chap4.txt

  
  4 ToDo-list
  
  
  4.1 Blueprints
  
  4.1-1 ToDoListEntryToMaintainEqualAttributes
  
  ToDoListEntryToMaintainEqualAttributes( indicator, objects, attributes )  operation
  Returns:  a todo list entry
  
  The  first  argument  is  the  indicator.  It  is  a list of sources like in
  ToDoListEntry.  Each  entry SP has to be a threetuple. First entry of SP has
  to  an object, for which the second entry of SP, which has to be the name of
  an  attribute, must become known. Once the attribute is known to the object,
  it  will  be  compared  to the third entry of the list. This can be a value,
  which  is  compared  directly  a  function, which is launched and its return
  value is compared, or a list, consisting of a function and arguments, so the
  return  value  of the function with given arguments is compared. If there is
  no  third  entry in SP, it is only looked up if the value is known. Once all
  entries  in  indicator are processed like this, and all returned true in the
  comparasion,  a  list  of ToDoListEntryForEqualAttributes is installed. They
  are  installed  for  the two entries of the list objects which can either be
  the  objects  itself  or  a  list containing a function and arguments, which
  return  value  is  used.  For  each  entry  in  attributes  such an entry is
  installed. Such an entry can be the name of an attribute, if both objects in
  objects  should  share the value between attributes with the same name, or a
  list of two names, if the attributes do not have the same name.
  
  4.1-2 ToDoListEntryToMaintainFollowingAttributes
  
  ToDoListEntryToMaintainFollowingAttributes( indicator, objects, attributes )  operation
  Returns:  a todo list entry
  
  This   function   creates   a   ToDoListEntry   which  can  install  several
  ToDoListEntries.  The first two arguments, indicator and objects except that
  there  will  be  only  ToDoListEntries  installed between the two objects in
  objects.  Each  entry  in attributes can either be a string which means that
  the  attribute  with the given name will be set from the first to the second
  object  in objects once it is known. The third argument attributes is a list
  of  attributes that will be propagated by ToDoListEntries. Each entry TP can
  either  be a list consisting of a DescriptionOfImplication string and one of
  the  following or just one of the following lists: It can be a string, which
  means  that  the  Attribute  with the given name will be propagated from the
  first  to  the  second  object. It can be a list, consisting of two entries,
  where  the  first  entry  is a list of sources like in ToDoListEntry and the
  second  might  be  a  function which will be launched once the first part is
  fulfilled.  It can also be a threetuple which will serve as second to fourth
  argument  of  ToDoListEntry.  Or  it  can  be  a  string, which will set the
  attribute named like this of the first object to the one named in the second
  object
  
  4.1-3 ToDoListEntry
  
  ToDoListEntry( source, target_list )  operation
  Returns:  a todo list entry
  
  This  function  allows  to create more than one ToDoListEntry with identical
  list of sources at one time. First argument is a list of sources like in the
  other  ToDoListEntry  functions  Second  argument  is a list of threetuples,
  which  serve  as  second  to fourth argument of ToDoListEntry or a function,
  which  serves  as  second  argument  for  ToDoListEntry  or  a  tuple with a
  description string and one of the above.
  
  4.1-4 ToDoList_this_object
  
  ToDoList_this_object global variable
  
  Represents the objects for which the blueprint is created in the arguments
  
  4.1-5 ToDoListEntryToMaintainEqualAttributesBlueprint
  
  ToDoListEntryToMaintainEqualAttributesBlueprint( filter, indicator, objects, attributes )  operation
  Returns:  nothing
  
  This   function   installs   an   immediate   method   which   can   install
  ToDoListEntryToMaintainEqualAttributes. First argument must be a filter, and
  once  the  filter becomes true the ToDoListEntryToMaintainEqualAttributes is
  installed  with  the  second  to fourth argument as first to third. In those
  attributes,  at  any  point,  the variable ToDoList_this_object can be used.
  When  the  entry is installed This will be replaced with the object to which
  the filters became known, i.e. the one which triggered the immediate method.
  
