Iterable support

README.md

@@ -1,4 +1,4 @@
-Sauron [![Circle CI](https://img.shields.io/circleci/project/pathikrit/sauron.svg)](https://circleci.com/gh/pathikrit/sauron) [![Download](https://api.bintray.com/packages/pathikrit/maven/sauron/images/download.svg)](https://bintray.com/pathikrit/maven/sauron/_latestVersion)
+Sauron [![Circle CI](https://img.shields.io/circleci/project/pathikrit/sauron/master.svg)](https://circleci.com/gh/pathikrit/sauron) [![Download](https://api.bintray.com/packages/pathikrit/maven/sauron/images/download.svg)](https://bintray.com/pathikrit/maven/sauron/_latestVersion)
 --------
 
 Lightweight [lens library](http://stackoverflow.com/questions/3900307/cleaner-way-to-update-nested-structures) in less than [50-lines of Scala](src/main/scala/com/github/pathikrit/sauron/package.scala):
@@ -11,6 +11,7 @@ val person = Person(Address(Street("1 Functional Rd.")))
 
 import com.github.pathikrit.sauron._
 
+lens(person)(_.address.street.name).setTo("1 Objective Rd.")
 lens(person)(_.address.street.name)(_.toUpperCase)
 ```
 
@@ -23,11 +24,6 @@ person.copy(address = person.address.copy(
 )
 ```
 
-**Simple setters**:
-```scala
-lens(person)(_.address.street.name).setTo("1 Objective Rd.")
-```
-
 **Reusable lenses**:
 ```scala
 val f1 = lens(person)(_.address.street.name)

src/main/scala/com/github/pathikrit/sauron/package.scala

@@ -1,5 +1,6 @@
 package com.github.pathikrit
 
+import scala.annotation.compileTimeOnly
 import scala.reflect.macros.blackbox
 
 package object sauron {
@@ -14,8 +15,12 @@ package object sauron {
   def lensImpl[A, B](c: blackbox.Context)(obj: c.Expr[A])(path: c.Expr[A => B]): c.Tree = {
     import c.universe._
 
+    case class PathElement(term: c.TermName, isEach: Boolean)
+
     def split(accessor: c.Tree): List[c.TermName] = accessor match {      // (_.p.q.r) -> List(p, q, r)
       case q"$pq.$r" => split(pq) :+ r
+      case q"$tpName[..$_]($r)" if tpName.toString.contains("sauron.`package`.IterableOps") =>
+        c.abort(c.enclosingPosition, s"Hooray: $accessor, $r")
       case _: Ident => Nil
       case _ => c.abort(c.enclosingPosition, s"Unsupported path element: $accessor")
     }
@@ -42,4 +47,12 @@ package object sauron {
   implicit class UpdaterOps[A, B](val f: Updater[A, B]) extends AnyVal {
     def setTo(v: B): A = f(_ => v)
   }
+
+  implicit class IterableOps[A](val l: Iterable[A]) extends AnyVal {
+    @compileTimeOnly(IterableOps.errorMsg) def each: A = throw new UnsupportedOperationException(IterableOps.errorMsg)
+  }
+
+  object IterableOps {
+    def errorMsg = ".each can only be used within sauron's lens macro"
+  }
 }

src/test/scala/com/github/pathikrit/sauron/suites/SauronSuite.scala

@@ -3,14 +3,19 @@ package com.github.pathikrit.sauron.suites
 import org.scalatest._, Matchers._
 
 class SauronSuite extends FunSuite {
-  test("lensing") {
-    import com.github.pathikrit.sauron._
+  import com.github.pathikrit.sauron._
+
+  case class A(a1: String, a2: B)
+  case class B(b1: Option[Int], b2: List[C], b3: C)
+  case class C(c1: Int, c2: List[D], c3: D)
+  case class D(d1: List[String], d2: Option[Boolean], d3: A, d4: D)
 
+  test("lensing") {
     case class Person(name: String, address: Address)
-    case class Address(street: Street, street2: Option[Street], city: String, state: String, zip: String, country: String)
+    case class Address(street: Street, street2: List[Street], city: String, state: String, zip: String, country: Option[String])
     case class Street(name: String)
 
-    val p1 = Person("Rick", Address(Street("Rock St"), None, "MtV", "CA", "94041", "USA"))
+    val p1 = Person("Rick", Address(Street("Rock St"), Nil, "MtV", "CA", "94041", Some("USA")))
     def addHouseNumber(number: Int)(st: String) = s"$number $st"
 
     val p2 = lens(p1)(_.address.street.name)(addHouseNumber(1901))
@@ -37,6 +42,24 @@ class SauronSuite extends FunSuite {
 
     val p5: Person = lens(p1)(_.address.street.name).setTo("Rick St")
     p5.address.street.name shouldEqual "Rick St"
+    //lens(p1)(_.address.street2.each.name)(_.toUpperCase)
+
+    def f(s: String) = s.toUpperCase
+
+    p1.copy(
+      address = p1.address.copy(
+        street2 = p1.address.street2.map(el => el.copy(name = f(el.name)))
+      )
+    )
+
+    p1.copy(
+      address = p1.address.copy(
+        country = p1.address.country.map(_.toUpperCase)
+      )
+    )
+
+    // should not typecheck
+
 
     "lens(p1)(_.address.zip)(_.toUpperCase)" should compile
     "lens(p1)(_.address.zip.length)(_ + 1)" shouldNot compile