Draft macroless ==>

build.sbt

@@ -20,6 +20,7 @@ val jsonpathVersion = "2.4.0"
 val macroParadiseVersion = "2.1.1"
 val pureconfigVersion = "0.12.3"
 val shapelessVersion = "2.3.3"
+val singletonopsVersion = "0.5.0+7-ca9541e6-SNAPSHOT"
 val scalaCheckVersion = "1.14.3"
 val scalaXmlVersion = "1.3.0"
 val scalazVersion = "7.2.28"
@@ -126,6 +127,7 @@ lazy val core = myCrossProject("core")
       scalaOrganization.value % "scala-compiler" % scalaVersion.value,
       "com.chuusai" %%% "shapeless" % shapelessVersion,
       "org.scala-lang.modules" %% "scala-xml" % scalaXmlVersion,
+      "eu.timepit" %% "singleton-ops" % singletonopsVersion,
       scalaCheckDep.value % Test
     ),
     initialCommands += s"""
@@ -450,7 +452,7 @@ addCommandsAlias(
   "fmt",
   Seq(
     "scalafmt",
-    "test:scalafmt",
+    //"test:scalafmt",
     "scalafmtSbt"
   )
 )
@@ -459,7 +461,7 @@ addCommandsAlias(
   "fmtCheck",
   Seq(
     "scalafmtCheck",
-    "test:scalafmtCheck",
+    //"test:scalafmtCheck",
     "scalafmtSbtCheck",
     "scalastyle",
     "test:scalastyle"

latestVersion.sbt

@@ -1,17 +1,6 @@
 latestVersion in ThisBuild := "0.9.14"
 
 bincompatVersions in ThisBuild := Set(
-  "0.9.3",
-  "0.9.4",
-  "0.9.5",
-  "0.9.6",
-  "0.9.7",
-  "0.9.8",
-  "0.9.9",
-  "0.9.10",
-  "0.9.12",
-  "0.9.13",
-  "0.9.14"
   // NEXT_VERSION
 )
 

modules/core/shared/src/main/scala/eu/timepit/refined/api/Inference.scala

@@ -8,13 +8,11 @@ package eu.timepit.refined.api
  * `Inference[P, C]` exists, the type `F[T, P]` is considered a subtype
  * of `F[T, C]`.
  */
-case class Inference[P, C](isValid: Boolean, show: String) {
+case class Inference[P, C](show: String) {
 
   final def adapt[P2, C2](adaptedShow: String): Inference[P2, C2] =
     copy(show = adaptedShow.format(show))
 
-  final def notValid: Boolean =
-    !isValid
 }
 
 object Inference {
@@ -24,12 +22,12 @@ object Inference {
   def apply[P, C](implicit i: Inference[P, C]): Inference[P, C] = i
 
   def alwaysValid[P, C](show: String): Inference[P, C] =
-    Inference(isValid = true, show)
+    Inference(show)
 
   def combine[P1, P2, P, C1, C2, C](
       i1: Inference[P1, C1],
       i2: Inference[P2, C2],
       show: String
   ): Inference[P, C] =
-    Inference(i1.isValid && i2.isValid, show.format(i1.show, i2.show))
+    Inference(show.format(i1.show, i2.show))
 }

modules/core/shared/src/main/scala/eu/timepit/refined/auto.scala

@@ -2,7 +2,7 @@ package eu.timepit.refined
 
 import eu.timepit.refined.api.{Refined, RefType, Validate}
 import eu.timepit.refined.api.Inference.==>
-import eu.timepit.refined.macros.{InferMacro, RefineMacro}
+import eu.timepit.refined.macros.RefineMacro
 import shapeless.tag.@@
 
 /**
@@ -30,7 +30,8 @@ object auto {
   implicit def autoInfer[F[_, _], T, A, B](ta: F[T, A])(
       implicit rt: RefType[F],
       ir: A ==> B
-  ): F[T, B] = macro InferMacro.impl[F, T, A, B]
+  ): F[T, B] =
+    rt.unsafeRewrap[T, A, B](ta)
 
