1. The "reverse-complement" problem here is simply about reading a file, reversing strings and mapping a small set of characters to another one and printing the result. This is really a simple problem and there aren't a lot of optimisations to be done. Really this about having the fastest I/O library and thus doesn't seem like a good way to compare C and Haskell. If you look at the various solutions presented on benchmark games, the core algorithms are all the same and they only differ on how to read/write and the use of threads.
2. The author talks about the importance of reducing cache misses due to pointer indirection and then proceeds by implementing a character buffer as a linked list of small buffers...
3. The C version reads and writes character one by one, this can be greatly improved by reading/writing bigger chunks at once. Actually, the author points out this optimisation but says "that would require significant changes to the code;". So the author spent time optimising the Haskell version, but spending time optimising the C version is too much work? And then arrives at the conclusion Haskell is faster?
4. Commenters on the author's blog cannot reproduce the results...
2. The author talks about the importance of reducing cache misses due to pointer indirection and then proceeds by implementing a character buffer as a linked list of small buffers...
3. The C version reads and writes character one by one, this can be greatly improved by reading/writing bigger chunks at once. Actually, the author points out this optimisation but says "that would require significant changes to the code;". So the author spent time optimising the Haskell version, but spending time optimising the C version is too much work? And then arrives at the conclusion Haskell is faster?
4. Commenters on the author's blog cannot reproduce the results...