Not a real answer, but there is a similar question [What should I use to execute abi.encodePacked from solidity in starknet?](https://www.newton.so/view/63653eaa0312d46c3357563a)

Newton

Hi,
There is no "out of the box" way of doing this to my knowledge.

So you need to look at the [formal specification](https://docs.soliditylang.org/en/v0.8.11/abi-spec.html#formal-specification-of-the-encoding) and replicate it in Cairo (at least that's what people have done thus far). Yeah.. not an ideal scenario ^^

Hey! The title sort of summarizes the question. I was wondering if there's any project where I can see an example of how something like `keccak256(abi.encodePacked(var1, var2, var3))`  could be achieved in starknet.

If there were a way to concatenate bytes, I think it wouldn't be too complicated, but such a string would never fit in a felt, and using a struct won't result in the same output.

So yes, my question is if there's an equivalent way to achieve this behavior in cairo.

Equivalent to Solidity's keccak256(abi.encodePacked())?

I have a struct with : 

```struct Binary:
felt a:
felt* b:
```

How to return this in a view function?
I see this error:
```
Can't identify return variable
```


how to return struct

 I usually use truffle and solc is installed locally but not globally. Should I installed it? Is it worth adding in the readme?

 How do I check that my Solidity compiler version is >= 0.8.0 ?

Hey guys, quick question. What should I use to execute abi.encodePacked from solidity in starknet?

_This question was originally posted on [StarkNet Discord](https://www.newton.so/view?tags=discord)_

What should I use to execute abi.encodePacked from solidity in starknet?

In SNARKs, you can use Zokrates or snarkjs to generate a proof for a program/computation and verify it, locally or on Ethereum.


Similar to [this unanswered question](https://github.com/starkware-libs/cairo-lang/issues/2), how to do the same in Cairo and STARK for, say, [the 15-puzzle](https://www.cairo-lang.org/docs/hello_cairo/puzzle.html)?


Can `cairo-run` generate a proof, or only a trace?


I can send it to [SHARP](https://www.cairo-lang.org/docs/sharp.html) with cairo-sharp, but I can't generate nor see the proof locally. Any way to generate the proof by running my own prover without SHARP?


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/1138)_

How to generate a proof for a Cairo program and verify it?[StackOverflow]

hey! any idea on how much is starknetJS request limit?

_This question was originally posted on [StarkNet Discord](https://www.newton.so/view?tags=discord)_

Do you have any idea on how much is starknetJS request limit?

In the following function I am presented with the following error, even though my code does not make it to this function. What am I doing wrong?


`func fill_in_row{output_ptr: felt*}(row_idx : felt, row_size : felt, curr_row : felt*) {` 


 `if (row_idx == row_size-2) {`


 `return ();`


 `}`


 `let val : felt = curr_row[row_idx-1] + curr_row[row_idx];`


 `serialize_word(val);`


 `curr_row[row_idx+1] = val;`


 `return fill_in_row(row_idx+1, row_size, curr_row);`


`}`


Error: code:80:5: While expanding the reference 'curr_row' in:


 curr_row[row_idx+1] = val;


 ^******^


code:72:73: Expected a register. Found: [fp + (-4)].


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/1156)_

Cairo Error: Getting Error while setting value of item in array

Just saw this in Cairo v0.10 docs: "support using functions as expressions"
Can anyone explain how does that work exactly? any example would be very helpful
It's mentioned here: https://github.com/starkware-libs/cairo-lang/releases/tag/v0.10.0#:~:text=Support%20using%20functions%20as%20expressions

_This question was originally posted on [StarkNet Discord](https://www.newton.so/view?tags=discord)_

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Equivalent to Solidity's keccak256(abi.encodePacked())?

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