How to use ply - 10 common examples
To help you get started, we’ve selected a few ply examples, based on popular ways it is used in public projects.
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dabeaz / ply / test / lex_state_try.py View on Github 
def t_comment_body_part(t):
r'(.|\n)*\*/'
print("comment body %s" % t)
t.lexer.begin('INITIAL')
def t_error(t):
pass
t_comment_error = t_error
t_comment_ignore = t_ignore
lex.lex()
data = "3 + 4 /* This is a comment */ + 10"
lex.runmain(data=data)def p_expression_number(t):
'expression : NUMBER'
t[0] = t[1]
def p_expression_name(t):
'expression : NAME'
try:
t[0] = names[t[1]]
except LookupError:
print("Undefined name '%s'" % t[1])
t[0] = 0
def p_error(t):
print("Syntax error at '%s'" % t.value)
parser = yacc.yacc()
import calclex
calclex.lexer.lineno=1
parser.parse("""
a = 3 +
(4*5) +
(a b c) +
+ 6 + 7
""", tracking=True)def p_expression_number(t):
'expression : NUMBER'
t[0] = t[1]
def p_expression_name(t):
'expression : NAME'
try:
t[0] = names[t[1]]
except LookupError:
print("Undefined name '%s'" % t[1])
t[0] = 0
def p_error(t):
print("Syntax error at '%s'" % t.value)
yacc.yacc()def build_lexer(self, **kwargs):
self.lexer = lex.lex(module=self, **kwargs)tokens = [
"PLUS",
"MINUS",
"-",
"NUMBER",
]
t_PLUS = r'\+'
t_MINUS = r'-'
t_NUMBER = r'\d+'
def t_error(t):
pass
lex.lex()def p_expression_number(t):
'expression : NUMBER'
t[0] = t[1]
def p_expression_name(t):
'expression : NAME'
try:
t[0] = names[t[1]]
except LookupError:
print("Undefined name '%s'" % t[1])
t[0] = 0
def p_error(t):
print("Syntax error at '%s'" % t.value)
yacc.yacc()t.value = 0
return t
t_ignore = " \t"
def t_newline(t):
r'\n+'
t.lineno += t.value.count("\n")
def t_error(t):
print("Illegal character '%s'" % t.value[0])
t.lexer.skip(1)
# Build the lexer
lex.lex(optimize=1)
lex.runmain(data="3+4")t.value = 0
return t
t_ignore = " \t"
def t_newline(t):
r'\n+'
t.lineno += t.value.count("\n")
def t_error(t):
print("Illegal character '%s'" % t.value[0])
t.lexer.skip(1)
# Build the lexer
lex.lex(optimize=1,lextab="lexdir.sub.calctab" ,outputdir="lexdir/sub")
lex.runmain(data="3+4")def p_error(p):
if p:
print("Line %d: Syntax error at '%s'" % (p.lineno, p.value))
# Scan ahead looking for a name token
while True:
tok = yacc.token()
if not tok or tok.type == 'RPAREN':
break
if tok:
yacc.restart()
return Nonedef test_lex_token5(self):
try:
run_import("lex_token5")
except ply.lex.LexError:
e = sys.exc_info()[1]
self.assert_(check_expected(str(e),"lex_token5.py:19: Rule 't_NUMBER' returned an unknown token type 'NUM'"))
