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# -----------------------------------------------------------------------------
# lex_object.py
# -----------------------------------------------------------------------------
import sys
if ".." not in sys.path: sys.path.insert(0,"..")
import ply.lex as lex
class CalcLexer:
tokens = (
'NAME','NUMBER',
'PLUS','MINUS','TIMES','DIVIDE','EQUALS',
'LPAREN','RPAREN',
)
# Tokens
t_PLUS = r'\+'
t_MINUS = r'-'
t_TIMES = r'\*'
t_DIVIDE = r'/'
t_EQUALS = r'='
t_LPAREN = r'\('
t_RPAREN = r'\)'
t_NAME = r'[a-zA-Z_][a-zA-Z0-9_]*'
def t_NUMBER(self,t):
r'\d+'
try:
t.value = int(t.value)
except ValueError:
print("Integer value too large %s" % t.value)
t.value = 0
return t
t_ignore = " \t"
def t_newline(self,t):
r'\n+'
t.lineno += t.value.count("\n")
def t_error(self,t):
print("Illegal character '%s'" % t.value[0])
t.lexer.skip(1)
calc = CalcLexer()
# Build the lexer
lex.lex(object=calc)
lex.runmain(data="3+4")
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