private BoundExpression BindQueryInternal2(QueryTranslationState state, BindingDiagnosticBag diagnostics)
{
// we continue reducing the query until it is reduced away.
while (true)
{
if (state.clauses.IsEmpty())
{
if (state.selectOrGroup == null)
{
return(state.fromExpression); // already reduced away
}
if (IsDegenerateQuery(state))
{
// A query expression of the form
// from x in e select x
// is translated into
// ( e )
var result = state.fromExpression;
// ignore missing or malformed Select method
BoundExpression?unoptimized = FinalTranslation(state, BindingDiagnosticBag.Discarded);
if (unoptimized.HasAnyErrors && !result.HasAnyErrors)
{
unoptimized = null;
}
return(MakeQueryClause(state.selectOrGroup, result, unoptimizedForm: unoptimized));
}
return(FinalTranslation(state, diagnostics));
}
ReduceQuery(state, diagnostics);
}
}
private void ReduceQuery(QueryTranslationState state, DiagnosticBag diagnostics)
{
var topClause = state.clauses.Pop();
switch (topClause.Kind())
{
case SyntaxKind.WhereClause:
ReduceWhere((WhereClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.JoinClause:
ReduceJoin((JoinClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.OrderByClause:
ReduceOrderBy((OrderByClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.FromClause:
ReduceFrom((FromClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.LetClause:
ReduceLet((LetClauseSyntax)topClause, state, diagnostics);
break;
default:
throw ExceptionUtilities.UnexpectedValue(topClause.Kind());
}
}
private void ReduceOrderBy(OrderByClauseSyntax orderby, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with an orderby clause
// from x in e
// orderby k1 , k2 , ... , kn
// ...
// is translated into
// from x in ( e ) .
// OrderBy ( x => k1 ) .
// ThenBy ( x => k2 ) .
// ... .
// ThenBy ( x => kn )
// ...
// If an ordering clause specifies a descending direction indicator,
// an invocation of OrderByDescending or ThenByDescending is produced instead.
bool first = true;
foreach (var ordering in orderby.Orderings)
{
string methodName = (first ? "OrderBy" : "ThenBy") + (ordering.IsKind(SyntaxKind.DescendingOrdering) ? "Descending" : "");
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, ordering.Expression);
var invocation = MakeQueryInvocation(ordering, state.fromExpression, methodName, lambda, diagnostics);
state.fromExpression = MakeQueryClause(ordering, invocation, queryInvocation: invocation);
first = false;
}
state.fromExpression = MakeQueryClause(orderby, state.fromExpression);
}
private UnboundLambda MakePairLambda(CSharpSyntaxNode node, QueryTranslationState state, RangeVariableSymbol x1, RangeVariableSymbol x2)
{
Debug.Assert(LambdaUtilities.IsQueryPairLambda(node));
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var x1Expression = new BoundParameter(node, lambdaSymbol.Parameters[0])
{
WasCompilerGenerated = true
};
var x2Expression = new BoundParameter(node, lambdaSymbol.Parameters[1])
{
WasCompilerGenerated = true
};
var construction = MakePair(node, x1.Name, x1Expression, x2.Name, x2Expression, state, d);
return(lambdaBodyBinder.CreateBlockFromExpression(node, ImmutableArray <LocalSymbol> .Empty, RefKind.None, construction, null, d));
};
var result = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, x2), node, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x1.Name);
var x2m = state.allRangeVariables[x2];
x2m[x2m.Count - 1] = x2.Name;
return(result);
}
private BoundExpression BindQueryInternal1(QueryTranslationState state, DiagnosticBag diagnostics)
{
// If the query is a degenerate one the form "from x in e select x", but in source,
// then we go ahead and generate the select anyway. We do this by skipping BindQueryInternal2,
// whose job it is to (reduce away the whole query and) optimize away degenerate queries.
return(IsDegenerateQuery(state) ? FinalTranslation(state, diagnostics) : BindQueryInternal2(state, diagnostics));
}
private BoundExpression BindQueryInternal1(QueryTranslationState state, DiagnosticBag diagnostics)
{
// If the query is a degenerate one the form "from x in e select x", but in source,
// then we go ahead and generate the select anyway. We do this by skipping BindQueryInternal2,
// whose job it is to (reduce away the whole query and) optimize away degenerate queries.
return IsDegenerateQuery(state) ? FinalTranslation(state, diagnostics) : BindQueryInternal2(state, diagnostics);
}
private void ReduceLet(LetClauseSyntax let, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a let clause
// from x in e
// let y = f
// ...
