add huffman decoder

1 files changed, 43 insertions, 0 deletions

diff --git a/tests/thuffmandecoder.nim b/tests/thuffmandecoder.nim
new file mode 100644
index 0000000..d4d81b4
--- /dev/null
+++ b/tests/thuffmandecoder.nim
@@ -0,0 +1,43 @@
+# gzip-like LZSS compressor
+# Copyright (C) 2018  Pacien TRAN-GIRARD
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+import unittest, streams
+import bitreader, bitwriter
+import huffmantree, huffmandecoder
+
+suite "huffdecoder":
+  let tree = huffmanBranch(
+    huffmanLeaf(1'u),
+    huffmanBranch(
+      huffmanLeaf(2'u),
+      huffmanLeaf(3'u)))
+
+  test "decode":
+    let stream = newStringStream()
+    defer: stream.close()
+    let bitWriter = stream.bitWriter()
+    bitWriter.writeBool(true)  # 2
+    bitWriter.writeBool(false)
+    bitWriter.writeBool(false) # 1
+    bitWriter.writeBool(true)  # 3
+    bitWriter.writeBool(true)
+    bitWriter.flush()
+    stream.setPosition(0)
+    let bitReader = stream.bitReader()
+    let decoder = tree.decoder()
+    check decoder.decode(bitReader) == 2'u
+    check decoder.decode(bitReader) == 1'u
+    check decoder.decode(bitReader) == 3'u