That's not relevant as to whether it's a turing machine or not, tho...
The possible calculations (and genericity) is what matters. The "button for each step" could be analogous to powering the turing machine, or turning some crank for Babbage's machine, or whatever..
This is absolutely relevant, turing's original definition described a completely autonomous and automatic machine, that's why every turing machine has a halting state that locks it in a loop when computation is finished.
>could be analogous to powering the turing machine, or turning some crank for Babbage's
Those things are done once for those machines, you press power-on or turn a crank for just one time and the machine starts, this is not the case here, here the human is acting as the control logic for the machine, repeatedly pulsing to drive the computation.
Your computer is not a computer without a hardware clock, the repeated pressing of a button is acting as a hardware clock here.
>This is absolutely relevant, turing's original definition described a completely autonomous and automatic machine, that's why every turing machine has a halting state that locks it in a loop when computation is finished.
That's just an accidental part, and is orthogonal to the manual "click next".
The halting state absolutely will be there, locked in a loop and everything, you just manually click to step over each iteration of that loop.
As said, the "click next" is no different that a clock signal in a CPU, or manually cranking the turing machine to play.
It's not at all relevant to the abstraction.
>Your computer is not a computer without a hardware clock, the repeated pressing of a button is acting as a hardware clock here.
Which is exactly why it's an irrelevant detail to the turing machine computation. It's just the clock, not the digital logic.
Whether the hardware clock is internal, or external, or I have a mule rotate around a millstone to drive it, or a big chunk of quartz, is irrelevant, as long the machine is receiving it. This includes me clicking a button to send a pulse.
Let's put it another way, what you're saying is isomorphic to:
"This setup is not a turing machine but this exact setup plus a while loop to repeatedly call xsendkey for Enter is".
>This setup is not a turing machine but this exact setup plus a while loop to repeatedly call xsendkey for Enter is
Yes, that's exactly what I'm saying. And that's why the title is misleading, it's not really Notepad++'s search and replace feature that is turing complete on it's own, because turing complete means "can *Simulate* an arbitary turing machine", the 'can' here is not meant to imply a "if you sat next to it and repatedly pressed enter" kind of remark, it just means you can vary the machine being simulated by varying the input string, but once you enter an input string into the turing-complete system, it should be able to simulate the machine on it's own while you step back and watch. That's what the original machine would have done anyway, so how can you 'simulate' a turing machine if you need something it doesn't ?.
Leave Notepad++'s search and replace feature on a text file containing a transition table for 10^9 years, would it simulate anything on it's own ? On the other hand, leave a JVM running for 10^9 years... you get what I mean.
This is mostly an informal philosophical disagreement on the actual vs. the potential, real academic proofs of turing equivalence side-step the matter of simulation entirely by describing the systems involved in static terms. It's implicitly assumed there is a background animator stepping every system according to its rules.
But I think it's relevant to our intuitive definition of what a computer is, I don't think anyone ships their programs in a form where the user needs to invoke a debugger and repeatedly press 'step over' to get to the next state of the computation. Those kinds of "X is turing complete" headlines circulate on social media and leads people to think 'X' can actually act as an automatic computer, but little do they know the author uses their hand as a hardware clock without really calling attention to it.
No, Babbage's earlier design requires the crank to be turned all the time. Basically human-powered instead of fossil-fuel powered. As long as the human only needs to turn the crank without thinking, the human could always be replaced by a steam engine.
The purpose of Turing completeness is to describe whether a system is capable of performing arbitrary computation. That once a machine is Turing-complete, Church-Turing thesis stipulates it can do any computation that another Turing-complete machine can do, subject to resource and time constraints.
In the early days of computing, where designing and building a general-purpose computer was still a major practical challenge, one could imagine whether the crank is turned by a human wasn't important, because any idea that involves a physical crank can be supplemented by a steam engine, a solved problem. It's very easy to swap out the human for a steam engine - the actual novel problem was to verify that the internal logic of the machine is general-purpose enough.
In that context, one can see what the true spirit of the Church-Turing thesis is. It abstracts away the things that don't need to be part of the picture, so that people can focus on understanding the mathematical notion of computation - what is computable and what isn't, and what kind of designs are capable of computing everything that's computable.
To illustrate, you'd say it's imprecise to say a language is Turing complete - you technically still need a CPU and RAM. But those are just assumed to be available when the true focus is to design a language. Similarly, when designing a mechanical computation machine, whether we have built in the monotonic power source / hardware clock is just not a very important distinction given the context of the design. Everything that holds for Turing-complete machine would still hold, just except the machine needs a power source.
It's true that requiring constant clicks makes the result less interesting (and maybe very much so), but for the spirit of Turing completeness the power source is just a trivial matter.
It's pretty relevant. A simple arithmetic equation becomes Turing complete if a helper system is attached to execute it over and over on the previous output.
The class of things that are Turing complete with one button push is much smaller than the class of things that can run a single step of a Turing machine per button push.
I'm not here to argue about which one is the "real" Turing complete, but they're very distinct groups, and I'd say that getting into the former is significantly more impressive and interesting than the latter.
The possible calculations (and genericity) is what matters. The "button for each step" could be analogous to powering the turing machine, or turning some crank for Babbage's machine, or whatever..