private object EX_While(LispRuntimeCommand cmd, LispList program)
{
object retVal = null;
if (program.items.Count < 2)
{
throw new LispParseException($"'{cmd.CommandName}' command must have at least 1 parameter. Line: {program.line}:{program.position}");
}
LispItem conditionalStatement = program.items[1];
// body of the while loop
start:
object conditionalResult = Run(conditionalStatement);
CheckParameterType(cmd, 1, program, conditionalResult, typeof(bool), false);
if ((bool)conditionalResult)
{
for (int i = 2; i < program.items.Count; i++)
{
retVal = Run(program.items[i]);
}
goto start;
}
return(retVal);
}
private object EX_If(LispRuntimeCommand cmd, LispList program)
{
CheckParameterCount(cmd, program, 2, 3);
LispItem conditionalStatement = program.items[1];
LispItem trueStatement = program.items[2];
// run the condition
object conditionResult = Run(conditionalStatement);
CheckParameterType(cmd, 1, program, conditionResult, typeof(bool), false);
if ((bool)conditionResult)
{
return(Run(trueStatement));
}
else if (program.items.Count == 4)
{
LispItem falseStatement = program.items[3];
return(Run(falseStatement));
}
else
{
return(null);
}
}
public object RunList(LispList program)
{
object result = null;
LispItem first = program.items.First();
if (first is LispSymbol)
{
try
{
LispSymbol sym = first as LispSymbol;
LispRuntimeCommand cmd;
if (_commands.TryGetValue(sym.name, out cmd))
{
result = cmd.Command(cmd, program);
_logger.LogIf(_categories.ScriptLogging, Level.Debug, $"Run {first.line}:{first.position} Cmd:{cmd.CommandName}==>{(result ?? (object)"null")}");
}
else
{
throw new LispParseException($"Unknown command symbol '{sym.name}' Line: {sym.line}:{sym.position}");
}
}
catch (Exception ex)
{
if (!(ex is LispParseException))
{
throw new LispParseException($"{ex.Message} Line {first.line}:{first.position}", ex);
}
else
{
throw;
}
}
}
else if (first is LispList)
{
foreach (LispItem item in program.items)
{
if (item is LispList)
{
result = Run(item as LispList);
}
else
{
throw new LispParseException($"Expected a LispList but got a {item.GetType().Name} Line: {item.line}:{item.position}");
}
}
}
else
{
throw new LispParseException($"Can only execute lists and symbols. Line: {first.line}:{first.position}");
}
return(result);
}
public object Run(LispItem item)
{
object v = null;
switch (item)
{
case LispList ll: v = RunList(ll); break;
case LispString ls: v = ls.value; break;
case LispDouble ld: v = ld.value; break;
case LispInt li: v = li.value; break;
case LispSymbol lsym: v = lsym.name; break;
default: v = null; break;
}
return(v);
}
public T Run <T>(LispItem item)
{
object v = this.Run(item);
return((T)v);
}
