bool TryRemoveTransparentIdentifier(QueryExpression query, QueryFromClause fromClause, QueryExpression innerQuery)
{
if (!IsTransparentIdentifier(fromClause.Identifier))
{
return(false);
}
Match match = selectTransparentIdentifierPattern.Match(innerQuery.Clauses.Last());
if (!match.Success)
{
return(false);
}
QuerySelectClause selectClause = (QuerySelectClause)innerQuery.Clauses.Last();
NamedArgumentExpression nae1 = match.Get <NamedArgumentExpression>("nae1").Single();
NamedArgumentExpression nae2 = match.Get <NamedArgumentExpression>("nae2").Single();
if (nae1.Identifier != ((IdentifierExpression)nae1.Expression).Identifier)
{
return(false);
}
IdentifierExpression nae2IdentExpr = nae2.Expression as IdentifierExpression;
if (nae2IdentExpr != null && nae2.Identifier == nae2IdentExpr.Identifier)
{
// from * in (from x in ... select new { x = x, y = y }) ...
// =>
// from x in ... ...
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());
}
}
else
{
// from * in (from x in ... select new { x = x, y = expr }) ...
// =>
// from x in ... let y = expr ...
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());
}
query.Clauses.InsertAfter(insertionPos, new QueryLetClause {
Identifier = nae2.Identifier, Expression = nae2.Expression.Detach()
});
}
return(true);
}
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);
}
bool TryRemoveTransparentIdentifier(QueryExpression query, QueryFromClause fromClause, QueryExpression innerQuery)
{
if (!IsTransparentIdentifier(fromClause.Identifier))
{
return(false);
}
Match match = selectTransparentIdentifierPattern.Match(innerQuery.Clauses.Last());
if (!match.Success)
{
return(false);
}
QuerySelectClause selectClause = (QuerySelectClause)innerQuery.Clauses.Last();
NamedExpression nae1 = match.Get <NamedExpression>("nae1").SingleOrDefault();
NamedExpression nae2 = match.Get <NamedExpression>("nae2").SingleOrDefault();
if (nae1 != null && nae1.Name != ((IdentifierExpression)nae1.Expression).Identifier)
{
return(false);
}
Expression nae2Expr = match.Get <Expression>("nae2Expr").Single();
IdentifierExpression nae2IdentExpr = nae2Expr as IdentifierExpression;
if (nae2IdentExpr != null && (nae2 == null || nae2.Name == nae2IdentExpr.Identifier))
{
// from * in (from x in ... select new { x = x, y = y }) ...
// =>
// from x in ... ...
fromClause.Remove();
selectClause.Remove();
// Move clauses from innerQuery to query
QueryClause insertionPos = null;
foreach (var clause in innerQuery.Clauses)
{
query.Clauses.InsertAfter(insertionPos, insertionPos = Detach(clause));
}
}
else
{
// from * in (from x in ... select new { x = x, y = expr }) ...
// =>
// from x in ... let y = expr ...
fromClause.Remove();
selectClause.Remove();
// Move clauses from innerQuery to query
QueryClause insertionPos = null;
foreach (var clause in innerQuery.Clauses)
{
query.Clauses.InsertAfter(insertionPos, insertionPos = Detach(clause));
}
string ident;
if (nae2 != null)
{
ident = nae2.Name;
}
else if (nae2Expr is MemberReferenceExpression)
{
ident = ((MemberReferenceExpression)nae2Expr).MemberName;
}
else
{
throw new InvalidOperationException("Could not infer name from initializer in AnonymousTypeCreateExpression");
}
query.Clauses.InsertAfter(insertionPos, new QueryLetClause {
Identifier = ident, Expression = Detach(nae2Expr)
});
}
return(true);
}