Merge pull request #133 from lJoublanc/series/1.10.x

Pad-left on pbcd codec (take 2). Fixes #126.
scodec · Jan 21, 2019 · f247b4c · f247b4c
2 parents 6ddb595 + 9469a46
commit f247b4c
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diff --git a/shared/src/main/scala/scodec/codecs/package.scala b/shared/src/main/scala/scodec/codecs/package.scala
@@ -467,7 +467,15 @@ package object codecs {
    * @param nibbles number of nibbles (4-bit chunks)
    * @group numbers
    */
-  def pbcd(nibbles: Int): Codec[Long] = fixedSizeBits(nibbles.toLong*4, vpbcd)
+  def pbcd(nibbles: Int): Codec[Long] = new Codec[Long] {
+    private def width: Long = nibbles.toLong * 4L
+    def decode(bits: BitVector): Attempt[DecodeResult[Long]] = 
+      bits.consumeThen(width)(e => Attempt failure Err(e),
+       (bits,rem) => vpbcd decodeValue bits map (a => DecodeResult(a,rem))
+      )
+    def encode(l : Long): Attempt[BitVector] = vpbcd encode l map (_ padLeft width)
+    def sizeBound = SizeBound exact width
+  }
 
   /**
    * Codec for n-nibble packed decimal (BCD) integers that are represented with `Long`.

diff --git a/unitTests/src/test/scala/scodec/codecs/PackedDecimalCodecTest.scala b/unitTests/src/test/scala/scodec/codecs/PackedDecimalCodecTest.scala
@@ -18,6 +18,12 @@ class PackedDecimalCodecTest extends CodecSuite {
       pbcd(6).decode(hex"010323".bits) should be (Attempt.successful(DecodeResult(10323L, BitVector.empty)))
     }
 
+    "pad left when encoding (#126)" in {
+      pbcd(3).encode(0) shouldEqual Attempt.successful(bin"0000 0000 0000")
+      pbcd(3).encode(1) shouldEqual Attempt.successful(bin"0000 0000 0001")
+      pbcd(3).encode(79) shouldEqual Attempt.successful(bin"0000 0111 1001")
+      pbcd(3).encode(999) shouldEqual Attempt.successful(bin"1001 1001 1001")
+    }
   }
 
   "the lpbcd codec" should {