Stop argument evaluation

Ignition
1

Is there a way in ignition to stop arguments from being evaluated before entering the method?

For example I want to inspect the argument being sent into test, but when I print it out right now I get the value False instead of something I can parse and inspect.

class Something(object):
	x = "something"

def test(a):
	print a
	
test(Something.x > 5)
2

No. Python doesn't make expressions into objects to pass. (This behavior is not specific to jython, and conforms to pretty much every programming language I know.)

3

Any idea what trickery SqlAlchemy is using? I doubt it is filtering after the dataset is returned. I would think that it is some how making a where clause from the filter methods parameter.

for (name,) in session.query(User.name).filter(User.fullname == "Ed Jones")
4

SQLAlchemy redefines the operators for its classes so that they defer execution. (Strictly speaking, they participate in a framework that outputs SQL to perform the comparison within the DB.) It's mind-numbingly complex. Yes, I've been under that hood.

See the "rich comparison" method signatures here:

https://docs.python.org/2.7/reference/datamodel.html#basic-customization

Essentially, you have your class override those methods to, instead of returning an answer, return an object that remembers the original arguments and knows how to apply that later.

5

Yeah, many things are possible through operator overloading...including making things wildly unreadable and hard to parse. "Domain specific languages", especially inside of other programming languages are often a bad move. 9 times out of 10, avoid them.

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