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  1. [4]
    unknown user
    Link
    N. Wirth's Oberon-07 had a different use case for the ELSIF keywords in loops. They delimited different exit conditions and the corresponding code blocks. Example (the Euclidean algorithm): WHILE...

    N. Wirth's Oberon-07 had a different use case for the ELSIF keywords in loops. They delimited different exit conditions and the corresponding code blocks. Example (the Euclidean algorithm): 

    WHILE m > n DO
	m := m – n
ELSIF n > m DO
	n := n – m 
END

    This is equivalent to the C code: 

    while (true) {
	if (m > n) {
		m = m - n;
	} else if (n > m) {
		n = n - m;
	} else {
		break;
	}
}

    (There is another way of writing it in C, but this one is closer to the Oberon-07 version.)

    5 votes
    1. [3]
      Apos
      Link Parent
      I had that as a proposed loop in my language. I had named it the coil loop. I have since dropped it.

      I had that as a proposed loop in my language. I had named it the coil loop. I have since dropped it.

      2 votes
      1. [2]
        unknown user
        Link Parent
        Wirth himself calls it (PDF) “Dijkstra's form”, although Google doesn't seem to know that name. So you could do something like: EWD m > n DO m := m – n ELSIF n > m DO n := n – m END

        Wirth himself calls it (PDF) “Dijkstra's form”, although Google doesn't seem to know that name. So you could do something like: 

        EWD m > n DO
	m := m – n
ELSIF n > m DO
	n := n – m 
END
        2 votes