Add Generators For Hex Char And String Values

typelevel · May 8, 2019 · 55d504c · 55d504c
1 parent ec5ed7a
commit 55d504c
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Showing 2 changed files with 34 additions and 2 deletions.
diff --git a/jvm/src/test/scala/org/scalacheck/GenSpecification.scala b/jvm/src/test/scala/org/scalacheck/GenSpecification.scala
@@ -270,6 +270,11 @@ object GenSpecification extends Properties("Gen") with GenSpecificationVersionSp
       charType == Character.MODIFIER_SYMBOL || charType == Character.OTHER_SYMBOL
   }
 
+  property("hexChar") = forAll(hexChar){ ch =>
+    val l: Long = java.lang.Long.parseLong(ch.toString, 16)
+    l < 16 && l >= 0
+  }
+
   property("identifier") = forAll(identifier) { s =>
     s.length > 0 && s(0).isLetter && s(0).isLower &&
     s.forall(_.isLetterOrDigit)
@@ -312,6 +317,18 @@ object GenSpecification extends Properties("Gen") with GenSpecificationVersionSp
     }
   }
 
+  property("hexStr") = forAll(hexStr) { s =>
+    if (s.size > 0) {
+      Try(BigInt(new java.math.BigInteger(s, 16))) match {
+        case Success(bi) => bi >= BigInt(0L)
+        case _ => false
+      }
+    }
+    else {
+      true
+    }
+  }
+
   // BigDecimal generation is tricky; just ensure that the generator gives
   // its constructor valid values.
   property("BigDecimal") = forAll { _: BigDecimal => true }

diff --git a/src/main/scala/org/scalacheck/Gen.scala b/src/main/scala/org/scalacheck/Gen.scala
@@ -694,7 +694,7 @@ object Gen extends GenArities with GenVersionSpecific {
     choose(1, gs.length+2).flatMap(pick(_, g1, g2, gs: _*))
 
   /** A generator that randomly picks a given number of elements from a list
-   * 
+   *
    * The elements are not guaranteed to be permuted in random order.
    */
   def pick[T](n: Int, l: Iterable[T]): Gen[collection.Seq[T]] = {
@@ -722,7 +722,7 @@ object Gen extends GenArities with GenVersionSpecific {
   }
 
   /** A generator that randomly picks a given number of elements from a list
-   * 
+   *
    * The elements are not guaranteed to be permuted in random order.
    */
   def pick[T](n: Int, g1: Gen[T], g2: Gen[T], gn: Gen[T]*): Gen[Seq[T]] = {
@@ -766,6 +766,15 @@ object Gen extends GenArities with GenVersionSpecific {
   /** Generates a ASCII printable character */
   def asciiPrintableChar: Gen[Char] = choose(32.toChar, 126.toChar)
 
+  /** Generates a character that can represent a valid hexadecimal digit. This
+    * includes both upper and lower case values.
+    */
+  def hexChar: Gen[Char] = Gen.oneOf(
+    Gen.choose(48.toChar, 57.toChar),  // 0-9
+    Gen.choose(97.toChar, 102.toChar), // a-f
+    Gen.choose(65.toChar, 70.toChar)   // A-F
+  )
+
   //// String Generators ////
 
   /** Generates a string that starts with a lower-case alpha character,
@@ -803,6 +812,12 @@ object Gen extends GenArities with GenVersionSpecific {
   def asciiPrintableStr: Gen[String] =
     listOf(asciiPrintableChar).map(_.mkString)
 
+  /** Generates a string that can represent a valid hexadecimal digit. This
+    * includes both upper and lower case values.
+    */
+  def hexStr: Gen[String] =
+    listOf(hexChar).map(_.mkString)
+
 
   //// Number Generators ////