View source for Chain.initiate

== Calling Pattern ==
Call
 local c = sl.chain(a,b[,...])
 -- later
 local i,j = chain.initiate([d[,...]])
Args
 d1..dN optional are variadic arguments of any type
Results
 i is a number
 j is a number

== Example Usage ==

 local b01 = function(n,...)
  print(n)
  return true
 end
 local b02 = function(a,b,c)
  print(a..' '..b..' '..c)
  return string.char(string.byte(a)+1), string.char(string.byte(b)+1), string.char(string.byte(c)+1)
 end
 local b05 = {b02,b02,b02}
 local b00 = sl.chain(b01,b05)
 local b03, b04 = b00.init('a','b','c')
 print(b03)
 print(b04)
 b00.dispose()

 --> a b c
     1
     b c d
     2
     c d e
     3
     3

== Description ==

Calling initiate begins the execution of a previously defined chain object.  Each function in the chain body (b1..bN) is called with a set of variadic arguments in turn.  The first set of arguments are the arguments supplied to the initiate call.  The next set of arguments is the output of the first body function, and so on.  The body index and output of each function is fed to the monitoring function, a, and if a returns true, the next function in the body is called and so on, until the end of the chain is reached.  Initiate returns a [[tuple]] of the number of body functions executed and the total number of body functions. 

== Upon Error ==

Errors occurring in any of the chained functions are reported and handled according to the operant error redirection mode.

== See Also ==

* [http://www.easyuo.com/openeuo/wiki/index.php/Simplelib simplelib]

* [[case]]
* [[chain]]
* [[chain.dispose]]
* [[iterator]]
* [[machine]]
* [[spin]]