fix #6 - implicit class support

README.md

@@ -449,20 +449,18 @@ db.run(people(Senior))
 
 Infix is a very flexible mechanism to use non-supported features without having to use plain SQL queries. It allows insertion of arbitrary SQL strings within quotations.
 
-For instance, quill doesn't support the `FOR UPDATE` SQL feature. It can still be used through infix:
+For instance, quill doesn't support the `FOR UPDATE` SQL feature. It can still be used through infix and implicit classes:
 
 ```scala
-val forUpdate = quote {
-  new {
-    def apply[T](q: Query[T]) = infix"$q FOR UPDATE".as[Query[T]]
-  }
+implicit class ForUpdate[T](q: Query[T]) {
+  def forUpdate = quote(infix"$q FOR UPDATE".as[Query[T]])
 }
 
 val a = quote {
-  query[Person].filter(p => p.age < 18)
+  query[Person].filter(p => p.age < 18).forUpdate
 }
 
-db.run(forUpdate(a)) 
+db.run(a)
 // SELECT p.id, p.name, p.age FROM (SELECT * FROM Person p WHERE p.age < 18 FOR UPDATE) p
 ```
 
@@ -471,17 +469,15 @@ The `forUpdate` quotation can be reused for multiple queries.
 The same approach can be used for `RETURNING ID`:
 
 ```scala
-val returningId = quote {
-  new {
-    def apply[T](a: Action[T]) = infix"$a RETURNING ID".as[Action[T]]
-  }
+implicit class ReturningId[T](a: Action[T]) {
+  def returningId = quote(infix"$a RETURNING ID".as[Action[T]])
 }
 
 val a = quote {
-  query[Person].insert(_.name -> "John", _.age -> 21)
+  query[Person].insert(_.name -> "John", _.age -> 21).returningId
 }
 
-db.run(returningId(a))
+db.run(a)
 // INSERT INTO Person (name,age) VALUES ('John', 21) RETURNING ID
 ```
 

quill-core/src/main/scala/io/getquill/package.scala

@@ -10,6 +10,7 @@ package object getquill {
 
   def lift[T](v: T): T = v
 
+  def quote[T](body: Quoted[T]): Quoted[T] = macro Macro.doubleQuote[T]
   implicit def quote[T](body: T): Quoted[T] = macro Macro.quote[T]
   implicit def unquote[T](quoted: Quoted[T]): T = NonQuotedException()
 

quill-core/src/main/scala/io/getquill/quotation/FreeVariables.scala

@@ -44,7 +44,7 @@ case class FreeVariables(state: State)
 }
 
 object FreeVariables {
-  def apply(ast: Ast) =
+  def apply(ast: Ast): Set[Ident] =
     new FreeVariables(State(Set(), Set()))(ast) match {
       case (_, transformer) =>
         transformer.state.free

quill-core/src/main/scala/io/getquill/quotation/Parsing.scala

@@ -59,10 +59,9 @@ trait Parsing {
 
     case t if (t.tpe <:< c.weakTypeOf[Quoted[Any]]) =>
       unquote[Ast](t) match {
-        case Some(ast) if (!IsDynamic(ast)) => ast
+        case Some(ast) if (!IsDynamic(ast)) => Rebind(c)(t, ast, astParser(_))
         case other                          => Dynamic(t)
       }
-
   }
 
   val queryParser: Parser[Query] = Parser[Query] {
@@ -151,6 +150,7 @@ trait Parsing {
     case t: ValDef                        => Ident(t.name.decodedName.toString)
     case c.universe.Ident(TermName(name)) => Ident(name)
     case q"$i: $typ"                      => identParser(i)
+    case q"$cls.this.$i"                  => Ident(i.decodedName.toString)
     case c.universe.Bind(TermName(name), c.universe.Ident(termNames.WILDCARD)) =>
       Ident(name)
   }

quill-core/src/main/scala/io/getquill/quotation/Quotation.scala

@@ -1,11 +1,11 @@
 package io.getquill.quotation
 
+import io.getquill.util.Messages._
 import scala.annotation.StaticAnnotation
 import scala.reflect.ClassTag
 import scala.reflect.macros.whitebox.Context
 
 import io.getquill.ast._
-import io.getquill.util.Messages.RichContext
 
 trait Quoted[+T] {
   def ast: Ast
@@ -20,7 +20,6 @@ trait Quotation extends Parsing with Liftables with Unliftables {
 
   def quote[T: WeakTypeTag](body: Expr[T]) = {
     val ast = astParser(body.tree)
-    verifyFreeVariables(ast)
     q"""
       new ${c.weakTypeOf[Quoted[T]]} {
         @${c.weakTypeOf[QuotedAst]}($ast)
@@ -31,6 +30,13 @@ trait Quotation extends Parsing with Liftables with Unliftables {
     """
   }
 
