rubysolo/dentaku — pull request #34 by schneidmaster (2014-12-17 16:47:56+00:00)
Title: Fix recognition of unary minus operator.

Current behavior does not correctly apply precedence to the unary minus operator:

c = Dentaku::Calculator.new
c.evaluate('-4 + 3')
#=> -7

Added an optional minus before numeric tokens as well as specs to confirm.