public virtual void EvaluateUserTerm(ForthState state)
{
foreach (var definition in state.Mapping[Term])
{
definition.Evaluate(state);
}
}
public override void EvaluateDefaultTerm(ForthState state)
{
if (!state.Mapping.ContainsKey(Term))
{
throw new InvalidOperationException();
}
}
public override void EvaluateDefaultTerm(ForthState state)
{
if (!state.Mapping.ContainsKey(Term))
{
throw new ForthException(ForthError.UnknownWord);
}
}
private ForthState()
{
if (_instance != null)
{
return;
}
_instance = this;
}
public override void Evaluate(ForthState state)
{
if (IsUserTerm(state))
{
EvaluateUserTerm(state);
}
else
{
EvaluateDefaultTerm(state);
}
}
public override void Evaluate(ForthState state)
{
int result;
if (int.TryParse(term, out result))
{
throw new ForthException(ForthError.InvalidWord);
}
state.Mapping[term] = actions;
}
public static string Eval(string input)
{
var expression = Expression.Parse(input);
var state = new ForthState();
foreach (var definition in expression)
{
definition.Evaluate(state);
}
return(state.ToString());
}
public override void EvaluateDefaultTerm(ForthState state)
{
if (state.Stack.Count < 1)
{
throw new InvalidOperationException();
}
var operand = state.Stack.Pop();
foreach (var value in operation(operand))
{
state.Stack.Push(value);
}
}
public override void EvaluateDefaultTerm(ForthState state)
{
if (state.Stack.Count <= 1)
{
throw new ForthException(ForthError.StackUnderflow);
}
var operand2 = state.Stack.Pop();
var operand1 = state.Stack.Pop();
foreach (var value in operation(operand1, operand2))
{
state.Stack.Push(value);
}
}
public static string Evaluate(string[] instructions)
{
var state = new ForthState();
foreach (var instruction in instructions)
{
var expression = Expression.Parse(instruction);
foreach (var definition in expression)
{
definition.Evaluate(state);
}
}
return(state.ToString());
}
public override void Evaluate(ForthState state)
{
if (int.TryParse(term, out _))
{
throw new InvalidOperationException();
}
var normalizedActions = new List <ForthDefinition>();
foreach (var action in actions)
{
if (action is Word word)
{
normalizedActions.AddRange(state.Mapping[word.Term]);
}
else
{
normalizedActions.Add(action);
}
}
state.Mapping[term] = normalizedActions;
}
public abstract void EvaluateDefaultTerm(ForthState state);
private bool IsUserTerm(ForthState state) => state.Mapping.ContainsKey(Term);
public abstract void Evaluate(ForthState state);
public override void Evaluate(ForthState state) => state.Stack.Push(n);
