It’s possible. I wrote a tool years ago to scan a file for C++ enum
syntax using pyparsing. It’s now a pyparsing example that I’ve reproduced here in case the link changes. As you can see the file doesn’t have to even be entirely valid C++. It defines the enum
grammar and scans the file for text matching the grammar, generating Python variables.
#
# cpp_enum_parser.py
#
# Posted by Mark Tolonen on comp.lang.python in August, 2009,
# Used with permission.
#
# Parser that scans through C or C++ code for enum definitions, and
# generates corresponding Python constant definitions.
#
#
from pyparsing import *
# sample string with enums and other stuff
sample = """
stuff before
enum hello {
Zero,
One,
Two,
Three,
Five=5,
Six,
Ten=10
};
in the middle
enum blah
{
alpha,
beta,
gamma = 10 ,
zeta = 50
};
at the end
"""
# syntax we don't want to see in the final parse tree
LBRACE, RBRACE, EQ, COMMA = map(Suppress, "{}=,")
_enum = Suppress("enum")
identifier = Word(alphas, alphanums + "_")
integer = Word(nums)
enumValue = Group(identifier("name") + Optional(EQ + integer("value")))
enumList = Group(enumValue + ZeroOrMore(COMMA + enumValue))
enum = _enum + identifier("enum") + LBRACE + enumList("names") + RBRACE
# find instances of enums ignoring other syntax
for item, start, stop in enum.scanString(sample):
id = 0
for entry in item.names:
if entry.value != "":
id = int(entry.value)
print("%s_%s = %d" % (item.enum.upper(), entry.name.upper(), id))
id += 1
Output:
HELLO_ZERO = 0
HELLO_ONE = 1
HELLO_TWO = 2
HELLO_THREE = 3
HELLO_FIVE = 5
HELLO_SIX = 6
HELLO_TEN = 10
BLAH_ALPHA = 0
BLAH_BETA = 1
BLAH_GAMMA = 10
BLAH_ZETA = 50