private InterpolationSyntax ParseInterpolation(string text, Lexer.Interpolation interpolation, bool isVerbatim)
{
SyntaxToken openBraceToken;
ExpressionSyntax expression;
InterpolationAlignmentClauseSyntax alignment = null;
InterpolationFormatClauseSyntax format = null;
var closeBraceToken = interpolation.CloseBraceMissing
? SyntaxFactory.MissingToken(SyntaxKind.CloseBraceToken)
: SyntaxFactory.Token(SyntaxKind.CloseBraceToken);
var parsedText = Substring(text, interpolation.OpenBracePosition, interpolation.HasColon ? interpolation.ColonPosition - 1 : interpolation.CloseBracePosition - 1);
using (var tempLexer = new Lexer(Text.SourceText.From(parsedText), this.Options, allowPreprocessorDirectives: false, interpolationFollowedByColon: interpolation.HasColon))
{
// TODO: some of the trivia in the interpolation maybe should be trailing trivia of the openBraceToken
using (var tempParser = new LanguageParser(tempLexer, null, null))
{
SyntaxToken commaToken = null;
ExpressionSyntax alignmentExpression = null;
tempParser.ParseInterpolationStart(out openBraceToken, out expression, out commaToken, out alignmentExpression);
if (alignmentExpression != null)
{
alignment = SyntaxFactory.InterpolationAlignmentClause(commaToken, alignmentExpression);
}
var extraTrivia = tempParser.CurrentToken.GetLeadingTrivia();
if (interpolation.HasColon)
{
var colonToken = SyntaxFactory.Token(SyntaxKind.ColonToken).TokenWithLeadingTrivia(extraTrivia);
var formatText = Substring(text, interpolation.ColonPosition + 1, interpolation.FormatEndPosition);
var formatString = MakeStringToken(formatText, formatText, isVerbatim, SyntaxKind.InterpolatedStringTextToken);
format = SyntaxFactory.InterpolationFormatClause(colonToken, formatString);
}
else
{
// Move the leading trivia from the insertion's EOF token to the following token.
closeBraceToken = closeBraceToken.TokenWithLeadingTrivia(extraTrivia);
}
}
}
var result = SyntaxFactory.Interpolation(openBraceToken, expression, alignment, format, closeBraceToken);
Debug.Assert(Substring(text, interpolation.OpenBracePosition, interpolation.LastPosition) == result.ToFullString()); // yield from text equals yield from node
return(result);
}