void ExecuteStatement(AbstractSyntaxTree node)
{
if (node == null)
{
return;
}
else if (node.ValueType == ValueTypes.code && node.IsOperand)
{
ApplyRules(AllRules.Where(r => r.Atom == node.Value).ToList()); // WhenPlayBegins;
}
else if (node.ValueType == ValueTypes.code && node.Value == "(" && !node.Contains(FillInThisBlank)) // Heading(Foyer), Description(Foyer)....
{
Rule invokedRule = AllRules.Find(r => r.Atom == node.ToString());
if (invokedRule != null)
{
ApplyRule(invokedRule);
}
else
{
ApplyRules(AllRules.Where(r => r.Atom.StartsWith(node.Left.Value + "(")).ToList(), node.Right);
}
}
else if (node.ValueType == ValueTypes.code && node.Value == "(" && node.Contains(FillInThisBlank)) // understand(_,cloak)
{
foreach (var item in ForEach_(node))
{
ExecuteStatement(item);
}
}
else if (node.ValueType == ValueTypes.code)
{
EvalCode(node);
}
else if (node.ValueType == ValueTypes.text)
{
Console.Write(node.Value);
}
else if (node.ValueType == ValueTypes.number)
{
Console.Write(node.Value);
}
else if (node.ValueType == ValueTypes.boolean)
{
Console.Write(node.Value == "true" ? "yes" : "no");
}
else
{
throw new Exception("We never defined: do " + node.Value + "... ");
}
}
public bool Contains(string atomWithoutParens)
{
if (Value == atomWithoutParens)
{
return(true);
}
if (Left != null && Left.Contains(atomWithoutParens))
{
return(true);
}
if (Right != null && Right.Contains(atomWithoutParens))
{
return(true);
}
return(false);
}
// if the passed-in node is a string value, number, or bool, it returns it. It does NOT auto-print it.
AbstractSyntaxTree EvalCode(AbstractSyntaxTree node)
{
if (node == null)
{
return(null);
}
switch (node.Value) // nodes which are either Operands or mustn't eval both sides immediately
{
case "?":
AbstractSyntaxTree lhs = node.Left;
Rule iteratorVar = new Rule {
Atom = "each", Location = "local", IsPrivateToFile = "local"
};
LocalVariables.Push(new List <Rule>()
{
iteratorVar
});
AllRules.Add(iteratorVar); // todo remove
if (lhs.Value == "(")
{
iteratorVar.Atom += lhs.Left.Value;
}
else
{
lhs = EvalCode(lhs);
}
foreach (AbstractSyntaxTree code in ForEach_(lhs))
{
iteratorVar.Code = code; // set the "eachFoo" variable to the next value in the list
ExecuteStatement(node.Right);
}
LocalVariables.Pop();
AllRules.Remove(iteratorVar); // todo remove
return(null);
case "}":
LocalVariables.Pop();
return(null);
case "Parse":
CrappyHardCodedParser();
return(null);
case null:
return(null);
}
if (node.IsOperand)
{
return(node);
}
AbstractSyntaxTree left = EvalCode(node.Left);
AbstractSyntaxTree right = EvalCode(node.Right);
switch (node.Value) // nodes which will print a value or alter the ruleset
{
case "{":
ExecuteStatement(left);
LocalVariables.Push(new List <Rule>());
ExecuteStatement(right);
return(null);
case ";":
ExecuteStatement(left);
ExecuteStatement(right);
return(null);
case ":=":
var rule = AllRules.FirstOrDefault(r => r.Atom == left.ToString());
if (rule == null)
{
rule = new Rule {
Atom = left.ToString(), Code = right
};
AllRules.Add(rule);
}
if (right.Value == "ReadKeyboard")
{
rule.Code = new AbstractSyntaxTree(Console.ReadLine(), ValueTypes.text);
}
else if (right.Value == "ReadKey")
{
rule.Code = new AbstractSyntaxTree(Console.ReadKey().KeyChar.ToString(), ValueTypes.text);
}
else if (right.Contains("_"))
{
foreach (var item in ForEach_(right))
{
rule.Code = item;
}
}
else
{
rule.Code = right;
}
return(null);
case "(": // we fill-in the values, but don't know if we're going to := assert it or ?{} test it
bool allBound;
return(CloneTreeWithParamsBoundToArgs(node, out allBound));
case ",":
return(node);
}
// at this point, any items of the shape foo(bar,blah) are relations, not function-invocations. We test for existance and value.
if (left.ValueType == ValueTypes.code)
{
left = TestRelation(left);
}
if (right.ValueType == ValueTypes.code)
{
right = TestRelation(right);
}
// these produce a value. Statements (above) do not produce values.
switch (node.Value)
{
case "<": return(Compare(left, right) < 0 ? Yes : No);
case "<=": return(Compare(left, right) <= 0 ? Yes : No);
case "<>":
case "!=": return(Compare(left, right) != 0 ? Yes : No);
case ">": return(Compare(left, right) > 0 ? Yes : No);
case ">=": return(Compare(left, right) >= 0 ? Yes : No);
case "==": return(Compare(left, right) == 0 ? Yes : No);
case "&":
case "&&": return(AsBoolean(left) && AsBoolean(right) ? Yes : No);
case "|":
case "||": return(AsBoolean(left) || AsBoolean(right) ? Yes : No);
case "+": return(new AbstractSyntaxTree((decimal.Parse(left.Value) + decimal.Parse(right.Value)).ToString(), ValueTypes.number));
case "-": return(new AbstractSyntaxTree((decimal.Parse(left.Value) - decimal.Parse(right.Value)).ToString(), ValueTypes.number));
case "*": return(new AbstractSyntaxTree((decimal.Parse(left.Value) * decimal.Parse(right.Value)).ToString(), ValueTypes.number));
case "/": return(new AbstractSyntaxTree((decimal.Parse(left.Value) / decimal.Parse(right.Value)).ToString(), ValueTypes.number));
}
return(node);
}