Convert Bytes type

[meevee98]

• Implemented conversion of literal bytes
• Implemented get to bytes indexes. Python's bytes object does not support item assignment
• Implemented bytes len() method.

[ixje]

I quickly scrolled through the code and I believe we map Python bytes to the VM Buffer stackitem right?

As far as I know the only difference between bytes and bytearray is the former is immutable and the latter is mutable. I believe the equivalent for the VM would be Buffer and ByteString. I don't know if you are aware of this distinction in the NEO VM? Even though they currently still work slightly different, but I'm working on trying to get that resolved in neo-project/neo-vm#332

What do you think? Should bytes map to ByteString and bytearray to Buffer or is there a good reason not to do this?

[meevee98]

I was thinking of resolving this difference between bytes and bytearray with the type checking that is made by the compiler. I think the relationship between bytes and bytearray is the same between tuple and list. Both tuple and list are mapped to VM Array, but we are not allowing to change variables typed as tuple aside of reassigning them

The main point to map the bytes to Buffer it's because of the type of values. As far I tested, when you use PICKITEM opcode with VM Buffer the return is an Integer and using the same opcode with a VM ByteString the return is a Buffer. Between these two, the one having the same behavior of Python bytes get is the first.

[ixje]

I was thinking about what restrictions the actual VM enforces, but enforcing it on the compiler side is actually very powerful. I like it!

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On 11 Jun 2020, at 18:02, Mirella de Medeiros ***@***.***> wrote:  I was thinking of resolving this difference between bytes and bytearray with the type checking that is made by the compiler. I think the relationship between bytes and bytearray is the same between tuple and list. Both tuple and list are mapped to VM Array, but we are not allowing to change variables typed as tuple The main point to map the bytes to Buffer it's because of the type of values. As far I tested, when you use PICKITEM opcode with VM Buffer the return is an Integer and using the same opcode with a VM ByteString the return is a Buffer — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.