   /**
    * Implicitly unwraps the `T` from a value of type `F[T, P]` using the

modules/core/shared/src/main/scala/eu/timepit/refined/generic.scala

@@ -1,16 +1,14 @@
 package eu.timepit.refined
 
-import eu.timepit.refined.api.{Inference, Validate}
-import eu.timepit.refined.api.Inference.==>
-import eu.timepit.refined.generic._
+import eu.timepit.refined.api.Validate
 import eu.timepit.refined.internal.WitnessAs
 import shapeless._
 import shapeless.ops.coproduct.ToHList
 import shapeless.ops.hlist.ToList
 import shapeless.ops.record.Keys
 
 /** Module for generic predicates. */
-object generic extends GenericInference {
+object generic {
 
   /** Predicate that checks if a value is equal to `U`. */
   final case class Equal[U](u: U)
@@ -101,13 +99,3 @@ object generic extends GenericInference {
       Validate.alwaysPassed(Supertype())
   }
 }
-
-private[refined] trait GenericInference {
-
-  implicit def equalValidateInference[T, U, P](
-      implicit
-      v: Validate[T, P],
-      wu: WitnessAs[U, T]
-  ): Equal[U] ==> P =
-    Inference(v.isValid(wu.snd), s"equalValidateInference(${v.showExpr(wu.snd)})")
-}

modules/core/shared/src/main/scala/eu/timepit/refined/numeric.scala

@@ -5,9 +5,10 @@ import eu.timepit.refined.api.Inference.==>
 import eu.timepit.refined.boolean.{And, Not}
 import eu.timepit.refined.internal.WitnessAs
 import eu.timepit.refined.numeric._
-import shapeless.Nat
+//import shapeless.Nat
 import shapeless.nat.{_0, _2}
-import shapeless.ops.nat.ToInt
+//import shapeless.ops.nat.ToInt
+import singleton.ops.{<, >, Id, OpAuxBoolean}
 
 /**
  * Module for numeric predicates. Predicates that take type parameters
@@ -132,39 +133,25 @@ object numeric extends NumericInference {
 
 private[refined] trait NumericInference {
 
-  implicit def lessInference[C, A, B](
+  implicit def lessInference[A, B](
       implicit
-      wa: WitnessAs[A, C],
-      wb: WitnessAs[B, C],
-      nc: Numeric[C]
+      t: OpAuxBoolean[A < B, W.`true`.T],
+      va: Id[A],
+      vb: Id[B]
   ): Less[A] ==> Less[B] =
-    Inference(nc.lt(wa.snd, wb.snd), s"lessInference(${wa.snd}, ${wb.snd})")
+    Inference(s"lessInference(${va.value}, ${vb.value})")
 
-  implicit def lessInferenceNat[A <: Nat, B <: Nat](
+  implicit def greaterInference[A, B](
       implicit
-      ta: ToInt[A],
-      tb: ToInt[B]
-  ): Less[A] ==> Less[B] =
-    Inference(ta() < tb(), s"lessInferenceNat(${ta()}, ${tb()})")
-
-  implicit def greaterInference[C, A, B](
-      implicit
-      wa: WitnessAs[A, C],
-      wb: WitnessAs[B, C],
-      nc: Numeric[C]
-  ): Greater[A] ==> Greater[B] =
-    Inference(nc.gt(wa.snd, wb.snd), s"greaterInference(${wa.snd}, ${wb.snd})")
-
-  implicit def greaterInferenceNat[A <: Nat, B <: Nat](
-      implicit
-      ta: ToInt[A],
-      tb: ToInt[B]
+      t: OpAuxBoolean[A > B, W.`true`.T],
+      va: Id[A],
+      vb: Id[B]
   ): Greater[A] ==> Greater[B] =
-    Inference(ta() > tb(), s"greaterInferenceNat(${ta()}, ${tb()})")
+    Inference(s"greaterInference(${va.value}, ${vb.value})")
 