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// ...
var x = state.rangeVariable;
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaSymbol.Parameters[0])
{
WasCompilerGenerated = true
};
lambdaBodyBinder = lambdaBodyBinder.GetBinder(let.Expression);
Debug.Assert(lambdaBodyBinder != null);
var yExpression = lambdaBodyBinder.BindValue(let.Expression, d, BindValueKind.RValue);
SourceLocation errorLocation = new SourceLocation(let.SyntaxTree, new TextSpan(let.Identifier.SpanStart, let.Expression.Span.End - let.Identifier.SpanStart));
if (!yExpression.HasAnyErrors && !yExpression.HasExpressionType())
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Display);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create(yExpression), CreateErrorType());
}
else if (!yExpression.HasAnyErrors && yExpression.Type.SpecialType == SpecialType.System_Void)
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Type);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create(yExpression), yExpression.Type);
}
var construction = MakePair(let, x.Name, xExpression, let.Identifier.ValueText, yExpression, state, d);
// The bound block represents a closure scope for transparent identifiers captured in the let clause.
// Such closures shall be associated with the lambda body expression.
return(lambdaBodyBinder.CreateLambdaBlockForQueryClause(let.Expression, construction, d));
};
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x), let.Expression, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x.Name);
var y = state.AddRangeVariable(this, let.Identifier, diagnostics);
state.allRangeVariables[y].Add(let.Identifier.ValueText);
var invocation = MakeQueryInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.fromExpression = MakeQueryClause(let, invocation, y, invocation);
}
internal BoundExpression BindQuery(QueryExpressionSyntax node, DiagnosticBag diagnostics)
{
var fromClause = node.FromClause;
var boundFromExpression = BindLeftOfPotentialColorColorMemberAccess(fromClause.Expression, diagnostics);
QueryTranslationState state = new QueryTranslationState();
state.fromExpression = MakeMemberAccessValue(boundFromExpression, diagnostics);
var x = state.rangeVariable = state.AddRangeVariable(this, fromClause.Identifier, diagnostics);
for (int i = node.Body.Clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(node.Body.Clauses[i]);
}
state.selectOrGroup = node.Body.SelectOrGroup;
// A from clause that explicitly specifies a range variable type
// from T x in e
// is translated into
// from x in ( e ) . Cast < T > ( )
BoundExpression cast = null;
if (fromClause.Type != null)
{
var typeRestriction = BindTypeArgument(fromClause.Type, diagnostics);
cast = MakeQueryInvocation(fromClause, state.fromExpression, "Cast", fromClause.Type, typeRestriction, diagnostics);
state.fromExpression = cast;
}
state.fromExpression = MakeQueryClause(fromClause, state.fromExpression, x, castInvocation: cast);
BoundExpression result = BindQueryInternal1(state, diagnostics);
for (QueryContinuationSyntax continuation = node.Body.Continuation; continuation != null; continuation = continuation.Body.Continuation)
{
// A query expression with a continuation
// from ... into x ...
// is translated into
// from x in ( from ... ) ...
