public TableValue <TState, TSymbol> this[TableKey <TState, TSymbol> key]
{
get
{
if (!States.Contains(key.State))
{
throw new ArgumentException(nameof(key.State));
}
if (!Symbols.Contains(key.Symbol))
{
throw new ArgumentException(nameof(key.Symbol));
}
return(_table[key]);
}
set
{
if (!States.Contains(key.State))
{
throw new ArgumentException(nameof(key.State));
}
if (!Symbols.Contains(key.Symbol))
{
throw new ArgumentException(nameof(key.Symbol));
}
if (!States.Contains(value.State))
{
throw new ArgumentException(nameof(value.State));
}
if (!Symbols.Contains(value.Symbol))
{
throw new ArgumentException(nameof(value.Symbol));
}
_table[key] = value;
}
}
public static StatefulTable <TState, TSymbol> Load <TState, TSymbol>(XDocument document, TSymbol nullValue,
StateSerializer <TState> stateSerializer, SymbolSerializer <TSymbol> symbolSerializer)
{
// Get symbols
var symbols = new List <TSymbol>();
symbols.Add(nullValue);
foreach (var element in document.Root.Elements())
{
if ("symbols".Equals(element.Name.LocalName))
{
for (int index = 0; index < element.Value.Length; index++)
{
symbols.Add(symbolSerializer.FromString($"{element.Value[index]}"));
}
break;
}
}
// Get status
var states = new List <TState>();
var initialState = default(TState);
var finalStates = new List <TState>();
foreach (var element in document.Root.Elements())
{
if ("states".Equals(element.Name.LocalName))
{
foreach (var stateTag in element.Elements())
{
bool isStart = false;
bool isHalt = false;
if ("state".Equals(stateTag.Name.LocalName))
{
foreach (var attribute in stateTag.Attributes())
{
if ("start".Equals(attribute.Name.LocalName))
{
isStart = "yes".Equals(attribute.Value);
}
else if ("halt".Equals(attribute.Name.LocalName))
{
isHalt = "yes".Equals(attribute.Value);
}
}
var status = stateSerializer.FromString(stateTag.Value);
states.Add(status);
if (isStart)
{
initialState = status;
}
if (isHalt)
{
finalStates.Add(status);
}
}
}
break;
}
}
// Create the table
var table = new StatefulTable <TState, TSymbol>(states, symbols, initialState, finalStates);
// Transition function
foreach (var element in document.Root.Elements())
{
if ("transition-function".Equals(element.Name.LocalName))
{
foreach (var mappingTag in element.Elements())
{
if ("mapping".Equals(mappingTag.Name.LocalName))
{
var currentState = string.Empty;
var currentSymbol = string.Empty;
var nextState = string.Empty;
var nextSymbol = string.Empty;
var movement = string.Empty;
foreach (var fromTag in mappingTag.Elements())
{
if ("from".Equals(fromTag.Name.LocalName))
{
foreach (var attribute in fromTag.Attributes())
{
if ("current-state".Equals(attribute.Name.LocalName))
{
currentState = attribute.Value;
}
else if ("current-symbol".Equals(attribute.Name.LocalName))
{
currentSymbol = attribute.Value;
}
}
break;
}
}
foreach (var toTag in mappingTag.Elements())
{
if ("to".Equals(toTag.Name.LocalName))
{
foreach (var attribute in toTag.Attributes())
{
if ("next-state".Equals(attribute.Name.LocalName))
{
nextState = attribute.Value;
}
else if ("next-symbol".Equals(attribute.Name.LocalName))
{
nextSymbol = attribute.Value;
}
else if ("movement".Equals(attribute.Name.LocalName))
{
movement = attribute.Value;
}
}
break;
}
}
var key = new TableKey <TState, TSymbol>(stateSerializer.FromString(currentState),
symbolSerializer.FromString(currentSymbol));
var value = new TableValue <TState, TSymbol>(stateSerializer.FromString(nextState),
symbolSerializer.FromString(nextSymbol), GetMoveActionFromString(movement));
table[key] = value;
}
}
break;
}
}
return(table);
}