  4.1-6 ToDoListEntryToMaintainFollowingAttributesBlueprint
  
  ToDoListEntryToMaintainFollowingAttributesBlueprint( arg1, arg2, arg3, arg4 )  operation
  Returns:  nothing
  
  The     same    as    ToDoListEntryToMaintainEqualAttributesBlueprint    for
  ToDoListEntryToMaintainFollowingAttributes
  
  4.1-7 ToDoListEntryBlueprint
  
  ToDoListEntryBlueprint( arg1, arg2, arg3 )  operation
  Returns:  nothing
  
  The     same    as    ToDoListEntryToMaintainEqualAttributesBlueprint    for
  ToDoListEntry
  
  
  4.2 ToDo-list entries
  
  4.2-1 AddToToDoList
  
  AddToToDoList( E )  operation
  
  Adds  the  ToDo-list  entry  E  to the ToDo-lists of it's source objects and
  creates  a  new  one,  if this is needed. This function might be called with
  lists of entries
  
  4.2-2 SourcePart
  
  SourcePart( entry )  operation
  Returns:  a list
  
  Returns  the  a list of source parts of the ToDo-list entry entry. This is a
  triple  of an object, a name of a filter/attribute, and a value to which the
  attribute has to be set to activate the entry
  
  4.2-3 TargetPart
  
  TargetPart( entry )  operation
  Returns:  a list
  
  Returns the target part of the ToDo-list entry entry. This is a triple of an
  object,  a  name  of  a  filter/attribute, and a value to which the specific
  filter/attribute  should be set. The third entry of the list might also be a
  function to which return value the attribute is set.
  
  4.2-4 ProcessAToDoListEntry
  
  ProcessAToDoListEntry( arg )  operation
  Returns:  a boolean
  
  Processes  a  ToDo-list entry, i.e. sets the information given in TargetPart
  if  the  definitions  in SourcePart are fulfilled. Returns a function if the
  entry could be processed, false if not, and fail if SourcePart or TargetPart
  weren't availible anymore.
  
  4.2-5 ToDoListEntry
  
  ToDoListEntry( arg1, arg2, arg3, arg4 )  operation
  Returns:  a ToDoListEntry
  
  The  first  argument  must be a list consisting of two, three or four-tuples
  where  the  first entry must be the object to which the attribute given as a
  string  in  the second entry must be known to process this entry. The second
  entry  can  also be a list of strings, in that case all the attributes given
  as  names  must be known. Also, in this case, only two entries in this tuple
  are  allowed.  The  third  part  can  be  a value or a list, consisting of a
  function  followed  by  arguments  which  will  be  computed by the time the
  attribute  given  as  second  entry becomes known to the first entry. If the
  second  part  is  only a string, and there is a third entry in the tuple the
  attribute is compared to the third entry. One can set a comparating function
  as  fourth  entry,  which must take two entries and return false or true. If
  the  value  of the attribute matches the (computed) value in the third entry
  for  all  members  of  the list in the first argument the attribute given as
  third  argument, also by name, of the second argument is set to the value of
  the  fourth argument. This can also be a list which has to be computed, or a
  function, which retun value is used in this case.
  
  4.2-6 ToDoListEntry
  
  ToDoListEntry( arg1, arg2 )  operation
  Returns:  a ToDoListEntry
  
  The  first  argument  is  a  list  of  three-tubles  like  above.  Once  all
  preconditions  become  fulfilled  the  function  given as second argument is
  launched.
  
  4.2-7 SetTargetValueObject
  
  SetTargetValueObject( entry, value )  operation
  Returns:  nothing
  
  If the given value of the target part is the return value of a function this
  command  sets  the  target value of the entry to a function. This is done to
  keep proof tracking availible.
  
  4.2-8 SetTargetObject
  
  SetTargetObject( entry, obj )  operation
  Returns:  nothing
  
  If  the target object, i.e. the first entry of the target part, was given as
  a  function,  this method can set this entry to the return value computed in
  ProcessToDoListEntry. This happens atomatically, do not worry about it.
  
  4.2-9 ToDoListEntryWithContraposition
  
  ToDoListEntryWithContraposition( sobj, source_prop, sval, tobj, target, tval )  operation
  Returns:  a ToDoListEntry
  
  Creates  a ToDoListEntry which also installs a contraposition. The arguments
  source_prop  and  target  need to be strings which name a property, and sval
  and tval need to be boolean values, i.e. true or false.
  
  4.2-10 DescriptionOfImplication
  
  DescriptionOfImplication( arg )  attribute
  Returns:  a list
  
  Has to be set to a string, which describes the reason for the conclusion. If
  the  ToDo-list entry is displayed, the given string will be displayed with a
  because before it.
  