state.Clear();
state.fromExpression = result;
x = state.rangeVariable = state.AddRangeVariable(this, continuation.Identifier, diagnostics);
Debug.Assert(state.clauses.IsEmpty());
var clauses = continuation.Body.Clauses;
for (int i = clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(clauses[i]);
}
state.selectOrGroup = continuation.Body.SelectOrGroup;
result = BindQueryInternal1(state, diagnostics);
result = MakeQueryClause(continuation.Body, result, x);
result = MakeQueryClause(continuation, result, x);
}
state.Free();
return(MakeQueryClause(node, result));
}
void ReduceFrom(FromClauseSyntax from, QueryTranslationState state, DiagnosticBag diagnostics)
{
var x1 = state.rangeVariable;
TypeSymbol castType = from.Type == null ? null : BindTypeArgument(from.Type, diagnostics);
BoundExpression lambda1 = MakeQueryUnboundLambda(state.RangeVariableMap(), x1, from.Expression, from.Type, castType);
var x2 = state.AddRangeVariable(this, from.Identifier, diagnostics);
if (state.clauses.IsEmpty() && state.selectOrGroup.Kind == SyntaxKind.SelectClause)
{
// A query expression with a second from clause followed by a select clause
// from x1 in e1
// from x2 in e2
// select v
// is translated into
// ( e1 ) . SelectMany( x1 => e2 , ( x1 , x2 ) => v )
var select = state.selectOrGroup as SelectClauseSyntax;
BoundExpression lambda2 = MakeQueryUnboundLambda(state.RangeVariableMap(), Args(x1, x2), select.Expression);
var invocation = MakeQueryInvocation(from, state.fromExpression, "SelectMany", Args(lambda1, lambda2), diagnostics);
BoundExpression castInvocation = (object)castType != null?ExtractCastInvocation(invocation) : null;
var arguments = invocation.Arguments.ToArray();
// Adjust the second-to-last parameter to be a query clause. (if it was an extension method, an extra parameter was added)
arguments[arguments.Length - 2] = MakeQueryClause(from, arguments[arguments.Length - 2], x2, invocation, castInvocation);
invocation = invocation.Update(invocation.ReceiverOpt, invocation.Method, Args(arguments));
state.Clear();
state.fromExpression = MakeQueryClause(from, invocation, definedSymbol: x2, queryInvocation: invocation);
state.fromExpression = MakeQueryClause(select, state.fromExpression);
}
else
{
// A query expression with a second from clause followed by something other than a select clause:
// from x1 in e1
// from x2 in e2
// ...
// is translated into
// from * in ( e1 ) . SelectMany( x1 => e2 , ( x1 , x2 ) => new { x1 , x2 } )
// ...
// We use a slightly different translation strategy. We produce
// from * in ( e ) . SelectMany ( x1 => e2, ( x1 , x2 ) => new Pair<X1,X2>(x1, x2) )
// Where X1 is the type of x1, and X2 is the type of x2.
// Subsequently, x1 (or members of x1, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and x2 is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
var lambda2 = MakePairLambda(from, state, x1, x2);
var invocation = MakeQueryInvocation(from, state.fromExpression, "SelectMany", Args(lambda1, lambda2), diagnostics);
BoundExpression castInvocation = (object)castType != null?ExtractCastInvocation(invocation) : null;
state.fromExpression = MakeQueryClause(from, invocation, x2, invocation, castInvocation);
}
}
private void ReduceWhere(WhereClauseSyntax where, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a where clause
// from x in e
// where f
// ...
// is translated into
// from x in ( e ) . Where ( x => f )
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, where.Condition);
var invocation = MakeQueryInvocation(where, state.fromExpression, "Where", lambda, diagnostics);
state.fromExpression = MakeQueryClause(where, invocation, queryInvocation: invocation);
}
private static bool IsDegenerateQuery(QueryTranslationState state)
{
if (!state.clauses.IsEmpty())
{
return(false);
}
// A degenerate query is of the form "from x in e select x".
var select = state.selectOrGroup as SelectClauseSyntax;
if (select == null)
{
return(false);
}
var name = select.Expression as IdentifierNameSyntax;
return(name != null && state.rangeVariable.Name == name.Identifier.ValueText);
}
BoundExpression BindQueryInternal2(QueryTranslationState state, DiagnosticBag diagnostics)
{
// we continue reducing the query until it is reduced away.
while (true)
{
if (state.clauses.IsEmpty())
{
if (IsDegenerateQuery(state))
{
// A query expression of the form
// from x in e select x
// is translated into
// ( e )
return(state.fromExpression);
}
return(FinalTranslation(state, diagnostics));
}
ReduceQuery(state, diagnostics);
}
}
private bool IsDegenerateQuery(QueryTranslationState state)
{
if (!state.clauses.IsEmpty())
{
return(false);
}
// Some translations complete the whole query, which they flag by setting selectOrGroup to null.
