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33 lines
943 B
Go
33 lines
943 B
Go
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// run
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Test order of evaluation of index operations.
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package main
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func main() {
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arr := []int{1, 2}
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// The spec says that in an assignment statement the operands
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// of all index expressions and pointer indirections on the
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// left, and the expressions on the right, are evaluated in
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// the usual order. The usual order means function calls and
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// channel operations are done first. Then the assignments are
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// carried out one at a time. The operands of an index
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// expression include both the array and the index. So this
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// evaluates as
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// tmp1 := arr
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// tmp2 := len(arr) - 1
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// tmp3 := len(arr)
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// arr = arr[:tmp3-1]
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// tmp1[tmp2] = 3
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arr, arr[len(arr)-1] = arr[:len(arr)-1], 3
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if len(arr) != 1 || arr[0] != 1 || arr[:2][1] != 3 {
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panic(arr)
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}
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}
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