From: Mauricio Fernandez <mfp@...>
Date: 2006-02-01T17:20:37+09:00
Subject: Re: memoize to a file

On Wed, Feb 01, 2006 at 12:32:57PM +0900, Brian Buckley wrote:
> My questions:
> 1  What is causing this error? (possibly Windows related?)

IIRC File.read(file) doesn't open the file in binary mode; try 
File.open(file, "rb"){|f| f.read}

> 2  What is the purpose of the rescue{} suppressing the error info in the
> first place?

setting cache to {} if Marshal.load fails for some reason (e.g. a major
change in the Marshal format across Ruby versions).

> 3  Instead of using Marshall would using yaml be a reasonable alternative?
> (I am thinking of readability of the cache file and also capability to
> pre-populate it)

I wouldn't do that:
* Marshal is faster than Syck (especially when dumping data)
* YAML takes more space than Marshal'ed data
* there are still more bugs in Syck than in Marshal (the nastiest memory
  issues are believed to be fixed, but there is still occasional data
  corruption)
* Marshal is more stable across Ruby releases

As for editing the cache, you can always do
 File.open("cache.yaml", "w") do |out|
   YAML.dump(Marshal.load(File.open("cache", "rb"){|f| f.read}), out)
 end

-- 
Mauricio Fernandez