Merge pull request #372 from ucb-bar/onetrueliteral

Standardize the One True Way of specifying literals

6 files changed, 151 insertions, 139 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala b/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
index de7af462..8fdcb260 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Aggregate.scala
@@ -123,10 +123,10 @@ object Vec {
   /** Truncate an index to implement modulo-power-of-2 addressing. */
   private[core] def truncateIndex(idx: UInt, n: Int)(implicit sourceInfo: SourceInfo): UInt = {
     val w = BigInt(n-1).bitLength
-    if (n <= 1) UInt(0)
+    if (n <= 1) 0.U
     else if (idx.width.known && idx.width.get <= w) idx
     else if (idx.width.known) idx(w-1,0)
-    else (idx | UInt(0, w))(w-1,0)
+    else (idx | 0.U(w))(w-1,0)
   }
 }
 
@@ -249,7 +249,7 @@ trait VecLike[T <: Data] extends collection.IndexedSeq[T] with HasId {
   // IndexedSeq has its own hashCode/equals that we must not use
   override def hashCode: Int = super[HasId].hashCode
   override def equals(that: Any): Boolean = super[HasId].equals(that)
-  
+
   @deprecated("Use Vec.apply instead", "chisel3")
   def read(idx: UInt): T
 
@@ -261,14 +261,14 @@ trait VecLike[T <: Data] extends collection.IndexedSeq[T] with HasId {
   def forall(p: T => Bool): Bool = macro SourceInfoTransform.pArg
 
   def do_forall(p: T => Bool)(implicit sourceInfo: SourceInfo): Bool =
-    (this map p).fold(Bool(true))(_ && _)
+    (this map p).fold(true.B)(_ && _)
 
   /** Outputs true if p outputs true for at least one element.
     */
   def exists(p: T => Bool): Bool = macro SourceInfoTransform.pArg
 
   def do_exists(p: T => Bool)(implicit sourceInfo: SourceInfo): Bool =
-    (this map p).fold(Bool(false))(_ || _)
+    (this map p).fold(false.B)(_ || _)
 
   /** Outputs true if the vector contains at least one element equal to x (using
     * the === operator).
@@ -288,7 +288,7 @@ trait VecLike[T <: Data] extends collection.IndexedSeq[T] with HasId {
   /** Helper function that appends an index (literal value) to each element,
     * useful for hardware generators which output an index.
     */
-  private def indexWhereHelper(p: T => Bool) = this map p zip (0 until length).map(i => UInt(i))
+  private def indexWhereHelper(p: T => Bool) = this map p zip (0 until length).map(i => i.asUInt)
 
   /** Outputs the index of the first element for which p outputs true.
     */
@@ -388,7 +388,7 @@ class Bundle extends Aggregate {
   private[chisel3] lazy val flatten = namedElts.flatMap(_._2.flatten)
   private[chisel3] override def _onModuleClose: Unit = // scalastyle:ignore method.name
     for ((name, elt) <- namedElts) { elt.setRef(this, _namespace.name(name)) }
-    
+
   private[chisel3] final def allElements: Seq[Element] = namedElts.flatMap(_._2.allElements)
 
   override def cloneType : this.type = {
diff --git a/chiselFrontend/src/main/scala/chisel3/core/Bits.scala b/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
index 82b60a4c..354512e1 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
@@ -92,7 +92,7 @@ sealed abstract class Bits(width: Width, override val litArg: Option[LitArg])
       Builder.error(s"Negative bit indices are illegal (got $x)")
     }
     if (isLit()) {
-      Bool(((litValue() >> x.toInt) & 1) == 1)
+      (((litValue() >> x.toInt) & 1) == 1).asBool
     } else {
       Binding.checkSynthesizable(this, s"'this' ($this)")
       pushOp(DefPrim(sourceInfo, Bool(), BitsExtractOp, this.ref, ILit(x), ILit(x)))
@@ -134,7 +134,7 @@ sealed abstract class Bits(width: Width, override val litArg: Option[LitArg])
     }
     val w = x - y + 1
     if (isLit()) {
-      UInt((litValue >> y) & ((BigInt(1) << w) - 1), w)
+      ((litValue >> y) & ((BigInt(1) << w) - 1)).asUInt(w.W)
     } else {
       Binding.checkSynthesizable(this, s"'this' ($this)")
       pushOp(DefPrim(sourceInfo, UInt(Width(w)), BitsExtractOp, this.ref, ILit(x), ILit(y)))
@@ -304,11 +304,6 @@ sealed abstract class Bits(width: Width, override val litArg: Option[LitArg])
   final def toPrintable: Printable = Decimal(this)
 }
 
