/// <summary>
/// Evalues an AST in the environment.
///
/// TODO: refactor to move to <see cref="OpenLisp.Core.StaticClasses.CoreNameSpace"/>.
/// </summary>
/// <param name="abstractSyntaxTree"></param>
/// <param name="environment"></param>
/// <returns></returns>
public static OpenLispVal EvalAst(OpenLispVal abstractSyntaxTree, Env environment)
{
var key = abstractSyntaxTree as OpenLispSymbol;
if (key != null)
{
return(environment.Get(key));
}
var list = abstractSyntaxTree as OpenLispList;
if (list == null)
{
var map = abstractSyntaxTree as OpenLispHashMap;
if (map == null)
{
return(abstractSyntaxTree);
}
var newDictionary =
map.Value.ToDictionary(
entry => entry.Key, entry => Eval(entry.Value, environment));
return(new OpenLispHashMap(newDictionary));
}
OpenLispList oldList = list;
OpenLispList newList = abstractSyntaxTree.ListQ() ? new OpenLispList()
: (OpenLispList) new OpenLispVector();
foreach (OpenLispVal movedValue in oldList.Value)
{
newList.Conj(Eval(movedValue, environment));
}
return(newList);
}
/// <summary>
/// Reads an OpenLisp.NET list expression.
/// </summary>
/// <param name="reader"></param>
/// <param name="openLispList"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
public static OpenLispVal ReadList(TokensReader reader, OpenLispList openLispList, char start, char end)
{
string token = reader.Next();
if (token[0] == start)
{
while ((token = reader.Peek()) != null && token[0] != end)
{
openLispList.Conj(ReadForm(reader));
}
if (token == null)
{
throw new ParseError("expected '" + end + "', got EOF");
}
reader.Next();
return(openLispList);
}
throw new ParseError("expected '" + start + "'");
}