// two arguments primitive.
// more that two arguments will be raped to list of primitives
// (foo 1 2)
public static AST Expand(Syntax stx, Environment env)
{
var list = stx.AsLinkedList <Value>();
var argc = GetArgsCount(list);
AssertArgsMinimum("primitive2", "arity mismatch", 2, argc, list, stx);
var set_kwd = list[0].AsSyntax();
var arguments = AstBuilder.ExpandListElements(list, 1, env);
if (argc == 2)
{
return(new AstPrimitive(stx, set_kwd, arguments));
}
else
{
// for expression (+ 1 2 3 4)
var args = arguments.DuplicateReverse(0, -1); //< (+ 4 3 2 1)
var rightarg = args[0]; //< 4
var skip = 1;
foreach (var leftarg in args) //< 3, 2, 1,
{
if (skip-- > 0)
{
continue;
}
var values = ValueLinkedList.FromArguments(leftarg, rightarg);
var prim = new AstPrimitive(stx, set_kwd, values);
rightarg.Set(prim);
}
return(rightarg.AsAST());
}
}
public void LinkedListTest()
{
string expect = "(1 2 3.1)";
LinkedList <Value> x1 = ValueLinkedList.FromArguments(1, 2, 3.1);
Value a1 = new Value(x1);
Assert.AreEqual(expect, x1.ToString());
Assert.AreEqual(expect, a1.ToString());
}
public void LinkedListTest()
{
LinkedList <Value> x1 = ValueLinkedList.FromArguments(1, 2, 3);
LinkedList <Value> x2 = ValueLinkedList.FromArguments(4, 5, 6);
Value a1 = new Value(x1);
Value a2 = new Value(x2);
Value b1 = new Value(x1);
Value b2 = new Value(x2);
Assert.AreEqual(x1, (LinkedList <Value>)a1);
Assert.AreEqual(x2, (LinkedList <Value>)a2);
Assert.AreEqual(a1, b1);
Assert.AreEqual(a2, b2);
Assert.AreNotEqual(a1, a2);
Assert.AreNotEqual(b1, b2);
Assert.AreNotEqual(x1, (LinkedList <Value>)a2);
Assert.AreNotEqual(x2, (LinkedList <Value>)a1);
}
// (cond () ...)
public static AST Expand(Syntax stx, Environment env)
{
var list = stx.AsLinkedList <Value>(); //< list of syntax objects
var argc = GetArgsCount(list);
var keyword = list[0].AsSyntax();
LinkedList <Value> allcases = null;
LinkedList <Value> elsecase = null;
var curent = list.GetNodeAtIndex(1);
while (curent != null)
{
var conditional_stx = curent.Value.AsSyntax();
if (elsecase != null)
{
throw SchemeError.SyntaxError("cond", "unexpected expression after condition's else clause", conditional_stx);
}
if (conditional_stx.IsExpression)
{
// Get single conditional expression
var conditional_list = conditional_stx.AsLinkedList <Value>();
// Check arguments count, should be 2 for each condition
var size = conditional_list.Count;
if (size != 2)
{
throw SchemeError.ArityError("cond", "arity mismatch", 2, size, conditional_list, conditional_stx);
}
// Now get condition and it's expression
var var = conditional_list[0].AsSyntax();
var val = conditional_list[1].AsSyntax();
if (var.IsIdentifier && var.AsIdentifier() == Symbol.ELSE)
{
var ast = AstBuilder.ExpandInternal(val, env);
elsecase = ValueLinkedList.FromArguments(new Value(var), new Value(ast));
}
else
{
var cond_ = AstBuilder.ExpandInternal(var, env);
var then_ = AstBuilder.ExpandInternal(val, env);
var single_cond = ValueLinkedList.FromArguments(cond_, then_);
if (allcases == null)
{
allcases = new LinkedList <Value>();
}
allcases.AddLast(new Value(single_cond));
}
}
else
{
throw SchemeError.SyntaxError("cond", "Expected condition's expression list", conditional_stx);
}
curent = curent.Next;
}
return(new AstCondition(stx, keyword, allcases, elsecase));
}