-/** Provides a set of operations to create UInt types and literals.
-  * Identical in functionality to the UInt companion object.
-  */
-object Bits extends UIntFactory
-
 // REVIEW TODO: Further discussion needed on what Num actually is.
 /** Abstract trait defining operations available on numeric-like wire data
   * types.
@@ -408,14 +403,14 @@ sealed class UInt private[core] (width: Width, lit: Option[ULit] = None)
   private[chisel3] def toType = s"UInt$width"
 
   override private[chisel3] def fromInt(value: BigInt, width: Int): this.type =
-    UInt(value, width).asInstanceOf[this.type]
+    value.asUInt(width.W).asInstanceOf[this.type]
 
   // TODO: refactor to share documentation with Num or add independent scaladoc
   final def unary_- (): UInt = macro SourceInfoTransform.noArg
   final def unary_-% (): UInt = macro SourceInfoTransform.noArg
 
-  def do_unary_- (implicit sourceInfo: SourceInfo) : UInt = UInt(0) - this
-  def do_unary_-% (implicit sourceInfo: SourceInfo): UInt = UInt(0) -% this
+  def do_unary_- (implicit sourceInfo: SourceInfo) : UInt = 0.U - this
+  def do_unary_-% (implicit sourceInfo: SourceInfo): UInt = 0.U -% this
 
   override def do_+ (that: UInt)(implicit sourceInfo: SourceInfo): UInt = this +% that
   override def do_- (that: UInt)(implicit sourceInfo: SourceInfo): UInt = this -% that
@@ -463,8 +458,8 @@ sealed class UInt private[core] (width: Width, lit: Option[ULit] = None)
   final def andR(): Bool = macro SourceInfoTransform.noArg
   final def xorR(): Bool = macro SourceInfoTransform.noArg
 
-  def do_orR(implicit sourceInfo: SourceInfo): Bool = this != UInt(0)
-  def do_andR(implicit sourceInfo: SourceInfo): Bool = ~this === UInt(0)
+  def do_orR(implicit sourceInfo: SourceInfo): Bool = this != 0.U
+  def do_andR(implicit sourceInfo: SourceInfo): Bool = ~this === 0.U
   def do_xorR(implicit sourceInfo: SourceInfo): Bool = redop(sourceInfo, XorReduceOp)
 
   override def do_< (that: UInt)(implicit sourceInfo: SourceInfo): Bool = compop(sourceInfo, LessOp, that)
@@ -483,7 +478,7 @@ sealed class UInt private[core] (width: Width, lit: Option[ULit] = None)
 
   final def unary_! () : Bool = macro SourceInfoTransform.noArg
 
-  def do_unary_! (implicit sourceInfo: SourceInfo) : Bool = this === UInt(0, 1)
+  def do_unary_! (implicit sourceInfo: SourceInfo) : Bool = this === 0.U(1)
 
   override def do_<< (that: Int)(implicit sourceInfo: SourceInfo): UInt =
     binop(sourceInfo, UInt(this.width + that), ShiftLeftOp, that)
@@ -501,7 +496,7 @@ sealed class UInt private[core] (width: Width, lit: Option[ULit] = None)
   final def bitSet(off: UInt, dat: Bool): UInt = macro UIntTransform.bitset
 
   def do_bitSet(off: UInt, dat: Bool)(implicit sourceInfo: SourceInfo): UInt = {
-    val bit = UInt(1, 1) << off
+    val bit = 1.U(1) << off
     Mux(dat, this | bit, ~(~this | bit))
   }
 
@@ -532,89 +527,35 @@ sealed class UInt private[core] (width: Width, lit: Option[ULit] = None)
 }
 
