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package com.github.javaparser.ast.validator.chunks;
import com.github.javaparser.ast.Node;
import com.github.javaparser.ast.body.Parameter;
import com.github.javaparser.ast.body.VariableDeclarator;
import com.github.javaparser.ast.expr.ArrayCreationExpr;
import com.github.javaparser.ast.expr.LambdaExpr;
import com.github.javaparser.ast.expr.NullLiteralExpr;
import com.github.javaparser.ast.expr.VariableDeclarationExpr;
import com.github.javaparser.ast.stmt.ExpressionStmt;
import com.github.javaparser.ast.stmt.ForStmt;
import com.github.javaparser.ast.stmt.ForeachStmt;
import com.github.javaparser.ast.type.VarType;
import com.github.javaparser.ast.validator.ProblemReporter;
import com.github.javaparser.ast.validator.TypedValidator;
import java.util.Optional;
public class VarValidator implements TypedValidator<VarType> {
private boolean varAllowedInLambdaParameters;
public VarValidator(boolean varAllowedInLambdaParameters) {
this.varAllowedInLambdaParameters = varAllowedInLambdaParameters;
}
@Override
public void accept(VarType node, ProblemReporter reporter) {
// All allowed locations are within a VariableDeclaration inside a VariableDeclarationExpr inside something else.
Optional<VariableDeclarator> variableDeclarator = node.findParent(VariableDeclarator.class);
if (!variableDeclarator.isPresent()) {
// Java 11's var in lambda's
if (varAllowedInLambdaParameters) {
boolean valid = node
.findParent(Parameter.class)
.flatMap(Node::getParentNode)
.map((Node p) -> p instanceof LambdaExpr).orElse(false);
if (valid) {
return;
}
}
reportIllegalPosition(node, reporter);
return;
}
variableDeclarator.ifPresent(vd -> {
Optional<Node> variableDeclarationExpr = vd.getParentNode();
if (!variableDeclarationExpr.isPresent()) {
reportIllegalPosition(node, reporter);
return;
}
variableDeclarationExpr.ifPresent(vdeNode -> {
if (!(vdeNode instanceof VariableDeclarationExpr)) {
reportIllegalPosition(node, reporter);
return;
}
VariableDeclarationExpr vde = (VariableDeclarationExpr) vdeNode;
if (vde.getVariables().size() > 1) {
reporter.report(vde, "\"var\" only takes a single variable.");
}
Optional<Node> container = vdeNode.getParentNode();
if (!container.isPresent()) {
reportIllegalPosition(node, reporter);
return;
}
container.ifPresent(c -> {
boolean positionIsFine = c instanceof ForStmt || c instanceof ForeachStmt || c instanceof ExpressionStmt;
if (!positionIsFine) {
reportIllegalPosition(node, reporter);
}
// A local variable declaration ends up inside an ExpressionStmt.
if (c instanceof ExpressionStmt) {
if (!vd.getInitializer().isPresent()) {
reporter.report(node, "\"var\" needs an initializer.");
}
vd.getInitializer().ifPresent(initializer -> {
if (initializer instanceof NullLiteralExpr) {
reporter.report(node, "\"var\" cannot infer type from just null.");
}
if (initializer instanceof ArrayCreationExpr) {
reporter.report(node, "\"var\" cannot infer array types.");
}
});
}
});
});
});
}
private void reportIllegalPosition(VarType n, ProblemReporter reporter) {
reporter.report(n, "\"var\" is not allowed here.");
}
}
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