public ClSymbol Read(ISource source)
{
if (source.Eof())
{
return(null);
}
if (TryCheckSpecialBuiltInFunction(source, out var fun))
{
return(new ClSymbol(fun));
}
var ch = (char)source.Peek();
if (!char.IsLetter(ch))
{
return(null);
}
string loop(string acc)
{
if (source.Eof())
{
return(acc);
}
var ch = (char)source.Peek();
if (!char.IsLetterOrDigit(ch) && ch != '-' && ch != '?' && ch != '!')
{
return(acc);
}
return(loop($"{acc}{(char) source.Read()}"));
}
return(new ClSymbol(loop($"{(char) source.Read()}")));
}
public ClObj Read(ISource source)
{
var items = new List <ClObj> {
ClSymbol.Begin
};
while (!source.Eof())
{
source.RewindSpacesAndComments();
items.Add(_reader.Read(source));
source.RewindSpacesAndComments();
}
return(BuiltIn.ListOf(items));
}
public ClObj Read(ISource source)
{
if (source.Eof())
{
return(ClCell.Nil);
}
foreach (var reader in _readers)
{
if (reader.Read(source) is ClObj obj)
{
return(obj);
}
}
throw new SyntaxError("Unknown literal");
}
protected bool TryReadAtLeastOneNumber(ISource source, out string nums)
{
string loop(string acc = "")
{
if (source.Eof())
{
return(acc);
}
if (!char.IsDigit((char)source.Peek()))
{
return(acc);
}
return(loop($"{acc}{(char) source.Read()}"));
}
nums = loop();
return(!string.IsNullOrEmpty(nums));
}
public ClChar Read(ISource source)
{
if (!source.Rewind(@"#\"))
{
return(null);
}
foreach (var(word, ch) in SpecialChars)
{
if (!source.Rewind(word))
{
continue;
}
return(new ClChar(ch));
}
if (source.Eof())
{
throw new SyntaxError($"Invalid format of the {nameof(ClChar)} literal");
}
return(new ClChar((char)source.Read()));
}
public static bool RewindSpaces(this ISource source)
{
bool loop(bool atLeastOne = false)
{
if (source.Eof())
{
return(atLeastOne);
}
var code = source.Read();
if (char.IsWhiteSpace((char)code))
{
return(loop(true));
}
source.Buffer(code);
return(atLeastOne);
}
return(loop());
}
public ClString Read(ISource source)
{
if (!source.Rewind("'"))
{
return(null);
}
string loop(string acc)
{
if (source.Eof())
{
throw new SyntaxError($"Invalid format of the {nameof(ClString)} literal");
}
var ch = (char)source.Read();
if (ch == '\'')
{
return(acc);
}
return(loop($"{acc}{ch}"));
}
return(new ClString(loop(string.Empty)));
}