 // This is currently a factory because both Bits and UInt inherit it.
-private[core] sealed trait UIntFactory {
+trait UIntFactory {
   /** Create a UInt type with inferred width. */
   def apply(): UInt = apply(Width())
   /** Create a UInt port with specified width. */
   def apply(width: Width): UInt = new UInt(width)
-  /** Create a UInt with a specified width - compatibility with Chisel2. */
-  def width(width: Int): UInt = apply(Width(width))
-  /** Create a UInt port with specified width. */
-  def width(width: Width): UInt = new UInt(width)
-  /** Create a UInt literal with fixed width. */
-  def apply(value: BigInt, width: Int): UInt = Lit(value, Width(width))
-  /** Create a UInt literal with inferred width. */
-  def apply(n: String): UInt = Lit(n)
-   /** Create a UInt literal with fixed width. */
-  def apply(n: String, width: Int): UInt = Lit(parse(n), width)
-  /** Create a UInt literal with specified width. */
-  def apply(value: BigInt, width: Width): UInt = Lit(value, width)
-  def Lit(value: BigInt, width: Int): UInt = Lit(value, Width(width))
-   /** Create a UInt literal with inferred width. */
-  def Lit(value: BigInt): UInt = Lit(value, Width())
-  def Lit(n: String): UInt = Lit(parse(n), parsedWidth(n))
-   /** Create a UInt literal with fixed width. */
-  def Lit(n: String, width: Int): UInt = Lit(parse(n), width)
+
    /** Create a UInt literal with specified width. */
-  def Lit(value: BigInt, width: Width): UInt = {
+  protected[chisel3] def Lit(value: BigInt, width: Width): UInt = {
     val lit = ULit(value, width)
     val result = new UInt(lit.width, Some(lit))
     // Bind result to being an Literal
     result.binding = LitBinding()
     result
   }
+
   /** Create a UInt with the specified range */
   def apply(range: Range): UInt = {
-    width(range.getWidth)
+    apply(range.getWidth)
   }
   /** Create a UInt with the specified range */
   def apply(range: (NumericBound[Int], NumericBound[Int])): UInt = {
     apply(KnownUIntRange(range._1, range._2))
   }
-
-  /** Create a UInt with a specified width - compatibility with Chisel2. */
-  // NOTE: This resolves UInt(width = 32)
-  def apply(dir: Option[Direction] = None, width: Int): UInt = apply(Width(width))
-  /** Create a UInt literal with inferred width.- compatibility with Chisel2. */
-  def apply(value: BigInt): UInt = apply(value, Width())
-  /** Create a UInt with a specified direction and width - compatibility with Chisel2. */
-  def apply(dir: Direction, width: Int): UInt = apply(dir, Width(width))
-  /** Create a UInt with a specified direction, but unspecified width - compatibility with Chisel2. */
-  def apply(dir: Direction): UInt = apply(dir, Width())
-  def apply(dir: Direction, wWidth: Width): UInt = {
-    val result = apply(wWidth)
-    dir match {
-      case Direction.Input => Input(result)
-      case Direction.Output => Output(result)
-      case Direction.Unspecified => result
-    }
-  }
-
-  private def parse(n: String) = {
-    val (base, num) = n.splitAt(1)
-    val radix = base match {
-      case "x" | "h" => 16
-      case "d" => 10
-      case "o" => 8
-      case "b" => 2
-      case _ => Builder.error(s"Invalid base $base"); 2
-    }
-    BigInt(num.filterNot(_ == '_'), radix)
-  }
-
-  private def parsedWidth(n: String) =
-    if (n(0) == 'b') {
-      Width(n.length-1)
-    } else if (n(0) == 'h') {
-      Width((n.length-1) * 4)
-    } else {
-      Width()
-    }
 }
 
 object UInt extends UIntFactory
+object Bits extends UIntFactory
 
-sealed class SInt private (width: Width, lit: Option[SLit] = None)
+sealed class SInt private[core] (width: Width, lit: Option[SLit] = None)
     extends Bits(width, lit) with Num[SInt] {
 
   private[core] override def cloneTypeWidth(w: Width): this.type =
@@ -622,13 +563,13 @@ sealed class SInt private (width: Width, lit: Option[SLit] = None)
   private[chisel3] def toType = s"SInt$width"
 
   override private[chisel3] def fromInt(value: BigInt, width: Int): this.type =
-    SInt(value, width).asInstanceOf[this.type]
+    value.asSInt(width.W).asInstanceOf[this.type]
 
   final def unary_- (): SInt = macro SourceInfoTransform.noArg
   final def unary_-% (): SInt = macro SourceInfoTransform.noArg
 
-  def unary_- (implicit sourceInfo: SourceInfo): SInt = SInt(0) - this
-  def unary_-% (implicit sourceInfo: SourceInfo): SInt = SInt(0) -% this
+  def unary_- (implicit sourceInfo: SourceInfo): SInt = 0.S - this
+  def unary_-% (implicit sourceInfo: SourceInfo): SInt = 0.S -% this
 
