net.sourceforge.pmd.lang.java.ast.ASTSwitchLike Maven / Gradle / Ivy
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/**
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.java.ast;
import java.util.Iterator;
import net.sourceforge.pmd.lang.ast.NodeStream;
import net.sourceforge.pmd.lang.java.symbols.JClassSymbol;
import net.sourceforge.pmd.lang.java.symbols.JTypeDeclSymbol;
/**
* Common supertype for {@linkplain ASTSwitchStatement switch statements}
* and {@linkplain ASTSwitchExpression switch expressions}. Their grammar
* is identical, and is described below. The difference is that switch
* expressions need to be exhaustive.
*
*
*
* SwitchLike ::= {@link ASTSwitchExpression SwitchExpression}
* | {@link ASTSwitchStatement SwitchStatement}
*
* ::= "switch" "(" {@link ASTExpression Expression} ")" SwitchBlock
*
* SwitchBlock ::= SwitchArrowBlock | SwitchNormalBlock
*
* SwitchArrowBlock ::= "{" {@link ASTSwitchArrowBranch SwitchArrowBranch}* "}"
* SwitchNormalBlock ::= "{" {@linkplain ASTSwitchFallthroughBranch SwitchFallthroughBranch}* "}"
*
*
*/
public interface ASTSwitchLike extends JavaNode, Iterable {
/**
* Returns true if this switch has a {@code default} case.
*/
default boolean hasDefaultCase() {
return getBranches().any(it -> it.getLabel().isDefault());
}
/**
* Returns a stream of all branches of this switch.
*/
default NodeStream getBranches() {
return children(ASTSwitchBranch.class);
}
/**
* Gets the expression tested by this switch.
* This is the expression between the parentheses.
*/
default ASTExpression getTestedExpression() {
return (ASTExpression) getChild(0);
}
/**
* Returns true if this switch statement tests an expression
* having an enum type and all the constants of this type
* are covered by a switch case. Returns false if the type of
* the tested expression could not be resolved.
*/
default boolean isExhaustiveEnumSwitch() {
JTypeDeclSymbol symbol = getTestedExpression().getTypeMirror().getSymbol();
if (symbol instanceof JClassSymbol && ((JClassSymbol) symbol).isEnum()) {
long numConstants = ((JClassSymbol) symbol).getEnumConstants().size();
// we assume there's no duplicate labels
int numLabels = getBranches().sumByInt(it -> it.getLabel().getNumChildren());
return numLabels == numConstants;
}
return false;
}
/**
* Returns true if this switch statement tests an expression
* having an enum type.
*/
default boolean isEnumSwitch() {
JTypeDeclSymbol type = getTestedExpression().getTypeMirror().getSymbol();
return type instanceof JClassSymbol && ((JClassSymbol) type).isEnum();
}
@Override
default Iterator iterator() {
return children(ASTSwitchBranch.class).iterator();
}
/**
* Returns true if this a switch which uses fallthrough branches
* (old school {@code case label: break;}) and not arrow branches.
* If the switch has no branches, returns false.
*/
default boolean isFallthroughSwitch() {
return getBranches().filterIs(ASTSwitchFallthroughBranch.class).nonEmpty();
}
}