// routines related to "reconstructing" the syntax tree from the saved tokens to do context checks
/// <summary>
/// Returns the context object for the given token index, ignoring empty fragments.
/// Throws an ArgumentNullException if the given token index is null.
/// </summary>
private static Context.SyntaxTokenContext GetContext(this CodeFragment.TokenIndex tokenIndex)
{
if (tokenIndex == null)
{
throw new ArgumentNullException(nameof(tokenIndex));
}
QsNullable <QsFragmentKind> Nullable(CodeFragment fragment) =>
fragment?.Kind == null
? QsNullable <QsFragmentKind> .Null
: fragment.IncludeInCompilation
? QsNullable <QsFragmentKind> .NewValue(fragment.Kind)
: QsNullable <QsFragmentKind> .NewValue(QsFragmentKind.InvalidFragment);
var self = tokenIndex.GetFragment();
var previous = tokenIndex.PreviousOnScope()?.GetFragment(); // excludes empty tokens
var next = tokenIndex.NextOnScope()?.GetFragment(); // excludes empty tokens
var parents = tokenIndex.GetNonEmptyParents().Select(tIndex => Nullable(tIndex.GetFragment())).ToArray();
var nullableSelf = self?.Kind == null // special treatment such that errors for fragments excluded from compilation still get logged...
? QsNullable <QsFragmentKind> .Null
: QsNullable <QsFragmentKind> .NewValue(self.Kind);
var headerRange = self?.HeaderRange ?? QsCompilerDiagnostic.DefaultRange;
return(new Context.SyntaxTokenContext(headerRange, nullableSelf, Nullable(previous), Nullable(next), parents));
}
/// <summary>
/// Returnes an IEnumerable with the indices of all children of the given token.
/// If deep is set to true (default value), then the returned children are all following tokens
/// with a higher indentation level than the token corresponding to tIndex
/// up to the point where we are at the same indentation level again.
/// If deep is set to false, then of those only the tokens with an indentation level that is precisely
/// one larger than the one of the parent token are returned.
/// Throws an ArgumentNullException if tIndex is null.
/// </summary>
internal static IEnumerable <CodeFragment.TokenIndex> GetChildren(this CodeFragment.TokenIndex tIndex, bool deep = true)
{
if (tIndex == null)
{
throw new ArgumentNullException(nameof(tIndex));
}
var tokenIndex = new CodeFragment.TokenIndex(tIndex);
var indentation = tokenIndex.GetFragment().Indentation;
while (++tokenIndex != null && tokenIndex.GetFragment().Indentation > indentation)
{
if (deep || tokenIndex.GetFragment().Indentation == indentation + 1)
{
yield return(tokenIndex);
}
}
}
/// <summary>
/// Returns the index of the next non-empty token on the same indenation level, or null if no such token exists.
/// Includes empty tokens if includeEmpty is set to true.
/// Throws an ArgumentNullException if tIndex is null.
/// </summary>
internal static CodeFragment.TokenIndex NextOnScope(this CodeFragment.TokenIndex tIndex, bool includeEmpty = false)
{
if (tIndex == null)
{
throw new ArgumentNullException(nameof(tIndex));
}
var tokenIndex = new CodeFragment.TokenIndex(tIndex);
var indentation = tokenIndex.GetFragment().Indentation;
while (++tokenIndex != null)
{
var fragment = tokenIndex.GetFragment();
if (fragment.Indentation <= indentation && (fragment.Kind != null || includeEmpty))
{
break;
}
}
return(tokenIndex != null && tokenIndex.GetFragment().Indentation == indentation ? tokenIndex : null);
}
/// <summary>
/// Returns the index of the closest preceding non-empty token with the next lower indentation level.
/// Returns null if no such token exists.
/// Throws an ArgumentNullException if tIndex is null.
/// </summary>
private static CodeFragment.TokenIndex GetNonEmptyParent(this CodeFragment.TokenIndex tIndex)
{
if (tIndex == null)
{
throw new ArgumentNullException(nameof(tIndex));
}
var tokenIndex = new CodeFragment.TokenIndex(tIndex);
var indentation = tokenIndex.GetFragment().Indentation;
while (--tokenIndex != null)
{
var fragment = tokenIndex.GetFragment();
if (fragment.Kind != null && fragment.Indentation < indentation)
{
break; // ignore empty fragments
}
}
return(tokenIndex != null && tokenIndex.GetFragment().Indentation == indentation - 1 ? tokenIndex : null);
}
// routines related to "reconstructing" the syntax tree from the saved tokens to do context checks
/// <summary>
/// Returns the context object for the given token index, ignoring empty fragments.
/// </summary>
private static Context.SyntaxTokenContext GetContext(this CodeFragment.TokenIndex tokenIndex)
{
QsNullable <QsFragmentKind> Nullable(CodeFragment?token, bool precedesSelf) =>
token?.Kind == null
? QsNullable <QsFragmentKind> .Null
: precedesSelf && !token.IncludeInCompilation // fragments that *follow * self need to be re-evaluated first
? QsNullable <QsFragmentKind> .NewValue(QsFragmentKind.InvalidFragment)
: QsNullable <QsFragmentKind> .NewValue(token.Kind);
var fragment = tokenIndex.GetFragment();
var headerRange = fragment?.HeaderRange ?? Range.Zero;
var self = Nullable(fragment, false); // making sure that errors for fragments excluded from compilation still get logged
var previous = Nullable(tokenIndex.PreviousOnScope()?.GetFragment(), true); // excludes empty tokens
var next = Nullable(tokenIndex.NextOnScope()?.GetFragment(), false); // excludes empty tokens
var parents = tokenIndex.GetNonEmptyParents().Select(tIndex => Nullable(tIndex.GetFragment(), true)).ToArray();
return(new Context.SyntaxTokenContext(headerRange, self, previous, next, parents));
}