if (state.selectOrGroup == null)
{
return(true);
}
// A degenerate query is of the form "from x in e select x".
var select = state.selectOrGroup as SelectClauseSyntax;
if (select == null)
{
return(false);
}
var identifier = select.Expression as IdentifierNameSyntax;
return(identifier != null && state.queryVariable.Name == identifier.Identifier.ValueText);
}
UnboundLambda MakePairLambda(CSharpSyntaxNode node, QueryTranslationState state, RangeVariableSymbol x1, RangeVariableSymbol x2)
{
LambdaBodyResolver resolver = (LambdaSymbol lambdaSymbol, ref Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var x1Expression = new BoundParameter(node, lambdaSymbol.Parameters[0])
{
WasCompilerGenerated = true
};
var x2Expression = new BoundParameter(node, lambdaSymbol.Parameters[1])
{
WasCompilerGenerated = true
};
var construction = MakePair(node, x1.Name, x1Expression, x2.Name, x2Expression, state, d);
return(lambdaBodyBinder.CreateBlockFromExpression(ImmutableArray <LocalSymbol> .Empty, construction, node, d));
};
var result = MakeQueryUnboundLambda(state.RangeVariableMap(), Args(x1, x2), node, resolver);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x1.Name);
var x2m = state.allRangeVariables[x2];
x2m[x2m.Count - 1] = x2.Name;
return(result);
}
private void ReduceWhere(WhereClauseSyntax where, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a where clause
// from x in e
// where f
// ...
// is translated into
// from x in ( e ) . Where ( x => f )
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, where.Condition);
var invocation = MakeQueryInvocation(where, state.fromExpression, "Where", lambda, diagnostics);
state.fromExpression = MakeQueryClause(where, invocation, queryInvocation: invocation);
}
private void ReduceJoin(JoinClauseSyntax join, QueryTranslationState state, DiagnosticBag diagnostics)
{
var inExpression = BindValue(join.InExpression, diagnostics, BindValueKind.RValue);
// If the from expression is of the type dynamic we can't infer the types for any lambdas that occur in the query.
// Only if there are none we could bind the query but we report an error regardless since such queries are not useful.
if (inExpression.HasDynamicType())
{
diagnostics.Add(ErrorCode.ERR_BadDynamicQuery, join.InExpression.Location);
inExpression = BadExpression(join.InExpression, inExpression);
}
BoundExpression castInvocation = null;
if (join.Type != null)
{
// A join clause that explicitly specifies a range variable type
// join T x in e on k1 equals k2
// is translated into
// join x in ( e ) . Cast < T > ( ) on k1 equals k2
var castType = BindTypeArgument(join.Type, diagnostics);
castInvocation = MakeQueryInvocation(join, inExpression, "Cast", join.Type, castType, diagnostics);
inExpression = castInvocation;
}
var outerKeySelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, join.LeftExpression);
var x1 = state.rangeVariable;
var x2 = state.AddRangeVariable(this, join.Identifier, diagnostics);
var innerKeySelectorLambda = MakeQueryUnboundLambda(QueryTranslationState.RangeVariableMap(x2), x2, join.RightExpression);
if (state.clauses.IsEmpty() && state.selectOrGroup.Kind() == SyntaxKind.SelectClause)
{
var select = state.selectOrGroup as SelectClauseSyntax;
BoundCall invocation;
if (join.Into == null)
{
// A query expression with a join clause without an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2
// select v
// is translated into
// ( e1 ) . Join( e2 , x1 => k1 , x2 => k2 , ( x1 , x2 ) => v )
var resultSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, x2), select.Expression);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"Join",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
}
else
{
// A query expression with a join clause with an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2 into g
// select v
// is translated into
// ( e1 ) . GroupJoin( e2 , x1 => k1 , x2 => k2 , ( x1 , g ) => v )
state.allRangeVariables[x2].Free();
state.allRangeVariables.Remove(x2);
var g = state.AddRangeVariable(this, join.Into.Identifier, diagnostics);
var resultSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, g), select.Expression);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"GroupJoin",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
// record the into clause in the bound tree
var arguments = invocation.Arguments;
arguments = arguments.SetItem(arguments.Length - 1, MakeQueryClause(join.Into, arguments[arguments.Length - 1], g));
invocation = invocation.Update(invocation.ReceiverOpt, invocation.Method, arguments);
}
state.Clear(); // this completes the whole query
state.fromExpression = MakeQueryClause(join, invocation, x2, invocation, castInvocation);
state.fromExpression = MakeQueryClause(select, state.fromExpression);
}
else
{
BoundCall invocation;
if (join.Into == null)
{
// A query expression with a join clause without an into followed by something other than a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2
// ...
