Ronald Fischer wrote:

> Is there a principal reason when to prefer call over yield (or vice 
> versa), or are these only syntactic variations of the same feature?

I am learning to consider 'yield' as a fossil of an early Ruby that could 
not treat the bound block as a variable. I only use 'yield' as a slight 
convenience - a few less characters to type - in application-specific code.

When writing API-style code, I always start with &block because it's only a 
matter of time before I refactor the code and start passing that &block into 
a helper method.

-- 
  Phlip
  http://www.oreilly.com/catalog/9780596510657/
  "Test Driven Ajax (on Rails)"
  assert_xpath, assert_javascript, & assert_ajax