// expand an ambiguous direction throughout a rule
// error if more than one in pattern
IList <AtomicRule> ExpandDirectionMulti(AtomicRule oldrule, Direction olddir)
{
var pcells = oldrule.Patterns.SelectMany(p => p.Cells
.SelectMany(c => c.Where(a => a.Direction == olddir)));
if (pcells.Count() != 1)
{
_parser.CompileError("'{0}' in action cannot be matched", olddir);
}
// expand one rule per single direction
var newrules = new List <AtomicRule>();
foreach (var newdir in _expanddirlookup[olddir])
{
var newrule = oldrule.Clone();
for (var riter = new RuleIterator {
Rule = oldrule
}; !riter.Done; riter.Step())
{
newrule.Patterns[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceDirection(riter.PatternAtoms, olddir, newdir);
newrule.Actions[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceDirection(riter.ActionAtoms, olddir, newdir);
}
newrules.AddRange(ExpandRule(newrule));
}
return(newrules);
}
// expand an OR symbol throughout a rule
// error if more than one in pattern
IList <AtomicRule> ExpandSymbolMulti(AtomicRule oldrule, ObjectSymbol oldsym)
{
var pcells = oldrule.Patterns.SelectMany(p => p.Cells
.SelectMany(c => c.Where(a => a.Symbol == oldsym && !a.IsNegated)));
if (pcells.Count() != 1)
{
return(null);
}
// expand one rule per object id
var newrules = new List <AtomicRule>();
foreach (var newobj in oldsym.ObjectIds)
{
var newrule = oldrule.Clone();
for (var riter = new RuleIterator {
Rule = oldrule
}; !riter.Done; riter.Step())
{
newrule.Patterns[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceObject(riter.PatternAtoms, oldsym, newobj);
newrule.Actions[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceObject(riter.ActionAtoms, oldsym, newobj);
}
newrules.AddRange(ExpandRule(newrule));
}
return(newrules);
}
// limited substitution of pattern direction
IList <AtomicRule> ExpandDirectionSingle(RuleIterator riter, Direction olddir)
{
var newrules = new List <AtomicRule>();
foreach (var newdir in _expanddirlookup[olddir])
{
var newrule = riter.Rule.Clone();
newrule.Patterns[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceDirection(riter.PatternAtoms, olddir, newdir);
if (riter.HasAction)
{
newrule.Actions[riter.SubRuleIndex].Cells[riter.CellIndex] = ReplaceDirection(riter.ActionAtoms, olddir, newdir);
}
newrules.AddRange(ExpandRule(newrule));
}
return(newrules);
}
// expand ambiguous directions in rule pattern known to have no matching action
// replacing by individuals (absolute or relative)
// abs could be fixed by more powerful vm code
IList <AtomicRule> ExpandDirectionSimple(AtomicRule oldrule)
{
for (var riter = new RuleIterator {
Rule = oldrule
}; !riter.Done; riter.Step())
{
// look for any ambiguous unmatched pattern directions, just one each time
var patom = riter.PatternAtoms.FirstOrDefault(a => _expanddirlookup.ContainsKey(a.Direction));
if (patom != null)
{
return(ExpandDirectionSingle(riter, patom.Direction));
}
}
return(new List <AtomicRule> {
oldrule
});
}
// expand a rule where an occurrence on an action does not match its pattern
// replacing combination directions and symbols by individuals (absolute or relative)
// could be fixed by more powerful vm code
IList <AtomicRule> ExpandRule(AtomicRule oldrule)
{
if (!oldrule.HasAction)
{
return(ExpandDirectionSimple(oldrule));
}
// check each cell of each subrule
for (var riter = new RuleIterator {
Rule = oldrule
}; !riter.Done; riter.Step())
{
// Do no expansion on random actions
if (riter.ActionAtoms.Any(a => a.IsRandom))
{
oldrule.Prefixes.Add(RulePrefix.Final);
}
else
{
// check for action atom with ambiguous direction and no matching pattern atom
var datom = riter.ActionAtoms.FirstOrDefault(a => _expanddirlookup.ContainsKey(a.Direction) &&
!riter.PatternAtoms.Any(p => p.Matches(a) && p.Direction == a.Direction));
if (datom != null)
{
return(ExpandDirectionMulti(oldrule, datom.Direction));
}
// check for action atom with property symbol and no matching pattern atom
var satom = riter.ActionAtoms.FirstOrDefault(a => a.Symbol.Kind == SymbolKind.Property &&
!a.IsNegated && !a.IsRandom && !riter.PatternAtoms.Any(p => p.Matches(a)));
if (satom != null)
{
var newrules = ExpandSymbolMulti(oldrule, satom.Symbol) ?? ExpandPropertyMatcher(riter);
if (newrules == null)
{
_parser.CompileError("'{0}' in action cannot be matched", satom.Symbol.Name);
}
else
{
return(newrules);
}
}
}
}
return(ExpandDirectionSimple(oldrule));
}
// look for matching property objects in pattern and action, expand matching pairwise
IList <AtomicRule> ExpandPropertyMatcher(RuleIterator riter)
{
var patom = riter.PatternAtoms.FirstOrDefault(a => a.Symbol.Kind == SymbolKind.Property &&
!a.IsNegated && !a.IsRandom);
var aatom = riter.ActionAtoms.FirstOrDefault(a => a.Symbol.Kind == SymbolKind.Property &&
!a.IsNegated && !a.IsRandom);
if (patom != null && aatom != null && patom.Symbol.ObjectIds.Count == aatom.Symbol.ObjectIds.Count)
{
var newrules = new List <AtomicRule>();
for (int i = 0; i < patom.Symbol.ObjectIds.Count; i++)
{
var newrule = riter.Rule.Clone();
newrule.Prefixes.Add(RulePrefix.Final);
newrule.Patterns[riter.SubRuleIndex].Cells[riter.CellIndex]
= ReplaceObject(riter.PatternAtoms, patom.Symbol, patom.Symbol.ObjectIds[i]);
newrule.Actions[riter.SubRuleIndex].Cells[riter.CellIndex]
= ReplaceObject(riter.ActionAtoms, aatom.Symbol, aatom.Symbol.ObjectIds[i]);
newrules.Add(newrule);
}
return(newrules);
}
return(null);
}