// is translated into
// from * in ( e1 ) . Join(
// e2 , x1 => k1 , x2 => k2 , ( x1 , x2 ) => new { x1 , x2 })
// ...
var resultSelectorLambda = MakePairLambda(join, state, x1, x2);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"Join",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
}
else
{
// A query expression with a join clause with an into followed by something other than a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2 into g
// ...
// is translated into
// from * in ( e1 ) . GroupJoin(
// e2 , x1 => k1 , x2 => k2 , ( x1 , g ) => new { x1 , g })
// ...
state.allRangeVariables[x2].Free();
state.allRangeVariables.Remove(x2);
var g = state.AddRangeVariable(this, join.Into.Identifier, diagnostics);
var resultSelectorLambda = MakePairLambda(join, state, x1, g);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"GroupJoin",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
var arguments = invocation.Arguments;
arguments = arguments.SetItem(arguments.Length - 1, MakeQueryClause(join.Into, arguments[arguments.Length - 1], g));
invocation = invocation.Update(invocation.ReceiverOpt, invocation.Method, arguments);
}
state.fromExpression = MakeQueryClause(join, invocation, x2, invocation, castInvocation);
}
}
internal BoundExpression BindQuery(QueryExpressionSyntax node, DiagnosticBag diagnostics)
{
var fromClause = node.FromClause;
var boundFromExpression = BindLeftOfPotentialColorColorMemberAccess(fromClause.Expression, diagnostics);
// If the from expression is of the type dynamic we can't infer the types for any lambdas that occur in the query.
// Only if there are none we could bind the query but we report an error regardless since such queries are not useful.
if (boundFromExpression.HasDynamicType())
{
diagnostics.Add(ErrorCode.ERR_BadDynamicQuery, fromClause.Expression.Location);
boundFromExpression = BadExpression(fromClause.Expression, boundFromExpression);
}
QueryTranslationState state = new QueryTranslationState();
state.fromExpression = MakeMemberAccessValue(boundFromExpression, diagnostics);
var x = state.rangeVariable = state.AddRangeVariable(this, fromClause.Identifier, diagnostics);
for (int i = node.Body.Clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(node.Body.Clauses[i]);
}
state.selectOrGroup = node.Body.SelectOrGroup;
// A from clause that explicitly specifies a range variable type
// from T x in e
// is translated into
// from x in ( e ) . Cast < T > ( )
BoundExpression cast = null;
if (fromClause.Type != null)
{
var typeRestriction = BindTypeArgument(fromClause.Type, diagnostics);
cast = MakeQueryInvocation(fromClause, state.fromExpression, "Cast", fromClause.Type, typeRestriction, diagnostics);
state.fromExpression = cast;
}
state.fromExpression = MakeQueryClause(fromClause, state.fromExpression, x, castInvocation: cast);
BoundExpression result = BindQueryInternal1(state, diagnostics);
for (QueryContinuationSyntax continuation = node.Body.Continuation; continuation != null; continuation = continuation.Body.Continuation)
{
// A query expression with a continuation
// from ... into x ...
// is translated into
// from x in ( from ... ) ...
state.Clear();
state.fromExpression = result;
x = state.rangeVariable = state.AddRangeVariable(this, continuation.Identifier, diagnostics);
Debug.Assert(state.clauses.IsEmpty());
var clauses = continuation.Body.Clauses;
for (int i = clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(clauses[i]);
}
state.selectOrGroup = continuation.Body.SelectOrGroup;
result = BindQueryInternal1(state, diagnostics);
result = MakeQueryClause(continuation.Body, result, x);
result = MakeQueryClause(continuation, result, x);
}
state.Free();
return(MakeQueryClause(node, result));
}
private void ReduceJoin(JoinClauseSyntax join, QueryTranslationState state, DiagnosticBag diagnostics)
{
var inExpression = BindValue(join.InExpression, diagnostics, BindValueKind.RValue);
// If the from expression is of the type dynamic we can't infer the types for any lambdas that occur in the query.
