private static bool TryNonExclusiveQueryEnumeratedParent(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
object key,
LogicVariable v,
ELNodeEnumerator parentEnumerator)
{
// Enumerated parent path
// NonUniqueParent/Something
foundNode = null;
if (v == null)
{
// NonUniqueParent/Key
// Enumerate parent, then do deterministic lookup for child.
enumerator = new ELNodeEnumeratorFixedChildFromParentEnumerator(parentEnumerator, key);
return true;
}
if (parentEnumerator.BindsVar(v))
{
// We're doing a search for a variable that's aready bound.
enumerator = new ELNodeEnumeratorPreboundVariable(parentEnumerator, v, false);
return true;
}
// NonUniqueParent/Variable
// Enumerate both parent and child.
enumerator = new ELNodeEnumeratorLogicVariableFromParentEnumerator(parentEnumerator, v);
return true;
}
public ELNodeEnumeratorBindEnumeratedNodesToVariable(ELNodeEnumerator nodeEnumerator, LogicVariable variableToBind)
{
this.nodeEnumerator = nodeEnumerator;
this.variableToBind = variableToBind;
if (nodeEnumerator.BindsVar(variableToBind))
throw new InvalidOperationException("Variable appears on both the LHS and RHS of >>: "+ variableToBind.Name);
}
private static bool TryExclusiveQueryEnumeratedParent(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
ELNodeEnumerator parentEnumerator,
object key,
LogicVariable v)
{
// Non-deterministic parent path
// NonUniqueParent:Something
foundNode = null;
enumerator = (v == null)
? new ELNodeEnumeratorEnumerateParentAndLookupExclusiveKey(parentEnumerator, key)
: (parentEnumerator.BindsVar(v)? (ELNodeEnumerator)new ELNodeEnumeratorPreboundVariable(parentEnumerator, v, true)
: new ELNodeEnumeratorEnumerateParentAndBindVariable(parentEnumerator, v));
return true;
}
public ELNodeEnumeratorBindEnumeratedNodesToVariable(ELNodeEnumerator nodeEnumerator, LogicVariable variableToBind)
{
this.nodeEnumerator = nodeEnumerator;
this.variableToBind = variableToBind;
if (nodeEnumerator.BindsVar(variableToBind))
throw new InvalidOperationException("Variable appears on both the LHS and RHS of >>: "+ variableToBind.Name);
}
private static bool TryNonExclusiveQueryEnumeratedParent(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
object key,
LogicVariable v,
ELNodeEnumerator parentEnumerator)
{
// Enumerated parent path
// NonUniqueParent/Something
foundNode = null;
if (v == null)
{
// NonUniqueParent/Key
// Enumerate parent, then do deterministic lookup for child.
enumerator = new ELNodeEnumeratorFixedChildFromParentEnumerator(parentEnumerator, key);
return true;
}
if (parentEnumerator.BindsVar(v))
{
// We're doing a search for a variable that's aready bound.
enumerator = new ELNodeEnumeratorPreboundVariable(parentEnumerator, v, false);
return true;
}
// NonUniqueParent/Variable
// Enumerate both parent and child.
enumerator = new ELNodeEnumeratorLogicVariableFromParentEnumerator(parentEnumerator, v);
return true;
}
private static bool TryExclusiveQueryEnumeratedParent(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
ELNodeEnumerator parentEnumerator,
object key,
LogicVariable v)
{
// Non-deterministic parent path
// NonUniqueParent:Something
foundNode = null;
enumerator = (v == null)
? new ELNodeEnumeratorEnumerateParentAndLookupExclusiveKey(parentEnumerator, key)
: (parentEnumerator.BindsVar(v)? (ELNodeEnumerator)new ELNodeEnumeratorPreboundVariable(parentEnumerator, v, true)
: new ELNodeEnumeratorEnumerateParentAndBindVariable(parentEnumerator, v));
return true;
}
public override bool BindsVar(LogicVariable v)
{
return v == this.variable || parentEnumerator.BindsVar(v);
}
public override bool BindsVar(LogicVariable v)
{
return parentEnumerator.BindsVar(v);
}
public override bool BindsVar(LogicVariable v)
{
return v == variableToBind || nodeEnumerator.BindsVar(v);
}