/// <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 + "'");
}
/// <summary>
/// Reads an OpenLisp.NET atom.
/// </summary>
/// <param name="reader"></param>
/// <returns></returns>
public static OpenLispVal ReadAtom(TokensReader reader)
{
string token = reader.Next();
string pattern = @"(^-?[0-9]+$)|(^-?[0-9][0-9.]*$)|(^nil$)|(^true$)|(^false$)|^("".*"")$|:(.*)|(^[^""]*$)";
Regex regex = new Regex(pattern);
Match match = regex.Match(token);
//Console.WriteLine("token: ^" + token + "$");
if (!match.Success)
{
throw new ParseError("unrecognized token '" + token + "'");
}
if (match.Groups[1].Value == String.Empty)
{
if (match.Groups[3].Value == String.Empty)
{
if (match.Groups[4].Value == String.Empty)
{
if (match.Groups[5].Value == String.Empty)
{
if (match.Groups[6].Value == String.Empty)
{
if (match.Groups[7].Value == String.Empty)
{
if (match.Groups[8].Value == String.Empty)
{
throw new ParseError("unrecognized '" + match.Groups[0] + "'");
}
return(new OpenLispSymbol(match.Groups[8].Value));
}
return(new OpenLispString("\u029e" + match.Groups[7].Value));
}
string str = match.Groups[6].Value;
str = str.Substring(1, str.Length - 2)
.Replace("\\\"", "\"")
.Replace("\\n", "\n");
return(new OpenLispString(str));
}
return(StaticOpenLispTypes.False);
}
return(StaticOpenLispTypes.True);
}
return(StaticOpenLispTypes.Nil);
}
return(new OpenLispInt(int.Parse(match.Groups[1].Value)));
}
/// <summary>
/// This static method recursively processes
/// OpenLisp.NET forms and tokenizes them.
/// </summary>
/// <param name="reader"></param>
/// <returns></returns>
public static OpenLispVal ReadForm(TokensReader reader)
{
string token = reader.Peek();
if (token == null)
{
throw new OpenLispContinue();
}
OpenLispVal form = null;
switch (token)
{
case "'":
reader.Next();
return(new OpenLispList(new OpenLispSymbol("quote"),
ReadForm(reader)));
case "`":
reader.Next();
return(new OpenLispList(new OpenLispSymbol("quasiquote"),
ReadForm(reader)));
case "~":
reader.Next();
return(new OpenLispList(new OpenLispSymbol("unquote"),
ReadForm(reader)));
case "~@":
reader.Next();
return(new OpenLispList(new OpenLispSymbol("splice-unquote"),
ReadForm(reader)));
case "^":
reader.Next();
OpenLispVal meta = ReadForm(reader);
return(new OpenLispList(new OpenLispSymbol("with-meta"),
ReadForm(reader),
meta));
case "@":
reader.Next();
return(new OpenLispList(new OpenLispSymbol("deref"),
ReadForm(reader)));
case "(": form = ReadList(reader, new OpenLispList(), '(', ')'); break;
case ")": throw new ParseError("unexpected ')'");
case "[": form = ReadList(reader, new OpenLispVector(), '[', ']'); break;
case "]": throw new ParseError("unexpected ']'");
case "{": form = ReadHashMap(reader); break;
case "}": throw new ParseError("unexpected '}'");
default: form = ReadAtom(reader); break;
}
return(form);
}
