bool TryRemoveTransparentIdentifier(QueryExpression query, QueryFromClause fromClause, QueryExpression innerQuery, Dictionary <string, object> letClauses)
{
if (!IsTransparentIdentifier(fromClause.Identifier))
{
return(false);
}
QuerySelectClause selectClause = innerQuery.Clauses.Last() as QuerySelectClause;
Match match = selectTransparentIdentifierPattern.Match(selectClause);
if (!match.Success)
{
return(false);
}
// from * in (from x in ... select new { members of anonymous type }) ...
// =>
// from x in ... { let x = ... } ...
fromClause.Remove();
selectClause.Remove();
// Move clauses from innerQuery to query
QueryClause insertionPos = null;
foreach (var clause in innerQuery.Clauses)
{
query.Clauses.InsertAfter(insertionPos, insertionPos = clause.Detach());
}
foreach (var expr in match.Get <Expression>("expr"))
{
switch (expr)
{
case IdentifierExpression identifier:
// nothing to add
continue;
case NamedExpression namedExpression:
if (namedExpression.Expression is IdentifierExpression identifierExpression && namedExpression.Name == identifierExpression.Identifier)
{
letClauses[namedExpression.Name] = identifierExpression.Annotation <ILVariableResolveResult>();
continue;
}
QueryLetClause letClause = new QueryLetClause {
Identifier = namedExpression.Name, Expression = namedExpression.Expression.Detach()
};
var annotation = new LetIdentifierAnnotation();
letClause.AddAnnotation(annotation);
letClauses[namedExpression.Name] = annotation;
query.Clauses.InsertAfter(insertionPos, letClause);
break;
}
}
return(true);
}
public ApplyAnnotationVisitor(LetIdentifierAnnotation annotation, string identifier)
{
this.annotation = annotation;
this.identifier = identifier;
}