No I think Python's struct module is also really bad. My point is if you are making a new DSL for laying out arbitrary formats why not do something better than what we have
And, as a bonus, creating, say, a filesystem implementation is now often as easy as copy/pasting existing C structure definitions, either from the original source (which is usually C) or from reversing tools such as IDA/Ghidra.
There’s no right or wrong way in my opinion, just preferences.
C structs seem less bad than python structs, so why not use them? Especially why write a struct parser and create a DSL for it, when there's already one that you can use that uses a well known DSL you might already understand.
The library used in the author's post seems perfectly readable to me, enough that it didn't even register until I read your comment. Could it be tweaked slightly to not use C syntax? Sure, but it's still going to need roughly the same pattern of identifier + type (including size). Types in C are straightforward so long as you don't have functions/pointers (which have the "inside out" problem, but they're not needed for binary encodings), so you're going to be looking at pretty trivial changes to syntax. Certainly not enough to warrant this level of quibbling.
from parser import struct, packed, array, u8, u32, u64
@struct(packed)
class ASIF:
magic: array[u8, 4]
field4: u32
field8: u32
fieldC: u32
field10: u64
field18: u64
field20: array[u8, 16]
field30: u64
field38: u64
field40: u32
field44: u32
field48: u32
field4C: u32
let asif = ASIF.from_bytes(...)
print(asif.fieldC)I still think it proves my point: your original objection was about the syntax being C-like and, as I predicted, the differences in syntax in your idea (where the type goes, colon vs positional, etc.) are all trivialities that don't affect usability.
What's better about your idea is that it's actual Python code rather than being embedded in a string. Maybe that was your point originally and I misunderstood.
Looks like this package works like this: https://harrymander.xyz/dataclasses-struct/