grammar Robot;

/* This will be the entry point of our parser. */
eval:    controlExp;

controlExp: (move | turn)* | off;

move   : 'move' additionExp;
turn   : 'turn' additionExp;
off    : 'off';

additionExp:    left=multiplyExp ( ('+'|'-') multiplyExp)*;

multiplyExp:    left=partial ( ('*'|'/') partial)*;

partial:    number=Number | addition='(' additionExp ')';

Number:    ('0'..'9')+;

WS : [ \t\r\n]+ -> skip ; // skip spaces, tabs, newlines