  4.2-11 ToDoListEntryForEqualAttributes
  
  ToDoListEntryForEqualAttributes( arg1, arg2, arg3, arg4 )  operation
  Returns:  a ToDoListEntry
  
  Creates  a  ToDoListEntry  for  two  equal attributes, which means that both
  values of the two attributes will be propagated in both directions.
  
  4.2-12 ToDoListEntryForEquivalentAttributes
  
  ToDoListEntryForEquivalentAttributes( arg1, arg2, arg3, arg4, arg5, arg6 )  operation
  Returns:  a ToDoListEntry
  
  Creates a ToDoListEntry for two equivalent attributes, which means that both
  values  of  the two attributes will be propagated in both directions. Please
  note that this one does NOT implement contrapositions.
  
  
  4.3 Category
  
  4.3-1 IsToDoList
  
  IsToDoList( arg )  filter
  Returns:  true or false
  
  This  is  the  category  of ToDo-lists. Every ToDo-list is an object of this
  category, which basically contains the ToDo-lists.
  
  
  4.4 Constructor
  
  4.4-1 NewToDoList
  
  NewToDoList(  )  operation
  Returns:  nothing
  
  Creates a new empty ToDo-list.
  
  
  4.5 This is the magic
  
  4.5-1 Process_A_ToDo_List_Entry
  
  Process_A_ToDo_List_Entry( arg )  function
  Returns:  a boolean
  
  Gets  a  ToDo-list  entry,  which  is a pair of a list of strings and a weak
  pointer  object,  and processes it. If the action was done, it returns true,
  if  not, it returns false, and it returns fail if the action is not possible
  anymore due to deleted objects.
  
  4.5-2 ProcessToDoList
  
  ProcessToDoList( A )  attribute
  Returns:  nothing
  
  This  is the magic! This attribute is never set. Creating an ToDo-list entry
  installs  an ImmediateMethod for this attribute for the specific category of
  the  object  to which ToDo-list is added, and the filter the entry contains.
  It  is  then  triggert if the filters become applicable, so the ToDo-list is
  processed
  
  
  4.6 Methods for all objects
  
  4.6-1 ToDoList
  
  ToDoList( arg )  attribute
  Returns:  A ToDo-list
  
  Returns the ToDo-list of an object, or creates a new one.
  
  
  4.7 Proof tracking
  
  This  is  a  way to track proofs from ToDoLists. Not only for debugging, but
  also for knowing how things work together.
  
  4.7-1 TraceProof
  
  TraceProof( obj, name, val )  operation
  Returns:  a tree
  
  If  the  object  obj  has  the attribute name, and its value is val, and the
  knowledge  has been obtained trough ToDoList-entries, this method traces the
  way the property was set, and returns a tree which describes the full way of
  how the attribute became known.
  
  
  4.8 Maintainance
  
  4.8-1 ActivateToDoList
  
  ActivateToDoList( arg )  operation
  Returns:  nothing
  
  This operation activates ToDoLists for the argument.
  
  4.8-2 ActivateToDoList
  
  ActivateToDoList(  )  operation
  Returns:  nothing
  
  This operation activates ToDoLists for all objects.
  
  4.8-3 DeactivateToDoList
  
  DeactivateToDoList( arg )  operation
  Returns:  nothing
  
  This operation deactivates ToDoLists for the argument.
  
  4.8-4 DeactivateToDoList
  
  DeactivateToDoList(  )  operation
  Returns:  nothing
  
  This  operation  deactivates  ToDoLists for all objects. Note that it is not
  possible  to  activate  ToDoList  for  a  single  object  while they are not
  activated.  ToDoListEntries will yet be stored for all objects that can have
  ToDoLists.  All  objects  created  while  ToDoLists  are deactivated have by
  default no ToDoList.
  
  4.8-5 ActivateWhereInfosInEntries
  
  ActivateWhereInfosInEntries( arg )  function
  Returns:  nothing
  
  Stores  the  result  of  Where( 100 ) in an entry if the entry is triggered.
  This is not activated by default, since it might slow down the system.
  
  4.8-6 DeactivateWhereInfosInEntries
  
  DeactivateWhereInfosInEntries( arg )  function
  Returns:  nothing
  
  Deactives  the  storage  of  the  result  of  Where(  100  )  if an entry is
  triggered. This is the default.