16f6c0aecf
Inline adoc files when they are included exactly once. Also fix language tags because this inlining gives us better information on what language the code is written in.
83 lines
1.7 KiB
Plaintext
83 lines
1.7 KiB
Plaintext
== Why is this an issue?
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Many existing switch statements are essentially simulations of switch expressions, where each arm either assigns to a common target variable or returns a value. Expressing this as a statement is roundabout, repetitive, and error-prone.
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Java 12 added support for switch expressions, which provide more succinct and less error-prone version of switch.
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=== Noncompliant code example
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[source,java]
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----
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void day_of_week(DoW day) {
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int numLetters;
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switch (day) { // Noncompliant
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case MONDAY:
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case FRIDAY:
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case SUNDAY:
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numLetters = 6;
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break;
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case TUESDAY:
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numLetters = 7;
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break;
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case THURSDAY:
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case SATURDAY:
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numLetters = 8;
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break;
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case WEDNESDAY:
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numLetters = 9;
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break;
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default:
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throw new IllegalStateException("Wat: " + day);
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}
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}
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int return_switch(int x) {
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switch (x) { // Noncompliant
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case 1:
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return 1;
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case 2:
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return 2;
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default:
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throw new IllegalStateException();
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}
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}
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----
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=== Compliant solution
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[source,java]
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----
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int numLetters = switch (day) {
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case MONDAY, FRIDAY, SUNDAY -> 6;
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case TUESDAY -> 7;
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case THURSDAY, SATURDAY -> 8;
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case WEDNESDAY -> 9;
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};
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----
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ifdef::env-github,rspecator-view[]
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'''
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== Implementation Specification
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(visible only on this page)
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=== Message
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Use "switch" expression to set value of "variable".
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Use "switch" expression to return value from method.
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'''
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== Comments And Links
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(visible only on this page)
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=== on 28 Jan 2019, 15:21:02 Tibor Blenessy wrote:
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https://openjdk.java.net/jeps/325
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endif::env-github,rspecator-view[]
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