How to do it…

Let's compress and decompress data by executing the following steps:

The code is as follows:

void main() {
  import std.zlib, std.file;
  auto compressor = new Compress(HeaderFormat.gzip);
  void[] compressedData;
  compressedData ~= compressor.compress("Hello, ");
  compressedData ~= compressor.compress("world!");
  compressedData ~= compressor.flush();
  std.file.write("compressed.gz", compressedData);
}

Running the program will create a file, compressed.gz, which can be unzipped to become a text file with Hello, world!.

How it works…

The std.zlib module doesn't follow exactly the same pattern as std.digest (the implementation of std.zlib was written before ranges were incorporated into Phobos), but it is a very simple API. It works with one block of data at a time, returning the compressed or uncompressed block. When finished, the flush method clears any partial blocks, returning the final piece of data.

There are also convenience functions, compress and uncompress, that can perform the operation in a single function call if you have all the data available as a single array at once.