internal SnapshotSpan?GetExpressionAtPointWorker(SnapshotSpan span, GetExpressionOptions options)
{
// First do some very quick tokenization to save a full analysis
if (!IsPossibleExpressionAtPoint(span.Start))
{
return(null);
}
if (span.End.GetContainingLine() != span.Start.GetContainingLine() &&
!IsPossibleExpressionAtPoint(span.End))
{
return(null);
}
var sourceSpan = new SnapshotSpanSourceCodeReader(
new SnapshotSpan(span.Snapshot, 0, span.End.Position)
);
PythonAst ast;
using (var parser = Parser.CreateParser(sourceSpan, LanguageVersion)) {
ast = parser.ParseFile();
}
var finder = new ExpressionFinder(ast, options);
var actualExpr = finder.GetExpressionSpan(span.ToSourceSpan());
return(actualExpr?.ToSnapshotSpan(span.Snapshot));
}
