Fixing the bug preventing usage of custom dumpers

[KOLANICH]

No description provided.

[berkerpeksag]

Could you please give us more information about your use case? It would be even better if you could share a snippet that demonstrates the bug you're trying to fix.

Thank you!

[KOLANICH]

@berkerpeksag,

KaitaiPowerWorkaround.py

from plumbum import cli
from ast import *
import astor  # https://patch-diff.githubusercontent.com/raw/berkerpeksag/astor/pull/151.patch is absolutely needed, as fixes a bug in astor, https://patch-diff.githubusercontent.com/raw/berkerpeksag/astor/pull/152.patch is needed for using hex to make the expr a bit shorter
import typing


class KaitaiGen(astor.SourceGenerator):
	def visit_IfExp(self, node):
		with self.delimit(node) as delimiters:
			astor.code_gen.set_precedence(delimiters.p + 1, node.body, node.test)
			astor.code_gen.set_precedence(delimiters.p, node.orelse)
			self.write("(", node.test, " ? ", node.body, " : ", node.orelse, ")")


def extractPowerOf2(base: int) -> (int, int):
	c = 0
	while base % 2 == 0:
		base //= 2
		c += 1
	return base, c


SGT = typing.Type[KaitaiGen]


def square_and_multiply(base: int, bits: int = 8, argName: str = "log", generator: SGT = None) -> str:
	"""ONLY FOR POSITIVE POWERS!!! Process negative ones yourself."""
	if generator is None:
		generator = KaitaiGen
	baseR, powOf2 = extractPowerOf2(base)

	if powOf2 != 0:
		if powOf2 != 1:
			sh = BinOp(left=Name(id=argName), op=Mult(), right=Num(n=powOf2))
		else:
			sh = Name(id=argName)
		res = BinOp(left=Num(n=1), op=LShift(), right=sh)
	else:
		res = Num(n=1)

	if baseR != 1:
		exp = baseR
		b2Base = 1
		for i in range(bits):
			res = BinOp(
				left=res,
				op=Mult(),
				right=IfExp(
					test=Attribute(
						value=BinOp(
							left=Name(id=argName), op=BitAnd(), right=Num(n=b2Base)
						),
						attr="as<b1>",
					),
					body=Num(n=exp),
					orelse=Num(n=1),
				),
			)
			exp *= exp
			b2Base = b2Base << 1
	return astor.to_source(res, indent_with="", source_generator_class=generator, pretty_source=lambda source: "".join(source)).strip()


class PowerWorkaroundCLI(cli.Application):
	def main(self, base: int, bits: int = 8, argName: str = "log"):
		print("".join("# "+l for l in square_and_multiply.__doc__.splitlines()))
		print('value: "'+square_and_multiply(base, bits, argName)+'"')


if __name__ == "__main__":
	PowerWorkaroundCLI.run()

Please note that the functionality I am fixing in this PR is already present in astor, it is just broken because of a mistake.

[berkerpeksag]

Thank you very much! This has been fixed in 51c9e70.