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Comment by joatmon-snoo | Hacker News Reader

I've actually found that there are a number of situations where I really want:

  while True:
    ...
    if condition:
      break
    ...

and kinda wish there was a nicer syntax for this.

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And this is where I really miss Sather:

  loop
    while!(condition);
    ...
  end;

for while, versus

  loop
    ...
    while!(condition);
  end;

for do-while, and

  loop
    ...
    while!(condition);
    ...
  end;

in place of:

  while True:
    ...
    if not condition:
      break
    ...

Alas, it never really took off.

A Ruby-like “until” or Pascal “repeat...until” (C’s do...while is equivalent but less clear choice of keywords, IMO.) The Pascal form wouldn't really fit Python's indentation-without-closing-marker block syntax preference, but the Ruby version would.

If it existed, I’d be tempted to suggest a linter rule that prohibits break inside an until (it should only be used when the main exit condition is the only exit condition.)

Too late to correct, but I can tell I haven't been using Ruby much for a while; Ruby until is just negated while, like C it uses while (or until!) at the end for Pascal-style repeat...until logic.

Rust has `loop {}` which I thought was weird at first, but also ended up use more than I would have expected.

One especially nice part of rust's `loop` is since it's guaranteed to run at least once and to terminate, you can break with a value!

    let foo = loop {
        // ...
        if condition {
            break value;
        }
        // ...
    }

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