym();		// eat trailing ';'
	return retval;
}