   /** add (default - no growth) operator */
   override def do_+ (that: SInt)(implicit sourceInfo: SourceInfo): SInt =
@@ -696,7 +637,7 @@ sealed class SInt private (width: Width, lit: Option[SLit] = None)
 
   final def abs(): UInt = macro SourceInfoTransform.noArg
 
-  def do_abs(implicit sourceInfo: SourceInfo): UInt = Mux(this < SInt(0), (-this).asUInt, this.asUInt)
+  def do_abs(implicit sourceInfo: SourceInfo): UInt = Mux(this < 0.S, (-this).asUInt, this.asUInt)
 
   override def do_<< (that: Int)(implicit sourceInfo: SourceInfo): SInt =
     binop(sourceInfo, SInt(this.width + that), ShiftLeftOp, that)
@@ -718,65 +659,38 @@ sealed class SInt private (width: Width, lit: Option[SLit] = None)
   }
 }
 
-object SInt {
+trait SIntFactory {
   /** Create an SInt type with inferred width. */
   def apply(): SInt = apply(Width())
   /** Create a SInt type or port with fixed width. */
   def apply(width: Width): SInt = new SInt(width)
-  /** Create a SInt type or port with fixed width. */
-  def width(width: Int): SInt = apply(Width(width))
-  /** Create an SInt type with specified width. */
-  def width(width: Width): SInt = new SInt(width)
-
-  /** Create an SInt literal with inferred width. */
-  def apply(value: BigInt): SInt = Lit(value)
-  /** Create an SInt literal with fixed width. */
-  def apply(value: BigInt, width: Int): SInt = Lit(value, width)
-
-  /** Create an SInt literal with specified width. */
-  def apply(value: BigInt, width: Width): SInt = Lit(value, width)
 
   /** Create a SInt with the specified range */
   def apply(range: Range): SInt = {
-    width(range.getWidth)
+    apply(range.getWidth)
   }
   /** Create a SInt with the specified range */
   def apply(range: (NumericBound[Int], NumericBound[Int])): SInt = {
     apply(KnownSIntRange(range._1, range._2))
   }
 
-  def Lit(value: BigInt): SInt = Lit(value, Width())
-  def Lit(value: BigInt, width: Int): SInt = Lit(value, Width(width))
    /** Create an SInt literal with specified width. */
-  def Lit(value: BigInt, width: Width): SInt = {
-
+  protected[chisel3] def Lit(value: BigInt, width: Width): SInt = {
     val lit = SLit(value, width)
     val result = new SInt(lit.width, Some(lit))
     // Bind result to being an Literal
     result.binding = LitBinding()
     result
   }
-  /** Create a SInt with a specified width - compatibility with Chisel2. */
-  def apply(dir: Option[Direction] = None, width: Int): SInt = apply(Width(width))
-  /** Create a SInt with a specified direction and width - compatibility with Chisel2. */
-  def apply(dir: Direction, width: Int): SInt = apply(dir, Width(width))
-  /** Create a SInt with a specified direction, but unspecified width - compatibility with Chisel2. */
-  def apply(dir: Direction): SInt = apply(dir, Width())
-  def apply(dir: Direction, wWidth: Width): SInt = {
-    val result = apply(wWidth)
-    dir match {
-      case Direction.Input => Input(result)
-      case Direction.Output => Output(result)
-      case Direction.Unspecified => result
-    }
-  }
 }
 
+object SInt extends SIntFactory
+
 // REVIEW TODO: Why does this extend UInt and not Bits? Does defining airth
 // operations on a Bool make sense?
 /** A data type for booleans, defined as a single bit indicating true or false.
   */
-sealed class Bool(lit: Option[ULit] = None) extends UInt(Width(1), lit) {
+sealed class Bool(lit: Option[ULit] = None) extends UInt(1.W, lit) {
   private[core] override def cloneTypeWidth(w: Width): this.type = {
     require(!w.known || w.get == 1)
     new Bool().asInstanceOf[this.type]
@@ -784,7 +698,7 @@ sealed class Bool(lit: Option[ULit] = None) extends UInt(Width(1), lit) {
 
   override private[chisel3] def fromInt(value: BigInt, width: Int): this.type = {
     require((value == 0 || value == 1) && width == 1)
-    Bool(value == 1).asInstanceOf[this.type]
+    (value == 1).asBool.asInstanceOf[this.type]
   }
 
   // REVIEW TODO: Why does this need to exist and have different conventions
@@ -822,31 +736,23 @@ sealed class Bool(lit: Option[ULit] = None) extends UInt(Width(1), lit) {
   def do_asClock(implicit sourceInfo: SourceInfo): Clock = pushOp(DefPrim(sourceInfo, Clock(), AsClockOp, ref))
 }
 
