public override string ToString(bool printReadably)
{
if (ast != null)
{
return("<fn " + Printer.pr_str(fparams, true) +
" " + Printer.pr_str(ast, true) + ">");
}
else
{
return("<builtin_function " + fn.ToString() + ">");
}
}
static MalVal EVAL(MalVal ast, Dictionary <string, MalFunc> replEnv)
{
switch ((Object)ast)
{
case MalList mList:
// Ast is a list.
// TODO - should this also do vectors and hashmaps?
if (mList.Count() <= 0)
{
// Empty list, return unchanged.
Console.WriteLine("EVAL - empty list: " + Printer.pr_str(mList, true));
return(ast);
}
else
{
// ast is a non-empty list, so evaluate it.
Console.WriteLine("EVAL - non-empty list: " + Printer.pr_str(mList, true));
// Evaluate the List.
MalList evaledList = (MalList)eval_ast(ast, replEnv);
MalVal listFirst = evaledList.First();
MalList listRest = evaledList.Rest();
switch ((Object)listFirst)
{
case MalFunc func:
Console.WriteLine("EVAL - List head is: '" + Printer.pr_str(listFirst, true) + "'. Rest elements: ");
// Take the first item of the evaluated list and call it as function using the rest of the evaluated list as its arguments
return(func.Apply(listRest));
//return null;
default:
throw new MalEvalError("Can't use '" + listFirst.ToString(true) + "' as a function.");
}
}
default:
// If ast is not a list (e.g. a vector), return the result of calling eval_ast on it.
return(eval_ast(ast, replEnv));
}
}
String PRINT(MalVal exp)
{
return(Printer.pr_str(exp, true));
}
// Call the stored func, passing it a list containing args, if any.
public MalVal Apply(MalList args)
{
Console.WriteLine("In Apply: " + Printer.pr_str(args, true));
return(fn(args));
}