<!--
  - Authors:
  -   Christian Schulte <schulte@ps.uni-sb.de>
  -
  - Copyright:
  -   Christian Schulte, 1998
  -
  - Last change:
  -   $Date$ by $Author$
  -   $Revision$
  -
  - This file is part of Mozart, an implementation
  - of Oz 3
  -    http://www.mozart-oz.org
  -
  - See the file "LICENSE" or
  -    http://www.mozart-oz.org/LICENSE.html
  - for information on usage and redistribution
  - of this file, and for a DISCLAIMER OF ALL
  - WARRANTIES.
  -
  -->

<Appendix id="chapter.code">
  <Title/Data and Code Fragments/

  <p>
    This appendix contains code fragments left out in the text's
    chapters.
      
  <section id="section.code.development">
    <title/Application Development/

    <p>
<chunk><title/Body for DB.oz/ 
define
   Data = {Dictionary.new}
   Ctr  = {New class $
                  prop locking
                  attr i:0
                  meth init(I <= 0)
                     lock i := I end
                  end
                  meth get($)
                     lock @i end
                  end
                  meth inc($)
                     lock I=@i+1 in i := I I end
                  end
               end init()}
   
   proc {Add X}
      I={Ctr inc($)}
   in
      {Dictionary.put Data I X}
   end
      
   fun {Get ID}
      {Dictionary.get Data ID}
   end

   fun {GetAll}
      {Map {Dictionary.keys Data}
       fun {$ K}
          {AdjoinAt {Dictionary.get Data K} key K}
       end}
   end
   
   proc {Remove ID}
      {Dictionary.remove Data ID}
   end
</chunk>

<chunk><title/Implementation of Book/
T ={New Tk.toplevel tkInit}
F1={New Tk.frame    tkInit(parent:T relief:sunken bd:2)}
V ={New Tk.variable tkInit(Fs.1.key)}
{Tk.batch 
 grid(b({Map ['' 'From' 'To' 'Price']
         fun {$ A}
            {New Tk.label tkInit(parent:F1 text:A
                                 relief:raised bd:1)}
         end})
      padx:1 pady:1 sticky:ew) |
 {Map Fs
  fun {$ F}
     grid({New Tk.radiobutton tkInit(parent:F1 var:V
                                     value:F.key)}
          b({Map ['from' to price]
             fun {$ A}
                {New Tk.label tkInit(parent:F1 text:F.A)}
             end}))
  end}}
F2={New Tk.frame tkInit(parent:T)}
[FN LN EM] =
{Map ['First name' 'Last name' 'E-Mail']
 fun {$ S}
    E={New Tk.entry tkInit(parent:F2 width:20 bg:wheat)}
 in
    {Tk.send grid({New Tk.label
		   tkInit(parent:F2 text:S#':' anchor:w)}
		  E
		  sticky:ew)}
    fun {$}
       {E tkReturnAtom(get $)}
    end
 end}
B={New Tk.button
   tkInit(parent:T text:'Okay'
	  action: proc {$}
		     Get=form(first: {FN}
			      last:  {LN}
			      email: {EM}
			      key:   {V tkReturnInt($)})
		     {T tkClose}
		  end)}
in
{Tk.send pack(F1 F2 B padx:1#m pady:2#m)}
</chunk>

<chunk><title/Sample flights/
[f('from':'Paris'       to:'Stockholm'   price:234)
 f('from':'Saarbrücken' to:'Paris'       price:345)
 f('from':'New York'    to:'Saarbrücken' price:567)
 f('from':'New York'    to:'Bruxelles'   price:363)
 f('from':'Paris'       to:'Saarbrücken' price:834)
 f('from':'Stockholm'   to:'Bruxelles'   price:333)
 f('from':'London'      to:'Saarbrücken' price:523)
 f('from':'Saarbrücken' to:'London'      price:457)
 f('from':'Bruxelles'   to:'New York'    price:324)
 f('from':'Boston'      to:'Stockholm'   price:765)
 f('from':'Stockholm'   to:'New York'    price:344)
 f('from':'Sydney'      to:'Saarbrücken' price:3452)
 f('from':'Sydney'      to:'Stockholm'   price:2568)]
</chunk>
                              