-object Bool {
+trait BoolFactory {
   /** Creates an empty Bool.
    */
   def apply(): Bool = new Bool()
 
   /** Creates Bool literal.
    */
-  def apply(x: Boolean): Bool = Lit(x)
-  def Lit(x: Boolean): Bool = {
+  protected[chisel3] def Lit(x: Boolean): Bool = {
     val result = new Bool(Some(ULit(if (x) 1 else 0, Width(1))))
     // Bind result to being an Literal
     result.binding = LitBinding()
     result
   }
-  /** Create a UInt with a specified direction and width - compatibility with Chisel2. */
-  def apply(dir: Direction): Bool = {
-    val result = apply()
-    dir match {
-      case Direction.Input => Input(result)
-      case Direction.Output => Output(result)
-      case Direction.Unspecified => result
-    }
-  }
 }
 
+object Bool extends BoolFactory
+
 object Mux {
   /** Creates a mux, whose output is one of the inputs depending on the
     * value of the condition.
@@ -856,7 +762,7 @@ object Mux {
     * @param alt the value chosen when `cond` is false
     * @example
     * {{{
-    * val muxOut = Mux(data_in === UInt(3), UInt(3, 4), UInt(0, 4))
+    * val muxOut = Mux(data_in === 3.U, 3.U(4.W), 0.U(4.W))
     * }}}
     */
   def apply[T <: Data](cond: Bool, con: T, alt: T): T = macro MuxTransform.apply[T]
diff --git a/chiselFrontend/src/main/scala/chisel3/core/Mem.scala b/chiselFrontend/src/main/scala/chisel3/core/Mem.scala
index a43b19fe..1863e921 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Mem.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Mem.scala
@@ -40,7 +40,7 @@ sealed abstract class MemBase[T <: Data](t: T, val length: Int) extends HasId wi
     */
   def apply(idx: Int): T = {
     require(idx >= 0 && idx < length)
-    apply(UInt(idx))
+    apply(idx.asUInt)
   }
 
   /** Creates a read/write accessor into the memory with dynamic addressing.
diff --git a/chiselFrontend/src/main/scala/chisel3/core/SeqUtils.scala b/chiselFrontend/src/main/scala/chisel3/core/SeqUtils.scala
index 558dea7a..e435860e 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/SeqUtils.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/SeqUtils.scala
@@ -25,12 +25,12 @@ private[chisel3] object SeqUtils {
     }
   }
 
-  /** Outputs the number of elements that === Bool(true).
+  /** Outputs the number of elements that === true.B.
     */
   def count(in: Seq[Bool]): UInt = macro SourceInfoTransform.inArg
 
