private object ExecuteInfix (Element elem) {
object[] args = CollectArgs (elem.Children);
double a = (double) args[0];
double b = (double) args[1];
switch ((char) elem.Val) {
case '+':
return a + b;
case '-':
return a - b;
case '*':
return a * b;
case '/':
return a / b;
case '^':
return Math.Pow (a, b);
case '=':
return a == b;
case '<':
return a < b;
case '>':
return a > b;
default:
throw new Exception ();
}
}
private object ExecuteStatement (Element elem) {
object ret = null;
object[] args = CollectArgs (elem.Children);
context.CallingEngine = this;
ret = stores.SendMessage (context, (string) elem.Val, args);
context.CallingEngine = null;
return ret;
}
private void CompileBareList (Element elem)
{
int i = elem.Children.Count - 1;
foreach (Element subelem in elem.Children) {
Compile (subelem);
if (i > 0)
writer.Write (", ");
i--;
}
}
protected override void CompileStatement (Element elem) {
statement_level++;
Type[] arg_types = CollectTypes (elem);
if (stores.SupportsMessage ((string) elem.Val, arg_types)) {
CompileTypedStatement (elem, arg_types);
} else {
CompileGenericStatement (elem);
}
statement_level--;
if (statement_level == 0) {
writer.WriteLine (";");
}
}
protected override void CompileInfix (Element elem) {
char op = (char) elem.Val;
if (op == '^') {
writer.Write ("System.Math.Pow (");
CompileInfixArg (elem.Children[0]);
writer.Write (", ");
CompileInfixArg (elem.Children[1]);
writer.Write (")");
return;
}
CompileInfixArg (elem.Children[0]);
if (op == '=')
writer.Write ("==");
else
writer.Write (op);
CompileInfixArg (elem.Children[1]);
}
public void Compile (Element elem) {
switch (elem.Type) {
case ElementType.Literal:
CompileLiteral (elem);
break;
case ElementType.List:
CompileList (elem);
break;
case ElementType.Statement:
CompileStatement (elem);
break;
case ElementType.Infix:
CompileInfix (elem);
break;
case ElementType.Variable:
CompileVariable (elem);
break;
default:
throw new Exception ();
}
}
protected abstract void CompileVariable (Element elem);
protected abstract void CompileLiteral (Element elem);
protected abstract void CompileList (Element elem);
protected abstract void CompileInfix (Element elem);
protected abstract void CompileStatement (Element elem);
public void Insert (int index, Element elem) {
List.Insert (index, elem);
}
private Type[] CollectTypes (Element elem) {
return null;
}
protected override void CompileList (Element elem)
{
writer.Write ("new object[] {");
CompileBareList (elem);
writer.Write ("}");
}
private void CompileInfixArg (Element elem) {
writer.Write ("((double) ");
Compile (elem);
writer.Write (")");
}
private void CompileTypedStatement (Element elem, Type[] arg_types) {
writer.Write ("Funcs.{0} (", elem.Val);
CompileBareList (elem);
writer.Write (")");
}
private void CompileGenericStatement (Element elem) {
writer.Write ("_funcs.SendMessage (_context, \"{0}\", ", elem.Val);
CompileList (elem);
writer.Write (")");
}
protected override void CompileLiteral (Element elem)
{
object val = elem.Val;
if (val is string)
writer.Write ("\"{0}\"", val);
else if (val is char)
writer.Write ("'{0}'", val);
else
writer.Write (val);
}
public int Add (Element elem) {
return List.Add (elem);
}
private object ConstructList (Element elem) {
object[] list = new object[elem.Children.Count];
int i = 0;
foreach (Element subelem in elem.Children) {
if (subelem.Type == ElementType.List)
list[i] = ConstructList (subelem);
else
list[i] = subelem.Val;
i++;
}
return list;
}
protected override void CompileVariable (Element elem)
{
writer.Write ("Funcs.Thing (_context, \"{0}\")", (string) elem.Val);
}
