From: Ezra Zygmuntowicz <ezmobius@...>
Date: 2006-06-10T06:36:55+09:00
Subject: Re: ... building my own end-fix statements.


On Jun 9, 2006, at 1:44 PM, Jeff Wood wrote:

> I believe it's possible to define my own end-fix qualifiers like "if"
> and "unless" ...
>
> Can anybody provide code examples for defining such a construct in  
> Ruby?
>
> For instance :
>
> x.doSomething() when x.ready?
>
> which would call x.ready? repeatedly until it returned a true then
> would call x.doSomething()
>
> ... I know I could do
>
> while( not x.ready? )
> sleep 0.5
> wend
>
> x.doSomething()
>
> but I'd rather not.
>
> even a
>
> when( x.ready? ) { |result| x.doSomething() } would be fine I guess
> ... but wouldn't work because x.ready? would be precalculated before
> when gets to it... so it wouldn't ever change... I basically need to
> be able to pass two blocks if I were to do this ...
>
> when( isReadyProc, bodyProc ) ... or something like that.
>
> Any ideas ???
>
> --jw.


Hey Jeff-

	You can use until for this. Here is a contrived example:

irb(main):001:0> class X
irb(main):002:1>   def initialize
irb(main):003:2>     @foo = 0
irb(main):004:2>   end
irb(main):005:1>   attr_reader :foo
irb(main):006:1>   def increment
irb(main):007:2>     @foo += 1
irb(main):008:2>   end
irb(main):009:1>
irb(main):010:1*   def ready?
irb(main):011:2>     @foo == 50
irb(main):012:2>   end
irb(main):013:1> end
=> nil
irb(main):014:0>
irb(main):015:0* x = X.new
=> #<X:0x337c6c @foo=0>
irb(main):016:0> x.increment until x.ready?
=> nil
irb(main):017:0> puts x.foo
50


Cheers-
-Ezra