public static IArgument Number(CharSource source, ref char chr)
{
var integral = source.ReadInt(ref chr);
if (chr == '.')
{
if (!source.Advance(out chr))
{
throw new FinalCharacterException("Expected fractional value after '.'");
}
else if (!char.IsDigit(chr))
{
throw new InvalidCharacterException($"Expected fractional value after '.': found '{chr}'");
}
var fractional = source.ReadFractional(ref chr);
var mantissa = integral >= 0 ? integral + fractional : integral - fractional;
if (char.ToLower(chr) == 'e')
{
if (!source.AdvanceWhiteSpace(out chr))
{
throw new FinalCharacterException("Expected exponent after 'e'");
}
else if (!CharSource.IsNumberStart(chr))
{
throw new InvalidCharacterException($"Expected exponent after 'e': found '{chr}'");
}
var exponent = source.ReadInt(ref chr);
mantissa *= Math.Pow(10, exponent);
}
return(new DoubleLiteral()
{
Value = mantissa
});
}
return(new IntegerLiteral()
{
Value = integral
});
}
public static IArgument Default(CharSource source, ref char chr)
{
if (CharSource.IsNameStart(chr))
{
var name = source.ReadName(ref chr);
if (bool.TryParse(name, out var bval))
{
return(new BooleanLiteral()
{
Value = bval
});
}
return(new NameArgument()
{
Value = name
});
}
else if (CharSource.IsNumberStart(chr))
{
return(Number(source, ref chr));
}
throw new InvalidCharacterException($"Not a valid name or number start: '{chr}'");
}
