Thread by @alcueca

Today, I'm speedrunning Cairo.

First stop, "Moving from Solidity to Cairo" from the cairo-lang website, just to get an idea of what is that we are going to do.

cairo-lang.org/moving-from-so…

The thing that makes Cairo less scary after reading that article is that you don't need to know that much of what goes under the hood to get started. It's just another programming language so far.

Next stop, read the first few chapters of the cairo book to get a handle of the syntax. Variables and control flow is all you need to start.

book.cairo-lang.org

After that, I've just quickly installed the dev tools, and I'm going to code an ERC20 from what I remember from the first article, using the cairo book. Let's go.

The book, the tutorial and the compiler all disagree on how to create a mapping/dictionary.

Today, we dine in hell.

Removed all functionality and started again.
Instantiating a contract with constructor arguments has been achieved internally.
But all the constructor arguments need to be the same type, weird.
Off to discord we go.

Never mind, I learnt about casting.

Oh joy

Google is dead to me

I spent probably two hours trying to print an address to console before giving up and finding a different way to test that `balanceOf` works.

Having something as basic as an address to be an import gives me strong BigNumber vibes. Yikes.

Thanks to the good people at the discord I learnt that you can create arbitrary addresses as:

`let holder: ContractAddress = 1234.try_into().unwrap();`

The mint and transfer functions were a breeze, now stuck with nested mappings for allowances.

You don't fool me, I know that's not the actual error:

It meant "Type not found" ... as a parameter in the implementation 50 lines below.

Dick.

Almost there, I just need to test `transferFrom` and add events.

Alas, I've got to go get the kids from school. Time to stop.

Today, I got from zero to a working erc20 in cairo.

Tomorrow, I'll dig into the @ChakraChain codebase in @code4rena :D

Bring on the pain.