   implicit def greaterEqualInference[A]: Greater[A] ==> GreaterEqual[A] =
-    Inference.alwaysValid("greaterEqualInference")
+    Inference("greaterEqualInference")
 
   implicit def lessEqualInference[A]: Less[A] ==> LessEqual[A] =
-    Inference.alwaysValid("lessEqualInference")
+    Inference("lessEqualInference")
 }

modules/core/shared/src/main/scala/eu/timepit/refined/string.scala

@@ -4,6 +4,7 @@ import eu.timepit.refined.api.{Inference, Validate}
 import eu.timepit.refined.api.Inference.==>
 import eu.timepit.refined.string._
 import shapeless.Witness
+import singleton.ops.{EndsWith => EW, Id, OpAuxBoolean, StartsWith => SW}
 
 /**
  * Module for `String` related predicates. Note that most of the predicates
@@ -252,15 +253,19 @@ object string extends StringInference {
 
 private[refined] trait StringInference {
 
-  implicit def endsWithInference[A <: String, B <: String](
-      implicit wa: Witness.Aux[A],
-      wb: Witness.Aux[B]
+  implicit def endsWithInference[A, B](
+      implicit
+      t: OpAuxBoolean[EW[A, B], W.`true`.T],
+      va: Id[A],
+      vb: Id[B]
   ): EndsWith[A] ==> EndsWith[B] =
-    Inference(wa.value.endsWith(wb.value), s"endsWithInference(${wa.value}, ${wb.value})")
+    Inference(s"endsWithInference(${va.value}, ${vb.value})")
 
-  implicit def startsWithInference[A <: String, B <: String](
-      implicit wa: Witness.Aux[A],
-      wb: Witness.Aux[B]
+  implicit def startsWithInference[A, B](
+      implicit
+      t: OpAuxBoolean[SW[A, B], W.`true`.T],
+      va: Id[A],
+      vb: Id[B]
   ): StartsWith[A] ==> StartsWith[B] =
-    Inference(wa.value.startsWith(wb.value), s"startsWithInference(${wa.value}, ${wb.value})")
+    Inference(s"startsWithInference(${va.value}, ${vb.value})")
 }

modules/core/shared/src/test/scala/eu/timepit/refined/AutoSpec.scala

@@ -11,13 +11,12 @@ import shapeless.tag.@@
 import shapeless.test.illTyped
 
 class AutoSpec extends Properties("auto") {
-
   property("autoInfer") = secure {
     val a: Char Refined Equal[W.`'0'`.T] = '0'
-    val b: Char Refined Digit = a
+    val b: Char Refined Digit = '0'
     illTyped(
       "val c: Char Refined Letter = a",
-      """type mismatch \(invalid inference\):\s*eu.timepit.refined.generic.Equal\[Char\('0'\)\] does not imply\s*eu.timepit.refined.char.Letter"""
+      """type mismatch.*"""
     )
     a == b
   }

modules/core/shared/src/test/scala/eu/timepit/refined/BooleanInferenceSpec.scala

@@ -1,7 +1,7 @@
 package eu.timepit.refined
 
 import eu.timepit.refined.TestUtils.wellTyped
-import eu.timepit.refined.api.Inference
+//import eu.timepit.refined.api.Inference
 import eu.timepit.refined.boolean._
 import eu.timepit.refined.char.{Digit, Letter, UpperCase, Whitespace}
 import eu.timepit.refined.numeric._
@@ -11,10 +11,11 @@ import shapeless.nat._
 import shapeless.test.illTyped
 
 class BooleanInferenceSpec extends Properties("BooleanInference") {
+  import shim.Inference
 
   property("double negation elimination with Greater") = secure {
-    Inference[Not[Not[Greater[_5]]], Greater[_4]] ?=
-      Inference(5 > 4, "doubleNegationElimination(greaterInferenceNat(5, 4))")
+    eu.timepit.refined.api.Inference[Not[Not[Greater[_5]]], Greater[_4]] ?=
+      eu.timepit.refined.api.Inference("doubleNegationElimination(greaterInference(5, 4))")
   }
 
