[mikewarot]

The closest thing I've seen to truly multi-paradigm was a programming language now lost to time called Metamine, which I kept a clone of[1]. Here's some previous discussion[2]

In Metamine

   a := b   is a normal assignment
   c = d+1   means that c will ALWAYS be equal to d+1 
   z = 10-time    results in a countdown timer, z

That magical equals is declarative programming... something that I've only seen mixed with imperative functioning that one time.

[1] https://github.com/mikewarot/metamine

[2] https://news.ycombinator.com/item?id=27555940

[mpweiher]

IIRC, this was called "permanent assignment" in CPL, a name I very much like.

It's also pretty much the same as a dataflow constraint (see: Amulet, Garnet, Spreadsheets, ...)

In Objective-S, I use the syntax |= for the unidirectional variant of a dataflow constraint, =|= for bidirectional (ObjS uses := or ← for assignment, = for equality). So the above would be:

    a := b.
    a ← b.
    c |= d+1.
    z |= 10-time.  (if 'time' were the current time in ObjS)

https://objective.st

[lanna]

Easy to achieve the same in any language that supports the uniform access principle, and it does not even look magical

[ivanjermakov]

Looks like reactive programming to me. Very similar to spreadsheet formulas.