16498Snate@binkert.org# lex_re2.py 24479Sbinkertn@umich.edu# 34479Sbinkertn@umich.edu# Regular expression rule matches empty string 44479Sbinkertn@umich.edu 54479Sbinkertn@umich.eduimport sys 66498Snate@binkert.orgif ".." not in sys.path: sys.path.insert(0,"..") 74479Sbinkertn@umich.edu 84479Sbinkertn@umich.eduimport ply.lex as lex 94479Sbinkertn@umich.edu 104479Sbinkertn@umich.edutokens = [ 114479Sbinkertn@umich.edu "PLUS", 124479Sbinkertn@umich.edu "MINUS", 134479Sbinkertn@umich.edu "NUMBER", 144479Sbinkertn@umich.edu ] 154479Sbinkertn@umich.edu 164479Sbinkertn@umich.edut_PLUS = r'\+?' 174479Sbinkertn@umich.edut_MINUS = r'-' 184479Sbinkertn@umich.edut_NUMBER = r'(\d+)' 194479Sbinkertn@umich.edu 204479Sbinkertn@umich.edudef t_error(t): 214479Sbinkertn@umich.edu pass 224479Sbinkertn@umich.edu 236498Snate@binkert.org 244479Sbinkertn@umich.edu 254479Sbinkertn@umich.edulex.lex() 264479Sbinkertn@umich.edu 274479Sbinkertn@umich.edu 28