static public MalVal read_str_multiline(Reader rdr)
{
return(read_form(rdr));
}
static public MalVal read_atom(Reader reader)
{
// "If you have a problem and you think regex is the answer, now you have two problems!"
// Unlike the referenceC#-Mal, read_atom handles floats and badly-formed symbols.
string tokenToRead = reader.Next();
if (tokenToRead.Length <= 0)
{
throw new MalInternalError("Reader has returned empty string");
}
switch (tokenToRead[0])
{
case '+':
if (tokenToRead.Length == 1)
{
// Token is a solo '+', not the beginning of a number.
return(new MalSym(tokenToRead));
}
// Skip the sign and extract a positive number;
return(ParseNumber(tokenToRead.Substring(1), true));
case '-':
if (tokenToRead.Length == 1)
{
// Token is a solo '-', not the beginning of a number.
return(new MalSym(tokenToRead));
}
// Skip the sign and extract a negative number;
return(ParseNumber(tokenToRead.Substring(1), false));
case '.':
// An initial '.' is only allowed at the start of a number, as in '.2'.
return(ParseNumber(tokenToRead, true));
case '\"':
if (tokenToRead.EndsWith("\""))
{
return(new MalString(tokenToRead));
}
// TODO - never reaches this point. The reader regex seems to throw away '"' chars if there is only 1.
throw new MalParseError("String '" + tokenToRead + "' lacks a closing thingy");
case ':':
// Handle a keyword
if (tokenToRead.Length == 1)
{
// Can't have a solo colon.
throw new MalParseError("':' must be followed by a keyword");
}
return(new MalKeyword(tokenToRead));
default:
if (IsDigit(tokenToRead[0].ToString()))
{
// Token seems to be an unsigned number.
return(ParseNumber(tokenToRead, true));
}
else if (tokenToRead == "nil")
{
return(malNil);
}
else if (tokenToRead == "true")
{
return(malTrue);
}
else if (tokenToRead == "false")
{
return(malFalse);
}
else
{
// If here it is 'just' a symbol.
return(new MalSym(tokenToRead));
}
}
throw new MalInternalError("Can't process '" + tokenToRead + "'");
}