// Only if there are none we could bind the query but we report an error regardless since such queries are not useful.
if (inExpression.HasDynamicType())
{
diagnostics.Add(ErrorCode.ERR_BadDynamicQuery, join.InExpression.Location);
inExpression = BadExpression(join.InExpression, inExpression);
}
BoundExpression castInvocation = null;
if (join.Type != null)
{
// A join clause that explicitly specifies a range variable type
// join T x in e on k1 equals k2
// is translated into
// join x in ( e ) . Cast < T > ( ) on k1 equals k2
var castType = BindTypeArgument(join.Type, diagnostics);
castInvocation = MakeQueryInvocation(join, inExpression, "Cast", join.Type, castType, diagnostics);
inExpression = castInvocation;
}
var outerKeySelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, join.LeftExpression);
var x1 = state.rangeVariable;
var x2 = state.AddRangeVariable(this, join.Identifier, diagnostics);
var innerKeySelectorLambda = MakeQueryUnboundLambda(QueryTranslationState.RangeVariableMap(x2), x2, join.RightExpression);
if (state.clauses.IsEmpty() && state.selectOrGroup.Kind() == SyntaxKind.SelectClause)
{
var select = state.selectOrGroup as SelectClauseSyntax;
BoundCall invocation;
if (join.Into == null)
{
// A query expression with a join clause without an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2
// select v
// is translated into
// ( e1 ) . Join( e2 , x1 => k1 , x2 => k2 , ( x1 , x2 ) => v )
var resultSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, x2), select.Expression);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"Join",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
}
else
{
// A query expression with a join clause with an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2 into g
// select v
// is translated into
// ( e1 ) . GroupJoin( e2 , x1 => k1 , x2 => k2 , ( x1 , g ) => v )
state.allRangeVariables[x2].Free();
state.allRangeVariables.Remove(x2);
var g = state.AddRangeVariable(this, join.Into.Identifier, diagnostics);
var resultSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, g), select.Expression);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"GroupJoin",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
// record the into clause in the bound tree
var arguments = invocation.Arguments;
arguments = arguments.SetItem(arguments.Length - 1, MakeQueryClause(join.Into, arguments[arguments.Length - 1], g));
invocation = invocation.Update(invocation.ReceiverOpt, invocation.Method, arguments);
}
state.Clear(); // this completes the whole query
state.fromExpression = MakeQueryClause(join, invocation, x2, invocation, castInvocation);
state.fromExpression = MakeQueryClause(select, state.fromExpression);
}
else
{
BoundCall invocation;
if (join.Into == null)
{
// A query expression with a join clause without an into followed by something other than a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2
// ...
// is translated into
// from * in ( e1 ) . Join(
// e2 , x1 => k1 , x2 => k2 , ( x1 , x2 ) => new { x1 , x2 })
// ...
var resultSelectorLambda = MakePairLambda(join, state, x1, x2);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"Join",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
}
else
{
// A query expression with a join clause with an into followed by something other than a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2 into g
// ...
// is translated into
// from * in ( e1 ) . GroupJoin(
// e2 , x1 => k1 , x2 => k2 , ( x1 , g ) => new { x1 , g })
// ...
