pycalc_gram.ll

#
# Copyright © 2019 Keith Packard <keithp@keithp.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
#

start	: line start
	|
	;
line	: expr @PRINT@ NL
	| NL
	;
expr	: term expr-p
	;
expr-p	: PLUS term @ADD@ expr-p
	| MINUS term @SUBTRACT@ expr-p
	|
	;
term	: fact term-p
	;
term-p	: TIMES fact @TIMES@ term-p
	| DIVIDE fact @DIVIDE@ term-p
	|
	;
fact	: OP expr CP
	| MINUS fact @NEGATE@
	| NUMBER @PUSH@
	;