JCTools VS bips

Install some tool that would help you see the performance of your system, like a graph of the CPU usage, the top processes being used, disk activity/read/write, etc. Every time you run your program, glance at those numbers, eventually you'll develop an intuition. Basically write code and profile. A good exercise would be practicing with data structures, this site has an exhaustive list of them, find some stuff that's interesting then google the implementation, then build it yourself, test it, debug, profile, optimize, and understand the performance constraints. Eventually you'll develop better understanding and can compare between other people's works, optimizing them. If you want to go beyond, read some papers on lock-free algorithms https://github.com/JCTools/JCTools/tree/master/resources then read Brendan Gregg's blog and books. Read about how profiling tools work https://github.com/andikleen/pmu-tools/wiki/toplev-manual

If I fork this implementation's repo and then publish a release (of the forked version) with my own commits via jitpack.io (committing with Android Studio IDE).

BIPs (Bitcoin Improvement Proposals)

Some years ago, I saw a wallet called [Spark](https://sparkwallet.io/) that let you generate a QR-code to view in your Apple Wallet and Apple Watch Wallet. It was for receiving over lightning, not sending.

I guess with unified [BIP21](https://github.com/bitcoin/bips/blob/master/bip-0021.mediawi...) QR-codes, anyone can already add a RECEIVING wallet code to Apple Wallet today.

I don't think Apple want's to be the middle man in receiving Bitcoin payments though because “tainted” coins exist in the C-suite mind, and they would rather not receive and handle those.

But Jack Mallers recently told me he wants to integrate Apple Pay into [Strike](https://strike.me), so who knows, something similar will exist soon.

Anything you put elsewhere is not more secure, unless you are more secure than Apple's servers, which seems highly unlikely. If you don't have it, it can't get compromised.

The user has an iCloud account, you can write to iCloud storage without making them "sign in" to your app. It's their data, they can find it in the folder for your app in their iCloud drive on a Mac.

And see https://developer.apple.com/game-center/ for a way to let two users coordinate "play", multiplayer, turn based, achievements, etc., which cover most of the interaction you'd need.

For sharing personality test, a person can do their own and their partner's, but for a better take on the partner you and your partner can each take your own test then generate a sharable fun code that captures the "bits" of the answers without repeating the test. As partners, you could tell each other the sharable code as a NFC bump or QR code to scan, or generate one of the word based codes like bitcoin wallet passwords.

See BIP39: https://github.com/bitcoin/bips/blob/master/bip-0039.

(This passphrase would be short if the test results distill down to a smaller set of outcomes, like 64 questions give 8 results. It would be long if you need all 64 questions' answers to match with.)

Modern bitcoin addresses use a base-32 character set that leaves out some of the most ambiguous pairs and also permutes the address ordering so that the most visually similar remaining characters produce single bit errors which are better handled by the addresses error detecting (and potentially correcting) code.

https://github.com/bitcoin/bips/blob/master/bip-0173.mediawi...

Context: Bitcoin miners have just adopted a 50% pay cut for themselves. This pay cut was baked into Bitcoin protocol at the launch of the network (mostly, see "BIP 42" [1]). The OP link gives information about the block in which this pay cut was made.

I get that HN comments tend to dismiss Bitcoin. But the fact that for the fourth time this pay cut has happened without a hitch speaks volumes to what makes Bitcoin interesting: It's a rare combination of economic incentives and technology that keeps chugging. Nobody can stop it. And it's extremely resistant to change. It requires no governmental approval. All attempts at subversion or interference have failed. There aren't many things that come close to that kind of record.

[1] https://github.com/bitcoin/bips/blob/master/bip-0042.mediawi...

Bitcoin transactions involve locking funds in scripts, which can only be spent if those locking conditions are met. The part of the script that expresses these locking conditions are called ScriptPubKeys. On the other hand, the part that provides unlocking scripts to satisfy the locking conditions is referred to as ScriptSig for legacy transactions, and ScriptWitness for SegWit Transactions. These scripts are evaluated by a stack-based language called Script. This article will mainly focus on ScriptPubKeys.