Concurrency: hypothetical variables and atomic blocks

How does an atomic block differ from one in which all variables are
implicitly hypotheticalized?  I'm thinking that a "retry" exit
statement may be redundant; instead, why not just go with the existing
mechanisms for successful vs. failed block termination, with the minor
modification that when an atomic block fails, the state rolls back?

Also, what can "retry_with" do that testing the atomic block for
failure can't?

-- 
Jonathan "Dataweaver" Lang

• Concurrency: hypothetical variables and atomic blocks by Jonathan Lang
• Re: Concurrency: hypothetical variables and atomic blocks by Sam Vilain
• Re: Concurrency: hypothetical variables and atomic blocks by Darren Duncan
• Re: Concurrency: hypothetical variables and atomic blocks by Ruud H.G. van Tol
• Re: Concurrency: hypothetical variables and atomic blocks by Daniel Hulme
• Re: Concurrency: hypothetical variables and atomic blocks by Sam Vilain
• Re: Concurrency: hypothetical variables and atomic blocks by Larry Wall
• Re: Concurrency: hypothetical variables and atomic blocks by Darren Duncan
• Re: Concurrency: hypothetical variables and atomic blocks by Jonathan Lang
• Re: Concurrency: hypothetical variables and atomic blocks by Jonathan Scott Duff
• Re: Concurrency: hypothetical variables and atomic blocks by Jonathan Worthington