@Pickett "If x is initially true then it's important that it doesn't evaluate the false statement, and vice versa." - but for that you don't need Hold/ReleaseHold, do you? Isn't If enough?

@Pickett " However every time I toggle between true and false it reevaluates the expressions, I don't want that either." how the If check should be done otherwise? Or have I misunderstood "expression"

@Pickett I'm not sure what is the goal but maybe something along those lines:

ClearAll[f]
 f[x : (True | False)] := f[x] = If[x, Print[1]; true, Print[2]; false]
Dynamic@f[x]
Checkbox@Dynamic@x

Hi guys! There is a way in Mathematica to make plots like this one?

The red points are poles of a complex function and the sawtoothed lines are branch-cut. This complex functions is a priori unknown

@Kuba Thanks, I'm sorry for being unclear, I wasn't thinking clearly overall last night. I see now that If is HoldRest and so yes, the holds should be unnecessary. I have a follow up question related to what I said in the end of my last question, "and I don't like it too much either since true and false can be large, complex expressions." I'd like to do something like:

ClearAll[f, b]

SetAttributes[f, HoldRest]
f[x : (True | False), true_, false_] :=
 With[{tr = Hash[true], fa = Hash[false]},
  f[x, tr, fa] = If[x,
    Print["true"]; true,
    Print["false"]; false
    ]
  ]

With[{true = RandomInteger[100, 10], false = RandomInteger[100, 10]},
 Dynamic@f[b, true, false]]

Checkbox@Dynamic@b

@Pickett what about my code, where contents are not arguments? only x

It works if I remove Hash, so the hash is the problem for some reason.

@Pickett probably because you are casching for hashed arguments while you have still original epxressions in `Dynamic.

oh yes, I see that now facepalm

@Pickett What if you have twice the same gui, should it be cached globally or per gui?

@Kuba I would expect it to be cached globally, but it won't happen

@Pickett I'd probably use different or local f for each gui.

But if you aim in reusable and stable gui element like HoldAndCachePaneSelector then I think it is a good question for main.

@Kuba I will see if I can make local functions work for my use case, if not I will post it to main. Thanks.

@p

@Pickett the problem with localization is that if DynamicModule variable is big and you have many of them, it will slow the FE down.

That is why I don't know how to solve general problem but creating private fs functions for specific gui should not be a problem.

@Kuba This has the properties I was looking for:

ClearAll[f, b]
SetAttributes[f, HoldRest]
f[x : (True | False), true_, false_] :=
 With[{tHash = Hash[true], fHash = Hash[false]},
  f[x, _?(Hash[#] == tHash &), _?(Hash[#] == fHash &)] = If[x,
    Print["true"]; true,
    Print["false"]; false
    ]
  ]
With[{true = RandomInteger[100, 10], false = RandomInteger[100, 10]},
 Dynamic@f[b, true, false]]
Checkbox@Dynamic@b

nvm, I'm so slow thinking today omg.

Hi :)

Do you know if it is possible to only sort parts of lists? Like list[[All,1;;6]] stays the same and list[[All,7;;]] gets sorted?

@pH13-YetanotherPhilipp ` list[[All,7;;]] = Sort @ list[[All,7;;]]`

@Kuba Thank you!

I'd expect this to not need to call the Kernel while resizing the Pane:

DynamicModule[{x = {123, 123}},
 Panel@Pane[Dynamic[x], ImageSize -> Dynamic[x],
   Scrollbars -> {False, True}]
 ]

But link snooper says it does. Should that be the case?

@Kuba The problem you helped me with earlier was a misguided attempt at answering this question. Please check it out when you have the time.