If 1 or more plus/minus op exist, evaluate the plus/minus symbol in parsing stage #60

[daeisbae]

Changes

• Two or more plus/minus symbol before the Expression will be evaluated in parsing stage. ( -1 * -1 = +1, -1 * +1 = -1, +1 * +1 = +1) #60

Demo

 ./AParser                                                                                                                               ─╯
>>> +1 ----1
2
>>> -----11 ++---++--1
-12
>>> 1--1
2
>>> 1+-----1
0