# -*- Tcl -*-
package require nx
package require nx::test

# just 8.6 or newer
if {[info command yield] eq ""} return

#
# Test coroutine / yield
#
nx::Test case number-generator {
  nx::Object create ::numbers {
    # set instance variable used in coroutine
    set :delta 2
    :public object method ++ {} {
      yield
      set i 0
      while 1 {
	yield $i
	incr i ${:delta}
      }
    }
  }
  # create coroutine
  coroutine nextNumber ::numbers ++
  set ::j 0
  # use coroutine
  for {set i 0} {$i < 10} {incr i} {
    incr ::j [nextNumber]
  }

  # remove coroutine
  rename nextNumber {}

  ? {set ::j} 90
}

#
# Test coroutine / yield 
#
nx::Test case enumerator1 {

  #
  # enumerator with yield in a single class
  #
  nx::Class create Enumerator {
    :property members:0..n
    :public method yielder {} {
      yield [info coroutine]
      foreach m ${:members} {
	yield $m
      }
      return -level 2 -code break
    }
    :public method next {} {${:coro}}
    :method init {} {
      :require namespace
      set :coro [coroutine [self]::coro [self] yielder]
    }
  }
  
  #
  # Some application class using the enumerator (just used for easy
  # testing)
  #
  nx::Class create Foo {
    :public method sum {} {
      set sum 0
      set e [Enumerator new -members {1 2 3}]
      while 1 {
	incr sum [$e next]
      }
      return $sum
    }
    :create f1
  }
  
  ? {f1 sum} 6
}


nx::Test case enumerator2 {
  
  #
  # Define separate classes for Yielder and Enumerator
  #
  nx::Class create Yielder {
    :property {block ";"}
    :variable continuation ""

    #
    # make apply available as a method
    #
    :public alias apply ::apply

    #
    # The method "yielder" is the working horse for next. We need this
    # since the interface of Tcl's coroutines is based on a separate
    # cmd for continuation in the coroutine. The block can be
    # configured by application classes.
    #
    :public method yielder {} {
      yield [info coroutine]
      eval ${:block}
      return -level 2 -code break
    }

    #
    # The method "next" simply forwards to the continuation
    #
    :public method next {} {${:continuation}}

    #
    # The method "each" is based on the method "next" and applies the
    # value returned by next to the lambda expression
    #
    :public method each {var body} {
      while 1 {
	uplevel [list set $var [:next]]
	uplevel $body
      }
    }

    #
    # When a yielder is generated, we create automatically a coroutine
    # for it. The coroutine is placed under the current object, this
    # ensures simple cleanup (but is most probably not the fastest
    # variant, since we have to require a namespace).
    #
    :method init {} {
      :require namespace
      set :continuation [coroutine [self]::coro [self] yielder]
    }
  }

  #
  # The class "Enumerator" provides some application logic for the
  # class "Yielder". We use here a list of elements as base
  # representation.
  #
  nx::Class create Enumerator -superclass Yielder {
    :property members:0..n
    :property {block {
      foreach m ${:members} { yield $m }
    }}
  }

  #
  # Some application class using the enumerator (just used for easy
  # testing)
  #
  nx::Class create Foo {

    # test Enumerator.next
    :public method sum {} {
      set sum 0
      set e [Enumerator new -members {1 2 3}]
      while 1 { incr sum [$e next] }
      return $sum
    }
    
    :public method set {var} {
      set :$var
    }

    # test Enumerator.each
    :public method concat {} {
      set string "-"
      set i 0
      set e [Enumerator new -members {a be bu}]
      $e each x { append string $x-([incr i])- }
      return $string
    }
    
    :create f1
  }
  
  ? {f1 sum} 6
  ? {f1 concat} "-a-(1)-be-(2)-bu-(3)-"


  #
  # Define a class ATeam that uses "Enumerator", refines the method
  # "each" and adds another method "concat"
  #
  nx::Class create ATeam -superclass Enumerator {
    #
    # Overload "each" to show overloading. Here, we simply capitalize
    # the memebers in the "each" method.
    #
    :public method each {var body} {
      while 1 {
	set value [string totitle [:next]]
	uplevel [list set $var $value]
	uplevel $body
      }
    }
    # Define some arbitrary method using ATeam.each
    :public method concat {} {
      set string "-"
      :each x { append string $x- }
      return $string
    }
  }
  ATeam create a1 -members {alice bob ceasar}
  ? {a1 concat } "-Alice-Bob-Ceasar-"
}

#
# apply
#
nx::Test case apply {

  # Register apply as an alias
  ::nx::Object public alias apply ::apply

  ::nx::Object create o {
    # Set an object variable
    set :delta 100

    # Define a standard map function based on apply
    :public object method map {lambda values} {
      set result {}
      foreach value $values {
	lappend result [:apply $lambda $value]
      }
      return $result
    }

    :object method foo {x} {return $x-$x}
  }

  # Two examples from the apply man page
  ? {o map {x {return [string length $x]:$x}} {a bb ccc dddd}} \
      "1:a 2:bb 3:ccc 4:dddd"
  ? {o map {x {expr {$x**2 + 3*$x - 2}}} {-4 -3 -2 -1 0 1 2 3 4}} \
      "2 -2 -4 -4 -2 2 8 16 26"

  ## Test case accessing object specific variable
  #? {o map {x {::nsf::__db_show_stack; return [expr {$x * ${:delta}}]}} {-4 -3 -2 -1 0 1 2 3 4}} \
  #    "-400 -300 -200 -100 0 100 200 300 400"

  # Test case accessing object specific variable
  ? {o map {x {expr {$x * ${:delta}}}} {-4 -3 -2 -1 0 1 2 3 4}} \
      "-400 -300 -200 -100 0 100 200 300 400"

  # Test case calling own method via apply
  ? {o map {x {:foo $x}} {hello world}} \
      "hello-hello world-world"
}