+  def doubleQuote[T: WeakTypeTag](body: Expr[Quoted[T]]) = {
+    body.tree match {
+      case q"null" => c.fail("Can't quote null")
+      case tree    => q"io.getquill.unquote($tree)"
+    }
+  }
+
   protected def unquote[T](tree: Tree)(implicit ct: ClassTag[T]) =
     astTree(tree).flatMap(astUnliftable.unapply).map {
       case ast: T => ast
@@ -42,10 +48,4 @@ trait Quotation extends Parsing with Liftables with Unliftables {
       annotation <- method.annotations.headOption
       astTree <- annotation.tree.children.lastOption
     } yield (astTree)
-
-  private def verifyFreeVariables(ast: Ast) =
-    FreeVariables(ast).toList match {
-      case Nil  =>
-      case vars => c.fail(s"A quotation must not have references to variables outside its scope. Found: '${vars.mkString(", ")}' in '$ast'.")
-    }
 }

quill-core/src/main/scala/io/getquill/quotation/Rebind.scala

@@ -0,0 +1,34 @@
+package io.getquill.quotation
+
+import scala.reflect.macros.whitebox.Context
+import io.getquill.ast._
+import io.getquill.norm.BetaReduction
+
+object Rebind {
+
+  def apply(c: Context)(tree: c.Tree, ast: Ast, astParser: c.Tree => Ast) = {
+    import c.universe.{ Ident => _, _ }
+
+    def toIdent(s: Symbol) =
+      Ident(s.name.decodedName.toString)
+
+    def origRebind(conv: Tree, orig: Tree, astParser: Tree => Ast) = {
+      val paramSymbol = conv.symbol.asMethod.paramLists.flatten.head
+      (toIdent(paramSymbol) -> astParser(orig))
+    }
+
+    tree match {
+      case q"$conv($orig).$method" =>
+        BetaReduction(ast, origRebind(conv, orig, astParser))
+      case q"$conv($orig).$m(...$params)" =>
+        val method =
+          conv.symbol.asMethod.returnType.member(m)
+        val paramsIdents =
+          method.asMethod.paramLists.flatten.map(toIdent)
+        val paramsRebind =
+          paramsIdents.zip(params.flatten.map(astParser))
+        BetaReduction(ast, (origRebind(conv, orig, astParser) +: paramsRebind): _*)
+      case other => ast
+    }
+  }
+}

quill-core/src/main/scala/io/getquill/quotation/Unliftables.scala

@@ -2,6 +2,7 @@ package io.getquill.quotation
 
 import scala.reflect.macros.whitebox.Context
 
+import io.getquill.util.Messages._
 import io.getquill.ast._
 
 trait Unliftables {
@@ -32,7 +33,7 @@ trait Unliftables {
 
   implicit def listUnliftable[T](implicit u: Unliftable[T]): Unliftable[List[T]] = Unliftable[List[T]] {
     case q"$pack.Nil"                         => Nil
-    case q"$pack.List.apply[..$t](..$values)" => values.map(v => u.unapply(v)).flatten
+    case q"$pack.List.apply[..$t](..$values)" => values.map(v => u.unapply(v).getOrElse(c.fail(s"Can't unlift $v")))
   }
 
   implicit val binaryOperatorUnliftable: Unliftable[BinaryOperator] = Unliftable[BinaryOperator] {

quill-core/src/main/scala/io/getquill/source/SourceMacro.scala

@@ -1,13 +1,13 @@
 package io.getquill.source
 
 import scala.reflect.macros.whitebox.Context
-
 import io.getquill._
 import io.getquill.ast.{ Query => _, Action => _, _ }
 import io.getquill.norm.Normalize
 import io.getquill.quotation.Quotation
 import io.getquill.quotation.Quoted
 import io.getquill.util.Messages.RichContext
+import io.getquill.quotation.FreeVariables
 
 trait SourceMacro extends Quotation with ActionMacro with QueryMacro with ResolveSourceMacro {
   val c: Context
@@ -17,7 +17,7 @@ trait SourceMacro extends Quotation with ActionMacro with QueryMacro with Resolv
 
   def run[R, S, T](quoted: Expr[Quoted[T]])(implicit r: WeakTypeTag[R], s: WeakTypeTag[S], t: WeakTypeTag[T]): Tree = {
 
-    ast(quoted) match {
+    verifyFreeVariables(ast(quoted)) match {
 
       case ast if (t.tpe.typeSymbol.fullName.startsWith("scala.Function")) =>
         val bodyType = c.WeakTypeTag(t.tpe.typeArgs.takeRight(1).head)
@@ -51,4 +51,10 @@ trait SourceMacro extends Quotation with ActionMacro with QueryMacro with Resolv
 
   private def paramsTypes[T](implicit t: WeakTypeTag[T]) =
     t.tpe.typeArgs.dropRight(1)
+
+  private def verifyFreeVariables(ast: Ast) =
+    FreeVariables(ast).toList match {
+      case Nil  => ast
+      case vars => c.fail(s"A quotation must not have references to variables outside its scope. Found: '${vars.mkString(", ")}' in '$ast'.")
+    }
 }

quill-core/src/test/scala/io/getquill/ast/AstShowSpec.scala

@@ -321,10 +321,10 @@ class AstShowSpec extends Spec {
     }
     "null" in {
       val q = quote {
-        null
+        1 != null
       }
       (q.ast: Ast).show mustEqual
-        """null"""
+        """1 != null"""
     }
     "tuple" in {
       val q = quote {