state.allRangeVariables[x2].Free();
state.allRangeVariables.Remove(x2);
var g = state.AddRangeVariable(this, join.Into.Identifier, diagnostics);
var resultSelectorLambda = MakePairLambda(join, state, x1, g);
invocation = MakeQueryInvocation(
join,
state.fromExpression,
"GroupJoin",
ImmutableArray.Create(inExpression, outerKeySelectorLambda, innerKeySelectorLambda, resultSelectorLambda),
diagnostics);
var arguments = invocation.Arguments;
arguments = arguments.SetItem(arguments.Length - 1, MakeQueryClause(join.Into, arguments[arguments.Length - 1], g));
invocation = invocation.Update(invocation.ReceiverOpt, invocation.Method, arguments);
}
state.fromExpression = MakeQueryClause(join, invocation, x2, invocation, castInvocation);
}
}
private BoundExpression MakePair(CSharpSyntaxNode node, string field1Name, BoundExpression field1Value, string field2Name, BoundExpression field2Value, QueryTranslationState state, DiagnosticBag diagnostics)
{
if (field1Name == field2Name)
{
// we will generate a diagnostic elsewhere
field2Name = state.TransparentRangeVariableName();
field2Value = new BoundBadExpression(field2Value.Syntax, LookupResultKind.Empty, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(field2Value), field2Value.Type, true);
}
AnonymousTypeDescriptor typeDescriptor = new AnonymousTypeDescriptor(
ImmutableArray.Create<AnonymousTypeField>(
new AnonymousTypeField(field1Name, field1Value.Syntax.Location, TypeOrError(field1Value)),
new AnonymousTypeField(field2Name, field2Value.Syntax.Location, TypeOrError(field2Value))
),
node.Location
);
AnonymousTypeManager manager = this.Compilation.AnonymousTypeManager;
NamedTypeSymbol anonymousType = manager.ConstructAnonymousTypeSymbol(typeDescriptor);
return MakeConstruction(node, anonymousType, ImmutableArray.Create(field1Value, field2Value), diagnostics);
}
private BoundExpression FinalTranslation(QueryTranslationState state, DiagnosticBag diagnostics)
{
Debug.Assert(state.clauses.IsEmpty());
switch (state.selectOrGroup.Kind())
{
case SyntaxKind.SelectClause:
{
// A query expression of the form
// from x in e select v
// is translated into
// ( e ) . Select ( x => v )
var selectClause = (SelectClauseSyntax)state.selectOrGroup;
var x = state.rangeVariable;
var e = state.fromExpression;
var v = selectClause.Expression;
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), x, v);
var result = MakeQueryInvocation(state.selectOrGroup, e, "Select", lambda, diagnostics);
return(MakeQueryClause(selectClause, result, queryInvocation: result));
}
case SyntaxKind.GroupClause:
{
// A query expression of the form
// from x in e group v by k
// is translated into
// ( e ) . GroupBy ( x => k , x => v )
// except when v is the identifier x, the translation is
// ( e ) . GroupBy ( x => k )
var groupClause = (GroupClauseSyntax)state.selectOrGroup;
var x = state.rangeVariable;
var e = state.fromExpression;
var v = groupClause.GroupExpression;
var k = groupClause.ByExpression;
var vId = v as IdentifierNameSyntax;
BoundCall result;
var lambdaLeft = MakeQueryUnboundLambda(state.RangeVariableMap(), x, k);
// this is the unoptimized form (when v is not the identifier x)
var d = DiagnosticBag.GetInstance();
BoundExpression lambdaRight = MakeQueryUnboundLambda(state.RangeVariableMap(), x, v);
result = MakeQueryInvocation(state.selectOrGroup, e, "GroupBy", ImmutableArray.Create(lambdaLeft, lambdaRight), d);
// k and v appear reversed in the invocation, so we reorder their evaluation
result = ReverseLastTwoParameterOrder(result);
BoundExpression unoptimizedForm = null;
if (vId != null && vId.Identifier.ValueText == x.Name)
{
// The optimized form. We store the unoptimized form for analysis
unoptimizedForm = result;
result = MakeQueryInvocation(state.selectOrGroup, e, "GroupBy", lambdaLeft, diagnostics);
if (unoptimizedForm.HasAnyErrors && !result.HasAnyErrors)
{
unoptimizedForm = null;
}
}
else
{
diagnostics.AddRange(d);
}
d.Free();
return(MakeQueryClause(groupClause, result, queryInvocation: result, unoptimizedForm: unoptimizedForm));
}
default:
{
// there should have been a syntax error if we get here.
