From 3f5f6e309de9e327b2aed9cc3cac6f14e7e87c66 Mon Sep 17 00:00:00 2001
From: Mark Canlas <github@htmlism.com>
Date: Wed, 26 Aug 2020 03:54:02 -0400
Subject: [PATCH] mappings are derived from enums and bitfields

---
 .../com/htmlism/mos6502/dsl/Mapping.scala     | 48 +++++++++++++++++++
 .../mos6502/dsl/syntax/AsmDocSyntax.scala     | 44 ++---------------
 .../com/htmlism/mos6502/dsl/DslSpec.scala     | 44 -----------------
 3 files changed, 52 insertions(+), 84 deletions(-)

diff --git a/src/main/scala/com/htmlism/mos6502/dsl/Mapping.scala b/src/main/scala/com/htmlism/mos6502/dsl/Mapping.scala
index 3765844..1c10d29 100644
--- a/src/main/scala/com/htmlism/mos6502/dsl/Mapping.scala
+++ b/src/main/scala/com/htmlism/mos6502/dsl/Mapping.scala
@@ -25,3 +25,51 @@ trait Mapping[A] {
     */
   def comment(x: A): String
 }
+
+object Mapping {
+  implicit def mappingForBitField[A](implicit ev: BitField[A]): Mapping[A] =
+    new Mapping[A] {
+      private lazy val valueMap =
+        ev.all.toList
+          .zip(List.iterate(1, ev.all.size)(_ << 1))
+          .toMap
+
+      def definitionGroupComment: String =
+        ev.definitionGroupComment
+
+      def all: NonEmptyList[A] =
+        ev.all
+
+      def value(x: A): Int =
+        valueMap(x)
+
+      def label(x: A): String =
+        ev.label(x)
+
+      def comment(x: A): String =
+        "" // TODO
+    }
+
+  implicit def mappingForEnumAsm[A](implicit ev: EnumAsm[A]): Mapping[A] =
+    new Mapping[A] {
+      private lazy val valueMap =
+        ev.all.toList
+          .zip(List.iterate(0, ev.all.size)(_ + 1))
+          .toMap
+
+      def definitionGroupComment: String =
+        ev.comment
+
+      def all: NonEmptyList[A] =
+        ev.all
+
+      def value(x: A): Int =
+        valueMap(x)
+
+      def label(x: A): String =
+        ev.label(x)
+
+      def comment(x: A): String =
+        ev.comment(x)
+    }
+}
diff --git a/src/main/scala/com/htmlism/mos6502/dsl/syntax/AsmDocSyntax.scala b/src/main/scala/com/htmlism/mos6502/dsl/syntax/AsmDocSyntax.scala
index 213a0db..9781a40 100644
--- a/src/main/scala/com/htmlism/mos6502/dsl/syntax/AsmDocSyntax.scala
+++ b/src/main/scala/com/htmlism/mos6502/dsl/syntax/AsmDocSyntax.scala
@@ -25,47 +25,11 @@ trait AsmDocSyntax {
       .push(g.toGroup(s))
   }
 
-  def enum[A](implicit ctx: AsmDocumentContext, ev: EnumAsm[A]): Unit = {
-    val xs =
-      ev.all
-        .map(ev.label)
-        .toList
-        .zip(List.iterate(0, ev.all.size)(_ + 1))
+  def enum[A: EnumAsm: Mapping](implicit ctx: AsmDocumentContext): Unit =
+    mapping
 
-    val grp =
-      DefinitionGroup(
-        ev.comment,
-        xs
-          .map {
-            case (s, n) =>
-              Definition(s, n)
-          }
-      )
-
-    ctx
-      .push(grp)
-  }
-
-  def bitField[A](implicit ctx: AsmDocumentContext, ev: BitField[A]): Unit = {
-    val xs =
-      ev.all
-        .map(ev.label)
-        .toList
-        .zip(List.iterate(1, ev.all.size)(_ << 1))
-
-    val grp =
-      DefinitionGroup(
-        ev.definitionGroupComment,
-        xs
-          .map {
-            case (s, n) =>
-              Definition(s, n)
-          }
-      )
-
-    ctx
-      .push(grp)
-  }
+  def bitField[A: BitField: Mapping](implicit ctx: AsmDocumentContext): Unit =
+    mapping
 
   def mapping[A](implicit ctx: AsmDocumentContext, ev: Mapping[A]): Unit = {
     val xs =
diff --git a/src/test/scala/com/htmlism/mos6502/dsl/DslSpec.scala b/src/test/scala/com/htmlism/mos6502/dsl/DslSpec.scala
index 61892ed..c8368da 100644
--- a/src/test/scala/com/htmlism/mos6502/dsl/DslSpec.scala
+++ b/src/test/scala/com/htmlism/mos6502/dsl/DslSpec.scala
@@ -68,27 +68,6 @@ class DslSpec extends AnyFlatSpec with should.Matchers {
     )
   }
 
-  "mapping" should "compile" in {
-    val doc =
-      asmDoc { implicit ctx =>
-        mapping[TestDirection]
-      }
-
-    doc shouldEqual AsmDocument(
-      List(
-        DefinitionGroup(
-          "foo as a mapping",
-          List(
-            Definition("up", 0x77),
-            Definition("down", 0x61),
-            Definition("left", 0x73),
-            Definition("right", 0x64)
-          )
-        )
-      )
-    )
-  }
-
   "label" should "compile" in {
     val doc =
       asmDoc { implicit ctx =>
@@ -151,27 +130,4 @@ object TestDirection {
       def label(x: TestDirection): String =
         x.toString.toLowerCase
     }
-
-  implicit val mappingDirection: Mapping[TestDirection] =
-    new Mapping[TestDirection] {
-      def definitionGroupComment: String =
-        "foo as a mapping"
-
-      def all: NonEmptyList[TestDirection] =
-        NonEmptyList.of(Up, Down, Left, Right)
-
-      def value(x: TestDirection): Int =
-        x match {
-          case Up    => 0x77
-          case Down  => 0x61
-          case Left  => 0x73
-          case Right => 0x64
-        }
-
-      def label(x: TestDirection): String =
-        x.toString.toLowerCase
-
-      def comment(x: TestDirection): String =
-        x.toString
-    }
 }