private SyntaxTree WithChanges(SourceText newText, IReadOnlyList <TextChangeRange> changes)
{
if (changes == null)
{
throw new ArgumentNullException(nameof(changes));
}
var oldTree = this;
// if changes is entire text do a full reparse
if (changes.Count == 1 && changes[0].Span == new TextSpan(0, this.Length) && changes[0].NewLength == newText.Length)
{
// parser will do a full parse if we give it no changes
changes = null;
oldTree = null;
}
using (var lexer = new InternalSyntax.Lexer(newText, this.Options))
using (var parser = new InternalSyntax.LanguageParser(lexer, oldTree?.GetRoot(), changes))
{
var compilationUnit = (CompilationUnitSyntax)parser.ParseCompilationUnit().CreateRed();
var tree = new ParsedSyntaxTree(newText, newText.Encoding, newText.ChecksumAlgorithm, this.FilePath, this.Options, compilationUnit, parser.Directives);
tree.VerifySource(changes);
return(tree);
}
}
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);
}
/// <summary>
/// Produces a syntax tree by parsing the source text.
/// </summary>
public static SyntaxTree ParseText(
SourceText text,
CSharpParseOptions options = null,
string path = "",
CancellationToken cancellationToken = default(CancellationToken))
{
if (text == null)
{
throw new ArgumentNullException(nameof(text));
}
options = options ?? CSharpParseOptions.Default;
using (var lexer = new InternalSyntax.Lexer(text, options))
{
using (var parser = new InternalSyntax.LanguageParser(lexer, oldTree: null, changes: null, cancellationToken: cancellationToken))
{
var compilationUnit = (CompilationUnitSyntax)parser.ParseCompilationUnit().CreateRed();
var tree = new ParsedSyntaxTree(text, text.Encoding, text.ChecksumAlgorithm, path, options, compilationUnit, parser.Directives);
tree.VerifySource();
return(tree);
}
}
}
