You just went to the Google home page.

Simple, isn't it?

What just actually happened?

Well, when you know a bit of about how browsers work, it's not quite that simple. You've just put into play HTTP, HTML, CSS, ECMAscript, and more. Those are actually such incredibly complex technologies that they'll make any engineer dizzy if they think about them too much, and such that no single company can deal with that entire complexity.

Let's simplify.

You just connected your computer to www.google.com.

Simple, isn't it?

What just actually happened?

Well, when you know a bit about how networks work, it's not quite that simple. You've just put into play DNS, TCP, UDP, IP, Wifi, Ethernet, DOCSIS, OC, SONET, and more. Those are actually such incredibly complex technologies that they'll make any engineer dizzy if they think about them too much, and such that no single company can deal with that entire complexity.

Let's simplify.

You just typed www.google.com in the location bar of your browser.

Simple, isn't it?

What just actually happened?

Well, when you know a bit about how operating systems work, it's not quite that simple. You've just put into play a kernel, a USB host stack, an input dispatcher, an event handler, a font hinter, a sub-pixel rasterizer, a windowing system, a graphics driver, and more, all of those written in high-level languages that get processed by compilers, linkers, optimizers, interpreters, and more. Those are actually such incredibly complex technologies that they'll make any engineer dizzy if they think about them too much, and such that no single company can deal with that entire complexity.

Let's simplify.

You just pressed a key on your keyboard.

Simple, isn't it?

What just actually happened?

Well, when you know about bit about how input peripherals work, it's not quite that simple. You've just put into play a power regulator, a debouncer, an input multiplexer, a USB device stack, a USB hub stack, all of that implemented in a single chip. That chip is built around thinly sliced wafers of highly purified single-crystal silicon ingot, doped with minute quantities of other atoms that are blasted into the crystal structure, interconnected with multiple layers of aluminum or copper, that are deposited according to patterns of high-energy ultraviolet light that are focused to a precision of a fraction of a micron, connected to the outside world via thin gold wires, all inside a packaging made of a dimensionally and thermally stable resin. The doping patterns and the interconnects implement transistors, which are grouped together to create logic gates. In some parts of the chip, logic gates are combined to create arithmetic and bitwise functions, which are combined to create an ALU. In another part of the chip, logic gates are combined into bistable loops, which are lined up into rows, which are combined with selectors to create a register bank. In another part of the chip, logic gates are combined into bus controllers and instruction decoders and microcode to create an execution scheduler. In another part of the chip, they're combined into address and data multiplexers and timing circuitry to create a memory controller. There's even more. Those are actually such incredibly complex technologies that they'll make any engineer dizzy if they think about them too much, and such that no single company can deal with that entire complexity.

Can we simplify further?

In fact, very scarily, no, we can't. We can barely comprehend the complexity of a single chip in a computer keyboard, and yet there's no simpler level. The next step takes us to the software that is used to design the chip's logic, and that software itself has a level of complexity that requires to go back to the top of the loop.

Today's computers are so complex that they can only be designed and manufactured with slightly less complex computers. In turn the computers used for the design and manufacture are so complex that they themselves can only be designed and manufactured with slightly less complex computers. You'd have to go through many such loops to get back to a level that could possibly be re-built from scratch.

Once you start to understand how our modern devices work and how they're created, it's impossible to not be dizzy about the depth of everything that's involved, and to not be in awe about the fact that they work at all, when Murphy's law says that they simply shouldn't possibly work.

For non-technologists, this is all a black box. That is a great success of technology: all those layers of complexity are entirely hidden and people can use them without even knowing that they exist at all. That is the reason why many people can find computers so frustrating to use: there are so many things that can possibly go wrong that some of them inevitably will, but the complexity goes so deep that it's impossible for most users to be able to do anything about any error.

That is also why it's so hard for technologists and non-technologists to communicate together: technologists know too much about too many layers and non-technologists know too little about too few layers to be able to establish effective direct communication. The gap is so large that it's not even possible any more to have a single person be an intermediate between those two groups, and that's why e.g. we end up with those convoluted technical support call centers and their multiple tiers. Without such deep support structures, you end up with the frustrating situation that we see when end users have access to a bug database that is directly used by engineers: neither the end users nor the engineers get the information that they need to accomplish their goals.

quanto tempo avresti da dedicargli?
"giusto quando sono seduto al cesso... cerco qualcosa che non porti via più di un paio di ore di lettura, cosa mi consigli?"

Fondamentalmente credo che Riko e qualcun altro sul forum non abbiano molta simpatia per i dilettanti della programmazione.

Citazione da: GlennHK - Ottobre 12, 2013, 14:29

Il mio modesto parere sull'argomento è: che ne pensate di una persona che "solo per passatempo" decide di fare il muratore, l'imbianchino, il chirurgo ecc...? Può iniziare da zero senza saperne niente (se non quello che detta il senso comune, che in alcuni casi non basta)? Applicatelo alla programmazione. E' facile dire "si, non ti piace, non è molto leggibile ma funziona e chi se ne frega", ma quello che voglio dire è che anche "i programmatori per hobby" dovrebbero sforzarsi di ragionare prima di buttare giù codice molto spesso orribile. E la cosa che più non concepisco sono quelli che provano a copiare cose da esempi, non gli funziona e corrono a chiedere aiuto. Le cose prima si studiano, si comprendono appieno, poi si provano. Se non si capisce, allora si chiede. Esiste la documentazione, google, vari libri, eccetera.

Vero, per imparare bisogna studiare e nei lavori manuali, in cui lo studio sta dentro la pratica, non si può imparare se non ci si esercita. In programmazione l'esercizio serve. Serve come fissativo dei concetti studiati. Quasi sicuramente i primi approcci di codice saranno rudimentali, ma, con l'esercizio, l'esperienza e continuando a leggere e meditare su tutto quanto vissuto, la crescita diventerà, piano piano, un percorso inconsciamente inevitabile. Ciò vale sia per gli hobbisti che per i professionisti. Se, pensando ad un progetto, bisognasse aspettare di raggiungere la perfezione teorica, non si comincerebbe mai, perchè , nonostante la conoscenza fotografica di tutta la teoria studiata, il primo impatto con la pratica farà sempre pagare pegno. Nel frattempo anche gli strumenti studiati avranno fatto passi avanti ed il povero apprendista-programmatore, si vedrà ricacciato sui libri. Sempre, nell'ambito del puro ragionamento, si troverebbe immerso in un loop infinito.
 

Tu sai benissimo che i linguaggi, cosiddetti, di altissimo livello, sono realizzati attraverso la costruzione di funzioni macro che contengono al loro interno grandi quantità di codici elementari. Sono dette istruzioni che l'interprete ricava e che esegue nel puro linguaggio macchina, da dare in pasto al processore del pc (dico processore e non processori per non complicarmi la vita e per non dilungarmi oltre lo strettamente necessario). Se il linguaggio è invece uno di quelli che richiedono la compilazione, la conversione in linguaggio macchina la fa il compilatore.

Quello che conta è la capacità di costruire con razionale consecutività insiemi di istruzioni evolute che permettano all'utente-programmatore (non al programmatore-utente) di arrivare al risultato cercato. Per fare ciò, a parte l'applicazione della dovuta logicità, il maggiore sforzo che il nostro utente-programmatore deve compiere è, secondo me,  capire il meccanismo delle istruzioni nidificate o annidate, come le vogliamo chiamare.