DreamBerd

DreamBerd copied to clipboard

It feels like the section on maybe could really use an example of what trying to do if (maybe) ... does.

I see two possible possibilities:

• The if statement gives up and produces and error
• The if statement picks randomly between true and false

it would do it either probably or half probably = 50% chance to do it half = counter = counter + 10 would just add 5

I'd recommend that maybe infers its chance depending on how it has been generated:

b = maybe!  // 50% true
b = maybe & true!  // 66.666..% true
b = maybe & true & true!  // 75% true
...

As far as I know, there's some sort of "probabilistic boolean algebra", but I can't recall how it is named. IIRC, && boils down to a multiplication of probabilities, and a || b boils down to min(a+b,1), but I could be wrong.

maybe should roll a coin(pick 0 or 1) and do the operation at a 50% chance. however, we will be also be able to use percentages because maybe && true is too much.

b = 50%! // same as maybe
c = 90% // likely
d = 10% // unlikely

and i think that "maybe" was a const const const variable made by some user

The compiler will implement quantum superposition in the manner described: https://github.com/TodePond/DreamBerd/discussions/271

On machines where quantum superpositions can't be used, the compiler should instead do some parts of both branches. For example like this:

if(maybe) {
   print("Hello World")
   print("1")
   print("a")
   print("b")
} else {
   print("else")
   print("x")
   print("2")
   print("3")
}

// Result:
Hello World
1
2
3

Which lines get selected could be up to runtime randomness, as long as 50% of lines of each branch get executed.

Another option would be to introduce definitely (or short def) as a response to maybe.

if(maybe) {
   print("true")
} else {
   print("false")
} def {
   print("Hi")
}

// Result:
Hi

The obvious behaviour for

if (maybe)
     callMeMaybe()!

To never call. This is the expected behaviour as demonstrated by user Carly R Jepson.

As far as I know, there's some sort of "probabilistic boolean algebra", but I can't recall how it is named. IIRC, && boils down to a multiplication of probabilities, and a || b boils down to min(a+b,1), but I could be wrong.

I'd guess a || b would be 1 - (1-a)*(1-b) i.e. to find the probability that either are true, invert the probability that both are false.

It seems that DreamBerd is using ternary logic, and I think the third value usually simply represents that the value is unknown, not specifying any particular probability. I guess one way to approach this, if only variable assignments were involved, would be to apply any assignments that were consistent between both branches, and set any variables that were assigned differently between branches to be undefined.

e.g. given

if (condition) {
  x = 1!
  y = 2!
} else {
  x = 1!
  y = 3!
}

x would be set to 1 and y would be set to undefined. This would be complicated to implement, though, and would only work for variable assignment, not output, so I don't think it's really practical.

I think Snapstromegon's second suggestion, of adding a third clause to the if statement is probably more practical. I'd possibly rename it, though. Perhaps: if () {} indoubt {} else {}

Again, there's a formal specification for that "fuzzy boolean", I just can't remember the name, and I fail to cite from memory.

Fuzzy memory?

On Thu, 16 Nov 2023, 06:21 Steffen Ohrendorf, @.***> wrote:

Again, there's a formal specification for that "fuzzy boolean", I just can't remember the name, and I fail to cite from memory.

— Reply to this email directly, view it on GitHub https://github.com/TodePond/DreamBerd/issues/235#issuecomment-1813354219, or unsubscribe https://github.com/notifications/unsubscribe-auth/AA46MLPBHRUM6X6KQL2753LYEU55HAVCNFSM6AAAAAAZ6GGUYOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMJTGM2TIMRRHE . You are receiving this because you commented.Message ID: @.***>

It's actually called Fuzzy Logic :/

No, I meant, you "fail(ed) to cite from [your] (fuzzy) memory".

On Thu, 16 Nov 2023, 13:24 Steffen Ohrendorf, @.***> wrote:

It's actually called Fuzzy Logic https://en.wikipedia.org/wiki/Fuzzy_logic :/

— Reply to this email directly, view it on GitHub https://github.com/TodePond/DreamBerd/issues/235#issuecomment-1813809738, or unsubscribe https://github.com/notifications/unsubscribe-auth/AA46MLJALCUFS44RUZQLYJ3YEWPRVAVCNFSM6AAAAAAZ6GGUYOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMJTHAYDSNZTHA . You are receiving this because you commented.Message ID: @.***>

OK. I was just going by what was written in your comment. You mentioned "multiplication of probabilities". Assuming we're working with probabilities, a && b would be a * b for independent variables. Under the same conditions, a || b would be 1 - (1-a)*(1-b), I think.