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POScala Macros: Checking for a certain annotation
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copied!<p>Thanks to the answers to <a href="https://stackoverflow.com/q/17223213/397695">my previous question</a>, I was able to create a function macro such that it returns a <code>Map</code> that maps each field name to its value of a class, e.g.</p> <pre><code>... trait Model case class User (name: String, age: Int, posts: List[String]) extends Model { val numPosts: Int = posts.length ... def foo = "bar" ... } </code></pre> <p>So this command</p> <pre><code>val myUser = User("Foo", 25, List("Lorem", "Ipsum")) myUser.asMap </code></pre> <p>returns </p> <pre><code>Map("name" -> "Foo", "age" -> 25, "posts" -> List("Lorem", "Ipsum"), "numPosts" -> 2) </code></pre> <p>This is where <code>Tuple</code>s for the <code>Map</code> are generated (see Travis Brown's <a href="https://stackoverflow.com/a/17224392/397695">answer</a>):</p> <pre><code>... val pairs = weakTypeOf[T].declarations.collect { case m: MethodSymbol if m.isAccessor => val name = c.literal(m.name.decoded) val value = c.Expr(Select(model, m.name)) reify(name.splice -> value.splice).tree } ... </code></pre> <p>Now I want to ignore fields that have <code>@transient</code> annotation. How would I check if a method has a <code>@transient</code> annotation?</p> <p>I'm thinking of modifying the snippet above as</p> <pre><code>val pairs = weakTypeOf[T].declarations.collect { case m: MethodSymbol if m.isAccessor && !m.annotations.exists(???) => val name = c.literal(m.name.decoded) val value = c.Expr(Select(model, m.name)) reify(name.splice -> value.splice).tree } </code></pre> <p>but I can't find what I need to write in <code>exists</code> part. How would I get <code>@transient</code> as an <code>Annotation</code> so I could pass it there?</p> <p>Thanks in advance!</p>

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