   def do_count(in: Seq[Bool])(implicit sourceInfo: SourceInfo): UInt = in.size match {
-    case 0 => UInt(0)
+    case 0 => 0.U
     case 1 => in.head
     case n => count(in take n/2) +& count(in drop n/2)
   }
@@ -57,7 +57,7 @@ private[chisel3] object SeqUtils {
     if (in.tail.isEmpty) {
       in.head._2
     } else {
-      val masked = for ((s, i) <- in) yield Mux(s, i.asUInt, UInt(0))
+      val masked = for ((s, i) <- in) yield Mux(s, i.asUInt, 0.U)
       val width = in.map(_._2.width).reduce(_ max _)
       in.head._2.cloneTypeWidth(width).fromBits(masked.reduceLeft(_|_))
     }
diff --git a/chiselFrontend/src/main/scala/chisel3/core/When.scala b/chiselFrontend/src/main/scala/chisel3/core/When.scala
index 196e7903..7501ebb1 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/When.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/When.scala
@@ -18,9 +18,9 @@ object when {  // scalastyle:ignore object.name
     *
     * @example
     * {{{
-    * when ( myData === UInt(3) ) {
+    * when ( myData === 3.U ) {
     *   // Some logic to run when myData equals 3.
-    * } .elsewhen ( myData === UInt(1) ) {
+    * } .elsewhen ( myData === 1.U ) {
     *   // Some logic to run when myData equals 1.
     * } .otherwise {
     *   // Some logic to run when myData is neither 3 nor 1.
diff --git a/chiselFrontend/src/main/scala/chisel3/core/package.scala b/chiselFrontend/src/main/scala/chisel3/core/package.scala
new file mode 100644
index 00000000..77f35c23
--- /dev/null
+++ b/chiselFrontend/src/main/scala/chisel3/core/package.scala
@@ -0,0 +1,106 @@
+package chisel3 {
+  import internal.Builder
+
+  package object core {
+    import internal.firrtl.Width
+
+    /**
+    * These implicit classes allow one to convert scala.Int|scala.BigInt to
+    * Chisel.UInt|Chisel.SInt by calling .asUInt|.asSInt on them, respectively.
+    * The versions .asUInt(width)|.asSInt(width) are also available to explicitly
+    * mark a width for the new literal.
+    *
+    * Also provides .asBool to scala.Boolean and .asUInt to String
+    *
+    * Note that, for stylistic reasons, one should avoid extracting immediately
+    * after this call using apply, ie. 0.asUInt(1)(0) due to potential for
+    * confusion (the 1 is a bit length and the 0 is a bit extraction position).
+    * Prefer storing the result and then extracting from it.
+    */
+    implicit class fromBigIntToLiteral(val bigint: BigInt) {
+      /** Int to UInt conversion, recommended style for constants.
+        */
+      def U: UInt = UInt.Lit(bigint, Width())  // scalastyle:ignore method.name
+      /** Int to SInt conversion, recommended style for constants.
+        */
+      def S: SInt = SInt.Lit(bigint, Width())  // scalastyle:ignore method.name
+      /** Int to UInt conversion with specified width, recommended style for constants.
+        */
+      def U(width: Width): UInt = UInt.Lit(bigint, width)  // scalastyle:ignore method.name
+      /** Int to SInt conversion with specified width, recommended style for constants.
+        */
+      def S(width: Width): SInt = SInt.Lit(bigint, width)  // scalastyle:ignore method.name
+
+      /** Int to UInt conversion, recommended style for variables.
+        */
+      def asUInt: UInt = UInt.Lit(bigint, Width())
+      /** Int to SInt conversion, recommended style for variables.
+        */
+      def asSInt: SInt = SInt.Lit(bigint, Width())
+      /** Int to UInt conversion with specified width, recommended style for variables.
+        */
+      def asUInt(width: Width): UInt = UInt.Lit(bigint, width)
+      /** Int to SInt conversion with specified width, recommended style for variables.
+        */
+      def asSInt(width: Width): SInt = SInt.Lit(bigint, width)
+    }
+
+    implicit class fromIntToLiteral(val int: Int) extends fromBigIntToLiteral(int)
+    implicit class fromLongToLiteral(val long: Long) extends fromBigIntToLiteral(long)
+
+    implicit class fromStringToLiteral(val str: String) {
+      /** String to UInt parse, recommended style for constants.
+        */
+      def U: UInt = UInt.Lit(parse(str), parsedWidth(str))  // scalastyle:ignore method.name
+      /** String to UInt parse with specified width, recommended style for constants.
+        */
+      def U(width: Width): UInt = UInt.Lit(parse(str), width)  // scalastyle:ignore method.name
+
+      /** String to UInt parse, recommended style for variables.
+        */
+      def asUInt: UInt = UInt.Lit(parse(str), parsedWidth(str))
+      /** String to UInt parse with specified width, recommended style for variables.
+        */
+      def asUInt(width: Width): UInt = UInt.Lit(parse(str), width)
+
+      protected def parse(n: String) = {
+        val (base, num) = n.splitAt(1)
+        val radix = base match {
+          case "x" | "h" => 16
+          case "d" => 10
+          case "o" => 8
+          case "b" => 2
+          case _ => Builder.error(s"Invalid base $base"); 2
+        }
+        BigInt(num.filterNot(_ == '_'), radix)
+      }
+
+      protected def parsedWidth(n: String) =
+        if (n(0) == 'b') {
+          Width(n.length-1)
+        } else if (n(0) == 'h') {
+          Width((n.length-1) * 4)
+        } else {
+          Width()
+        }
+    }
+
+    implicit class fromBooleanToLiteral(val boolean: Boolean) {
+      /** Boolean to Bool conversion, recommended style for constants.
+        */
+      def B: Bool = Bool.Lit(boolean)  // scalastyle:ignore method.name
+
+      /** Boolean to Bool conversion, recommended style for variables.
+        */
+      def asBool: Bool = Bool.Lit(boolean)
+    }
+
+    implicit class fromDoubleToLiteral(val double: Double) {
+      def F(binaryPoint: Int): FixedPoint = FixedPoint.fromDouble(double, binaryPoint = binaryPoint)
+    }
+
+    implicit class fromIntToWidth(val int: Int) {
+      def W: Width = Width(int)  // scalastyle:ignore method.name
+    }
+  }
+}