Can't pattern match on bytearray

[KristianBalaj]

What Git revision are you using?

aiken v1.0.24-alpha+982eff4

What operating system are you using, and which version?

• Linux / Ubuntu
• Linux / Other
• macOS
• Windows

Describe what the problem is?

The following code fails to compile:

use aiken/transaction/value.{AssetName}

validator(param: AssetName) {
    fn spend(_, __, ___) -> Bool {
        when param is {
            "Foo" -> False
            "Bar" -> False
            _ -> True
        }
    }
}

With the following error message:

        Error aiken::parser

  × While parsing files...
  ╰─▶ I found an unexpected token '"Foo"'.
      
   ╭─[...../my_validator.ak:5:1]
 5 │         when param is {
 6 │             "Foo" -> False
   ·             ─────
 7 │             "Bar" -> False
   ╰────
  help: Try removing it!

      Summary 1 error, 0 warnings
Build failed

What should be the expected behavior?

I should be able to pattern match on ByteArray.

[KtorZ]

@KristianBalaj I should be able to pattern match on ByteArray.

Why? What's the use-case here? Why can a pattern-match do than an if/else can't do?

[KristianBalaj]

Sure, there's not much difference, just a matter of preference.
I thought it's an unexpected behavior so reporting it.

EDIT: Feel free to close it in case you think otherwise

[KtorZ]

It could easily become a syntactic sugar. Not necessarily against the idea, but I like it when things are backed by a use-case ☺️. So I genuinely wondering if there's a legitimate use-case here? The only thing I can imagine from the top my head is wanting to route some logic based on a provided string, which sounds:

• (a) more expensive that it could be with an Int or just an enum alternative, and;
• (b) possibly deadly since the input domain is basically infinite (forcing a hole as a last clause, preventing the compiler to catch future changes).

[KristianBalaj]

The snippet I've given is to just display minimal example. But to give you a specific use case.
I'm writing a logic that controls an addition of a field to a datum (spending UTXO with datumV1 and producing UTXO with datumV2). This new field depends on an AssetName field and I want to account only for specific ones (this is where I wanted to use the pattern match).

[MicroProofs]

Let's add this in the next update too since it's easy.