@Nullable
public static JetExpression getCalleeExpressionIfAny(@NotNull JetExpression expression) {
if (expression instanceof JetSimpleNameExpression) {
return expression;
}
if (expression instanceof JetCallElement) {
JetCallElement callExpression = (JetCallElement) expression;
return callExpression.getCalleeExpression();
}
if (expression instanceof JetQualifiedExpression) {
JetExpression selectorExpression =
((JetQualifiedExpression) expression).getSelectorExpression();
if (selectorExpression != null) {
return getCalleeExpressionIfAny(selectorExpression);
}
}
if (expression instanceof JetUnaryExpression) {
return ((JetUnaryExpression) expression).getOperationReference();
}
if (expression instanceof JetBinaryExpression) {
return ((JetBinaryExpression) expression).getOperationReference();
}
return null;
}