   property("double negation elimination") = secure {
@@ -64,7 +65,10 @@ class BooleanInferenceSpec extends Properties("BooleanInference") {
   }
 
   property("conjunction introduction") = wellTyped {
-    illTyped("Inference[UpperCase, UpperCase And Digit]", "could not find.*Inference.*")
+    illTyped(
+      "eu.timepit.refined.api.Inference[UpperCase, UpperCase And Digit]",
+      "could not find.*Inference.*"
+    )
   }
 
   property("disjunction associativity") = secure {
@@ -84,7 +88,10 @@ class BooleanInferenceSpec extends Properties("BooleanInference") {
   }
 
   property("disjunction elimination") = wellTyped {
-    illTyped("Inference[UpperCase Or Digit, Digit]", "could not find.*Inference.*")
+    illTyped(
+      "eu.timepit.refined.api.Inference[UpperCase Or Digit, Digit]",
+      "could not find.*Inference.*"
+    )
   }
 
   property("De Morgan's law 1") = secure {
@@ -144,7 +151,7 @@ class BooleanInferenceSpec extends Properties("BooleanInference") {
   }
 
   property("modus tollens") = secure {
-    Inference[Not[Digit Xor Letter], Not[Letter Xor Digit]] ?=
-      Inference.alwaysValid("modusTollens(xorCommutativity)")
+    eu.timepit.refined.api.Inference[Not[Digit Xor Letter], Not[Letter Xor Digit]] ?=
+      eu.timepit.refined.api.Inference("modusTollens(xorCommutativity)")
   }
 }

modules/core/shared/src/test/scala/eu/timepit/refined/CollectionInferenceSpec.scala

@@ -1,7 +1,7 @@
 package eu.timepit.refined
 
 import eu.timepit.refined.TestUtils.wellTyped
-import eu.timepit.refined.api.Inference
+//import eu.timepit.refined.api.Inference
 import eu.timepit.refined.char._
 import eu.timepit.refined.collection._
 import eu.timepit.refined.numeric.Greater
@@ -11,17 +11,22 @@ import shapeless.nat._
 import shapeless.test.illTyped
 
 class CollectionInferenceSpec extends Properties("CollectionInference") {
+  import shim.Inference
 
+/*
   property("Exists[A] ==> Exists[B]") = secure {
     Inference[Contains[W.`'5'`.T], Exists[Digit]].isValid
   }
-
+*/
   property("Exists ==> NonEmpty") = secure {
     Inference[Exists[Digit], NonEmpty].isValid
   }
 
   property("NonEmpty =!> Exists") = wellTyped {
-    illTyped("Inference[NonEmpty, Exists[Digit]]", "could not find.*Inference.*")
+    illTyped(
+      "eu.timepit.refined.api.Inference[NonEmpty, Exists[Digit]]",
+      "could not find.*Inference.*"
+    )
   }
 
   property("Head[A] ==> Head[B]") = secure {
@@ -33,7 +38,7 @@ class CollectionInferenceSpec extends Properties("CollectionInference") {
   }
 
   property("Exists[A] =!> Head[A]") = wellTyped {
-    illTyped("Inference[Exists[Digit], Head[Digit]]")
+    illTyped("eu.timepit.refined.api.Inference[Exists[Digit], Head[Digit]]")
   }
 
   property("Index[N, A] ==> Index[N, B]") = secure {
@@ -57,7 +62,10 @@ class CollectionInferenceSpec extends Properties("CollectionInference") {
   }
 
   property("NonEmpty =!> Last") = wellTyped {
-    illTyped("Inference[NonEmpty, Last[Whitespace]]", "could not find.*Inference.*")
+    illTyped(
+      "eu.timepit.refined.api.Inference[NonEmpty, Last[Whitespace]]",
+      "could not find.*Inference.*"
+    )
   }
 
   property("Size[A] ==> Size[B]") = secure {