[Octave-bug-tracker] [bug #55995] "continue" is dynamically, not lexically scoped - callable from functions without for loops

[Andrew Janke]

Follow-up Comment #1, bug #55995 (project octave):

Oops. Messed up the formatting and it lost most of my post. Re-post:

In Octave, you can call "continue" from within a function that does not itself
contain a for loop, and it will either cause a continuation in a for loop in a
calling function, or do nothing.

Example:

looper.m:


function looper
  for i = 1:5
    fprintf ("before\n");
    other_fcn ();
    fprintf ("after\n");
  end
end


other_fcn.m:


function other_fcn
  continue
end


Output:


>> looper
before
before
before
before
before
>> continue
>> continue
>> continue
>> other_fcn
>> other_fcn
>>


Note that you can just call continue even if there's no for loop in the
enclosing dynamic scope, and it does nothing.

Is this expected behavior? I saw it discussed over in
https://savannah.gnu.org/bugs/?48665 related to a crash, but not mentioning
that the behavior itself is odd.

Break doesn't behave the same way: it raises an error if you try to call it
outside the lexical scope of a for loop.

call_break.m:

function call_break
  break
endfunction



>> break
parse error:

  break must appear in a loop in the same file as loop command

>>> break
        ^

>> call_break
parse error near line 2 of file /Users/janke/tmp/octave-continue/call_break.m

  break must appear in a loop in the same file as loop command

>>>   break
          ^

>>




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