[wbl]

ASN.1 DER, BER, or OER? Implicit and optional can really break compat in surprising ways. Then there are the machine unfriendly roster of available types. XDR was more tuned for that.

Finally free tooling doesn't really exist. The connection to the OSI model also didn't help.

[quotemstr]

> ASN.1 DER, BER, or OER?

Or XER or JER! One of the brilliant things about ASN.1 is that it decouples the data model from the serialization format. Of the major successor systems, only protobuf does something similar, and the text proto format barely counts.

> Implicit and optional can really break compat in surprising ways

Any implementation of any spec can be broken. You could argue that the spec should be simpler and require, e.g., explicit tagging everywhere, like protobuf. Sure. But the complexity enables efficiencies, and it's sometimes worth making a foundational library a bit more complex to enable simplifications and optimizations throughout the ecosystem.

> Then there are the machine unfriendly roster of available type

Protobuf's variable-length integers are machine-friendly now? :-) We can always come up with better encoding rules without changing the fundamental data structures.

> Finally free tooling doesn't really exist.

What do you mean? You use ASN.1 to talk to every server talking SNMP, LDAP, or the X.509 PKI. Every programming environment has a way to talk about ASN.1.

> The connection to the OSI model also didn't help.

Agreed. The legacy string types aren't great either. You can, of course, do ASN.1 better. No technology is perfect. But what we don't need, IMHO, is more investment in "simple" technologies like varlink that end up being too simple and shunting complexity and schema-ness that belongs in a universal foundation layer into every single application using the new "simple" thing.

[zzo38computer]

> ASN.1 DER, BER, or OER? Or XER or JER!

My opinion is that DER is better. (However, DER is a restricted form of BER; any DER file is also a valid BER file, but has certain requirements of the encoding, so that it is a canonical form (the other canonical form is CER, but my opinion is DER is better).)

> Every programming environment has a way to talk about ASN.1.

Not all implementations are well-designed, though; I can see many implementations of ASN.1 that are not well-designed. I made up my own, to hope to be better, but we will see what is (hopefully) better.

> But what we don't need, IMHO, is more investment in "simple" technologies like varlink that end up being too simple

I agree with this, and it is important. This is my intention when I was designing stuff, to not be too simple nor too complicated; most stuff I see tends to be either too complicated or too simple, so I try to make stuff better than that.

[wbl]

There are zero free ASN.1 compilers or module checkers.

[simoncion]

> There are zero free ASN.1 compilers or module checkers.

I must be misunderstanding what you're saying, because this exists: <https://www.erlang.org/doc/apps/asn1/asn1ct.html#>

From the linked page:

> asn1ct

> ASN.1 compiler and compile-time support functions

> The ASN.1 compiler takes an ASN.1 module as input and generates a corresponding Erlang module, which can encode and decode the specified data types. Alternatively, the compiler takes a specification module specifying all input modules, and generates a module with encode/decode functions.

[devman0]

XML also decouples the data model and serialization with the XML Infoset specification.