Fleshed out basic implementations

1 files changed, 33 insertions, 0 deletions

diff --git a/build.sbt b/build.sbt
index 6836cb4f..6d412fc5 100644
--- a/build.sbt
+++ b/build.sbt
@@ -3,3 +3,36 @@ scalaVersion := "2.12.3"
 name := "hbt"
 
 organization := "com.lihaoyi"
+
+
+libraryDependencies += "com.lihaoyi" %% "sourcecode" % "0.1.4"
+
+sourceGenerators in Compile += Def.task {
+  val dir = (sourceManaged in Compile).value
+  val file = dir/"fasterparser"/"SequencerGen.scala"
+  // Only go up to 21, because adding the last element makes it 22
+  val tuples = (2 to 21).map{ i =>
+    val ts = (1 to i) map ("T" + _)
+    val chunks = (1 to i) map { n =>
+      s"t._$n"
+    }
+    val tsD = (ts :+ "D").mkString(",")
+    s"""
+          implicit def Sequencer$i[$tsD]: Sequencer[(${ts.mkString(", ")}), D, ($tsD)] =
+            Sequencer0((t, d) => (${chunks.mkString(", ")}, d))
+          """
+  }
+  val output = s"""
+          package hbt
+          trait SequencerGen[Sequencer[_, _, _]] extends LowestPriSequencer[Sequencer]{
+            protected[this] def Sequencer0[A, B, C](f: (A, B) => C): Sequencer[A, B, C]
+            ${tuples.mkString("\n")}
+          }
+          trait LowestPriSequencer[Sequencer[_, _, _]]{
+            protected[this] def Sequencer0[A, B, C](f: (A, B) => C): Sequencer[A, B, C]
+            implicit def Sequencer1[T1, T2]: Sequencer[T1, T2, (T1, T2)] = Sequencer0{case (t1, t2) => (t1, t2)}
+          }
+        """.stripMargin
+  IO.write(file, output)
+  Seq(file)
+}
\ No newline at end of file