Add `{% docstring "scala.collection.Seq" %}` support

4 files changed, 42 insertions, 2 deletions

diff --git a/doc-tool/src/dotty/tools/dottydoc/staticsite/DefaultParams.scala b/doc-tool/src/dotty/tools/dottydoc/staticsite/DefaultParams.scala
index 5bed79869..cc1f8862f 100644
--- a/doc-tool/src/dotty/tools/dottydoc/staticsite/DefaultParams.scala
+++ b/doc-tool/src/dotty/tools/dottydoc/staticsite/DefaultParams.scala
@@ -2,13 +2,14 @@ package dotty.tools
 package dottydoc
 package staticsite
 
-import model.{ Entity, NonEntity }
+import model.{ Entity, Package, NonEntity }
 
 import java.util.{ HashMap, List => JList, Map => JMap }
 import scala.collection.JavaConverters._
 
 case class DefaultParams(
   docs: JList[_],
+  originalDocs: Map[String, Package],
   page: PageInfo,
   site: SiteInfo,
   sidebar: Sidebar,
@@ -19,6 +20,8 @@ case class DefaultParams(
   def toMap: Map[String, AnyRef] = Map(
     "docs" -> docs,
 
+    "originalDocs" -> originalDocs,
+
     "page" -> Map(
       "url" -> page.url,
       "date" -> page.date,
diff --git a/doc-tool/src/dotty/tools/dottydoc/staticsite/LiquidTemplate.scala b/doc-tool/src/dotty/tools/dottydoc/staticsite/LiquidTemplate.scala
index ef7a59f1c..e5873d1a9 100644
--- a/doc-tool/src/dotty/tools/dottydoc/staticsite/LiquidTemplate.scala
+++ b/doc-tool/src/dotty/tools/dottydoc/staticsite/LiquidTemplate.scala
@@ -29,5 +29,6 @@ case class LiquidTemplate(contents: String) extends ResourceFinder {
             .`with`(ResourceInclude(params, includes))
             .`with`(RenderReference(params))
             .`with`(RenderTitle(params))
+            .`with`(Docstring(params))
             .render(toJavaMap(params))
 }
diff --git a/doc-tool/src/dotty/tools/dottydoc/staticsite/Site.scala b/doc-tool/src/dotty/tools/dottydoc/staticsite/Site.scala
index 3fb5dad24..de16293a1 100644
--- a/doc-tool/src/dotty/tools/dottydoc/staticsite/Site.scala
+++ b/doc-tool/src/dotty/tools/dottydoc/staticsite/Site.scala
@@ -132,7 +132,7 @@ case class Site(val root: JFile, val projectTitle: String, val documentation: Ma
       "../" * (assetLen - rootLen - 1 + additionalDepth) + "."
     }
 
-    DefaultParams(docs, PageInfo(pathFromRoot), SiteInfo(baseUrl, projectTitle, Array()), sidebar)
+    DefaultParams(docs, documentation, PageInfo(pathFromRoot), SiteInfo(baseUrl, projectTitle, Array()), sidebar)
   }
 
   private def createOutput(outDir: JFile)(op: => Unit): this.type = {
diff --git a/doc-tool/src/dotty/tools/dottydoc/staticsite/tags.scala b/doc-tool/src/dotty/tools/dottydoc/staticsite/tags.scala
index fe6a05bbc..7f85846dc 100644
--- a/doc-tool/src/dotty/tools/dottydoc/staticsite/tags.scala
+++ b/doc-tool/src/dotty/tools/dottydoc/staticsite/tags.scala
@@ -9,6 +9,7 @@ import liqp.TemplateContext
 import liqp.nodes.LNode
 
 import java.util.{ Map => JMap }
+import model._
 
 object tags {
 
@@ -168,4 +169,39 @@ object tags {
         case _ => null
       }
   }
+
+  /** Allows the extraction of docstrings from the given path. E.g:
+    *
+    * ```html
+    * {% docstring "scala.collection.Seq" %}
+    * ```
+    *
+    * In Scaladoc, objects are denoted by a name ending in '$'. This means that
+    * a path that goes through, or targets an object need to appropriately
+    * intersperse these, e.g:
+    *
+    * ```html
+    * {% docstring "scala.collection.Seq$" %}
+    * ```
+    */
+  case class Docstring(params: Map[String, AnyRef]) extends Tag("docstring") {
+    private def find(xs: List[String], ent: Entity with Members): Option[Entity] = xs match {
+      case Nil => None
+      case x :: Nil =>
+        ent.members collect { case e: Entity with Members => e } find (_.path.last == x)
+      case x :: xs =>
+        ent.members collect { case e: Entity with Members => e } find (_.path.last == x) flatMap (find(xs, _))
+    }
+
+    override def render(ctx: TemplateContext, nodes: LNode*): AnyRef = nodes(0).render(ctx) match {
+      case query: String =>
+        params.get("originalDocs").collect {
+          case docs: Map[String, Package] @unchecked =>
+            val search = query.split("\\.")
+            if (search.isEmpty || !docs.contains(search.head)) null
+            else find(search.tail.toList, docs(search.head)).flatMap(_.comment.map(_.body)).getOrElse(null)
+        }.getOrElse(null)
+      case _ => null
+    }
+  }
 }