private static bool IntegerTerminatorPredicate(char c)
{
if (LexingHelper.IsInlineWhiteSpaceOrCaretControl(c))
{
return(true);
}
if (TinyLispHelper.IsPunctuation(c))
{
return(true);
}
return(false);
}
public static PseudoList GetAllKeywordArguments(
this Element shouldBePseudoList,
string argumentName,
bool absenceIsAllowed = false)
{
if (shouldBePseudoList == null)
{
throw new ArgumentNullException(nameof(shouldBePseudoList));
}
var list = shouldBePseudoList as PseudoList;
if (list == null)
{
throw new ArgumentException(
$"Argument is not of type '{typeof(PseudoList).FullName}'.",
nameof(shouldBePseudoList));
}
if (argumentName == null)
{
throw new ArgumentNullException(nameof(argumentName));
}
if (!TinyLispHelper.IsValidSymbolName(argumentName, true))
{
throw new ArgumentException($"'{argumentName}' is not a valid keyword.", nameof(argumentName));
}
var wantedKeyword = Symbol.Create(argumentName);
var index = list.FindFirstIndex(wantedKeyword);
if (index == -1)
{
if (absenceIsAllowed)
{
return(new PseudoList()); // empty
}
else
{
throw new TinyLispException($"No argument for keyword '{argumentName}'.");
}
}
index++; // move forward from keyword.
var startIndex = index;
while (true)
{
if (index == list.Count)
{
break;
}
var element = list[index];
if (element is Keyword)
{
break;
}
index++;
}
var lastIndex = index - 1;
var result = new PseudoList();
for (var i = startIndex; i <= lastIndex; i++)
{
result.AddElement(list[i]);
}
return(result);
}
public static Element GetSingleKeywordArgument(
this Element shouldBePseudoList,
string argumentName,
bool absenceIsAllowed = false)
{
if (shouldBePseudoList == null)
{
throw new ArgumentNullException(nameof(shouldBePseudoList));
}
var list = shouldBePseudoList as PseudoList;
if (list == null)
{
throw new ArgumentException(
$"Argument is not of type '{typeof(PseudoList).FullName}'.",
nameof(shouldBePseudoList));
}
if (argumentName == null)
{
throw new ArgumentNullException(nameof(argumentName));
}
if (!TinyLispHelper.IsValidSymbolName(argumentName, true))
{
throw new ArgumentException($"'{argumentName}' is not a valid keyword.", nameof(argumentName));
}
var wantedKeyword = Symbol.Create(argumentName);
int wantedIndex;
var index = list.FindFirstIndex(wantedKeyword);
if (index < 0)
{
if (absenceIsAllowed)
{
return(null);
}
else
{
throw new TinyLispException($"No argument for keyword '{argumentName}'.");
}
}
else
{
wantedIndex = index + 1;
}
if (wantedIndex == list.Count)
{
throw new TinyLispException($"Keyword '{argumentName}' was found, but at the end of the list.");
}
var wantedElement = list[wantedIndex];
if (wantedElement is Keyword)
{
throw new TinyLispException($"Keyword '{argumentName}' was found, but next element is a keyword too.");
}
return(wantedElement);
}
