Break and continue support

samples/language/BreakAndContinue.qs

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+// # Sample
+// Break and Continue
+//
+// # Description
+// The `break` statement immediately exits the innermost enclosing loop.
+// The `continue` statement skips the rest of the current iteration and
+// proceeds to the next one. Both can be used in the bodies of `for`,
+// `while`, and `repeat`-`until` loops. They cannot be used in loop
+// conditions or in `repeat`-`until` fixup blocks.
+
+function Main() : (Int, Int, Int) {
+    // Use `break` to stop a loop early. Here we find the first integer whose
+    // square exceeds 50 and then stop searching.
+    mutable firstOverFifty = 0;
+    for n in 1..100 {
+        if n * n > 50 {
+            firstOverFifty = n;
+            break;
+        }
+    }
+
+    // Use `continue` to skip selected iterations. Here we sum the numbers from
+    // 1 to 20, skipping every multiple of 3.
+    mutable sumWithoutMultiplesOfThree = 0;
+    for n in 1..20 {
+        if n % 3 == 0 {
+            continue;
+        }
+        sumWithoutMultiplesOfThree += n;
+    }
+
+    // `break` and `continue` also work in `while` loops. Here we count how many
+    // times 1 can be doubled before the result exceeds 1000.
+    mutable doublings = 0;
+    mutable value = 1;
+    while true {
+        value *= 2;
+        if value <= 1000 {
+            doublings += 1;
+            continue;
+        }
+        break;
+    }
+
+    return (firstOverFifty, sumWithoutMultiplesOfThree, doublings);
+}