private IEnumerable <SyntaxTrivia> TriviaResolver(
TriviaLocation location,
PreviousNextTokenPair tokenPair,
Dictionary <SyntaxToken, LeadingTrailingTriviaPair> triviaMap,
MethodDeclarationSyntax method)
{
// Resolve trivia at the edge of the selection. simple case is easy to deal with, but complex cases where
// elastic trivia and user trivia are mixed (hybrid case) and we want to preserve some part of user coding style
// but not others can be dealt with here.
// method has no statement in them. so basically two trivia list now pointing to same thing. "{" and "}"
if (method.Body != null)
{
if (tokenPair.PreviousToken == method.Body.OpenBraceToken &&
tokenPair.NextToken == method.Body.CloseBraceToken)
{
return((location == TriviaLocation.AfterBeginningOfSpan)
? SpecializedCollections.SingletonEnumerable(SyntaxFactory.ElasticMarker)
: SpecializedCollections.EmptyEnumerable <SyntaxTrivia>());
}
}
else
{
if (tokenPair.PreviousToken == method.ExpressionBody.ArrowToken &&
tokenPair.NextToken.GetPreviousToken() == method.EosToken)
{
return((location == TriviaLocation.AfterBeginningOfSpan)
? SpecializedCollections.SingletonEnumerable(SyntaxFactory.ElasticMarker)
: SpecializedCollections.EmptyEnumerable <SyntaxTrivia>());
}
}
var previousTriviaPair = triviaMap.ContainsKey(tokenPair.PreviousToken) ? triviaMap[tokenPair.PreviousToken] : default;
var nextTriviaPair = triviaMap.ContainsKey(tokenPair.NextToken) ? triviaMap[tokenPair.NextToken] : default;
var trailingTrivia = previousTriviaPair.TrailingTrivia ?? SpecializedCollections.EmptyEnumerable <SyntaxTrivia>();
var leadingTrivia = nextTriviaPair.LeadingTrivia ?? SpecializedCollections.EmptyEnumerable <SyntaxTrivia>();
var list = trailingTrivia.Concat(leadingTrivia);
switch (location)
{
case TriviaLocation.BeforeBeginningOfSpan:
return(FilterBeforeBeginningOfSpan(tokenPair, list));
case TriviaLocation.AfterEndOfSpan:
return(FilterTriviaList(list.Concat(tokenPair.NextToken.LeadingTrivia)));
case TriviaLocation.AfterBeginningOfSpan:
return(FilterTriviaList(AppendTrailingTrivia(tokenPair).Concat(list).Concat(tokenPair.NextToken.LeadingTrivia)));
case TriviaLocation.BeforeEndOfSpan:
return(FilterTriviaList(tokenPair.PreviousToken.TrailingTrivia.Concat(list).Concat(tokenPair.NextToken.LeadingTrivia)));
}
return(Contract.FailWithReturn <IEnumerable <SyntaxTrivia> >("Shouldn't reach here"));
}
private IEnumerable <SyntaxTrivia> AppendTrailingTrivia(PreviousNextTokenPair tokenPair)
{
if (tokenPair.PreviousToken.RawKind == (int)SyntaxKind.OpenBraceToken ||
tokenPair.PreviousToken.RawKind == (int)SyntaxKind.SemicolonToken)
{
return(tokenPair.PreviousToken.TrailingTrivia);
}
return(SpecializedCollections.EmptyEnumerable <SyntaxTrivia>());
}
private IEnumerable <SyntaxTrivia> FilterBeforeBeginningOfSpan(PreviousNextTokenPair tokenPair, IEnumerable <SyntaxTrivia> list)
{
var allList = FilterTriviaList(tokenPair.PreviousToken.TrailingTrivia.Concat(list).Concat(AppendLeadingTrivia(tokenPair)));
if (tokenPair.PreviousToken.RawKind == (int)SyntaxKind.OpenBraceToken)
{
return(RemoveBlankLines(allList));
}
return(allList);
}
