quick question anyone knows how to get the signature bytes4 (msg.sig) of a function from an external call from another contract ?

when i use bytes4 addEthC = msg.sig; i get the signature from the function that sets the variable, want the function of origin

I'm pretty sure that you're limited to what you can find here:

https://docs.soliditylang.org/en/v0.8.13/units-and-global-variables.html#block-and-transaction-properties

So you're out of luck

Found another solution instead of using function signature. Think it can be done with solidity inline assembly

What even is your goal?

the token I'm making right now regulates its own supply within the lp pair based on price setting from external validators, it is also also determined by buys and sells. For it to work users cant be allowed to add liquidity to that specific pair, it regulates its own liquidity, that is what i needed a solution for.

I don't understand it entirely. Are you trying to make a token that cannot be used in a decentralized exchange?

How come adding liquidity messes the price...

it doesn't, if more weth is added on buys, more tokens are added to lp to maintain price the validator sets, lp supply stays the same

this is an issue

Oh you want to maintain lp token supply a constant?

yes, there will only be added liquidity once

Thats a tough one. Btw applying limit on router level can be circumvented easily

yeah, limit wont do it, tried messing with function signature, no luck on that

unless you use a dex you build you have no way to distinguish between an add of liquidity or a sell or a withdraw of lp and a buy

btw reading through solidity's changelog just found out something cool
https://soliditytips.com/articles/concatenate-strings-solidity/

way more readable then the previous solution we got used to

it is on a dex i build, just didn't account for it when i made it

yeah by dex you build I meant something foe which you can adjust code to fix that, if that's already deployed and is not upgradable that won't change anything

absolutly

oh damn

thats sweet !

Yeah! Ahahah

yep yep, always read them when you see a new version

do we have substring (in js) equivalent in solidity?

Not natively, either you code it or Idk, maybe you can find a 3rd party lib that has it implemented

https://github.com/Arachnid/solidity-stringutils

why they should be the same?

that is a modifier

Yes i know ! And all modifications are made each it's call, isn't it?

It's using a syntax that you could've made yourself in every solidity version I'm aware of

Only natively supported in calldata

Mmhh no, string.concat hasn't always been around

Read again: you could've defined it to be exactly like that function

Yes, of course I could have written a function to behave in the same way

You could've made a contract or a library and you could've implemented a function "concat()" in it that behaves identically

Of course

Well that's not always the case. So no "of course"

For example the call data slicing was not available until recently

You couldn't have written a function that behaved identically (i.e. no gas costs)

Well, it's not like we didn't have a way to concat strings before that and I didn't think there was even a nees to explicit it

And you also couldn't have yielded that syntax

Mmh