Dmitry Petrov
e2fa613b70
If the range expression is not a local variable (which can be updated in the loop body affecting loop behavior, see KT-21354), we can cache the array length, thus turning a for-in-array loop into a simple optimizable counter loop. #KT-21321 In Progress
23 lines
868 B
Kotlin
Vendored
23 lines
868 B
Kotlin
Vendored
// WITH_RUNTIME
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// IGNORE_BACKEND: JS
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// In Kotlin 1.0, in a for-in-array loop, range expression is cached in
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// a local variable unless it is already a local variable.
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// This caused the following quirky behavior:
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// if an array variable is updated in the loop body, it affects the loop
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// execution (see https://youtrack.jetbrains.com/issue/KT-21354).
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// Most likely it is a bug, however, fixing it right now is a breaking
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// change requiring a proper deprecation loop.
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// When the design decision is made, it might be required to update this
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// test (e.g., by adding a proper LANGUAGE_VERSION directive).
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// Note that JS back-end handles this case "correctly".
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fun box(): String {
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var xs = intArrayOf(1, 2, 3)
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var sum = 0
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for (x in xs) {
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sum = sum * 10 + x
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xs = intArrayOf(4, 5)
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}
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return if (sum == 15) "OK" else "Fail: $sum"
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} |