return(new BoundBadExpression(
state.selectOrGroup, LookupResultKind.OverloadResolutionFailure, ImmutableArray <Symbol> .Empty,
ImmutableArray.Create(state.fromExpression), state.fromExpression.Type));
}
}
}
private BoundExpression FinalTranslation(QueryTranslationState state, DiagnosticBag diagnostics)
{
Debug.Assert(state.clauses.IsEmpty());
switch (state.selectOrGroup.Kind())
{
case SyntaxKind.SelectClause:
{
// A query expression of the form
// from x in e select v
// is translated into
// ( e ) . Select ( x => v )
var selectClause = (SelectClauseSyntax)state.selectOrGroup;
var x = state.rangeVariable;
var e = state.fromExpression;
var v = selectClause.Expression;
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), x, v);
var result = MakeQueryInvocation(state.selectOrGroup, e, "Select", lambda, diagnostics);
return MakeQueryClause(selectClause, result, queryInvocation: result);
}
case SyntaxKind.GroupClause:
{
// A query expression of the form
// from x in e group v by k
// is translated into
// ( e ) . GroupBy ( x => k , x => v )
// except when v is the identifier x, the translation is
// ( e ) . GroupBy ( x => k )
var groupClause = (GroupClauseSyntax)state.selectOrGroup;
var x = state.rangeVariable;
var e = state.fromExpression;
var v = groupClause.GroupExpression;
var k = groupClause.ByExpression;
var vId = v as IdentifierNameSyntax;
BoundCall result;
var lambdaLeft = MakeQueryUnboundLambda(state.RangeVariableMap(), x, k);
// this is the unoptimized form (when v is not the identifier x)
var d = DiagnosticBag.GetInstance();
BoundExpression lambdaRight = MakeQueryUnboundLambda(state.RangeVariableMap(), x, v);
result = MakeQueryInvocation(state.selectOrGroup, e, "GroupBy", ImmutableArray.Create(lambdaLeft, lambdaRight), d);
// k and v appear reversed in the invocation, so we reorder their evaluation
result = ReverseLastTwoParameterOrder(result);
BoundExpression unoptimizedForm = null;
if (vId != null && vId.Identifier.ValueText == x.Name)
{
// The optimized form. We store the unoptimized form for analysis
unoptimizedForm = result;
result = MakeQueryInvocation(state.selectOrGroup, e, "GroupBy", lambdaLeft, diagnostics);
if (unoptimizedForm.HasAnyErrors && !result.HasAnyErrors) unoptimizedForm = null;
}
else
{
diagnostics.AddRange(d);
}
d.Free();
return MakeQueryClause(groupClause, result, queryInvocation: result, unoptimizedForm: unoptimizedForm);
}
default:
{
// there should have been a syntax error if we get here.
return new BoundBadExpression(
state.selectOrGroup, LookupResultKind.OverloadResolutionFailure, ImmutableArray<Symbol>.Empty,
ImmutableArray.Create<BoundNode>(state.fromExpression), state.fromExpression.Type);
}
}
}
private BoundExpression BindQueryInternal2(QueryTranslationState state, DiagnosticBag diagnostics)
{
// we continue reducing the query until it is reduced away.
while (true)
{
if (state.clauses.IsEmpty())
{
if (state.selectOrGroup == null)
{
return state.fromExpression; // already reduced away
}
if (IsDegenerateQuery(state))
{
// A query expression of the form
// from x in e select x
// is translated into
// ( e )
var result = state.fromExpression;
// ignore missing or malformed Select method
DiagnosticBag discarded = DiagnosticBag.GetInstance();
var unoptimized = FinalTranslation(state, discarded);
discarded.Free();
if (unoptimized.HasAnyErrors && !result.HasAnyErrors) unoptimized = null;
return MakeQueryClause(state.selectOrGroup, result, unoptimizedForm: unoptimized);
}
return FinalTranslation(state, diagnostics);
}
ReduceQuery(state, diagnostics);
}
}
void ReduceQuery(QueryTranslationState state, DiagnosticBag diagnostics)
{
var topClause = state.clauses.Pop();
if (topClause.Kind == SyntaxKind.WhereClause)
{
// A query expression with a where clause
// from x in e
// where f
// …
// is translated into
// from x in ( e ) . Where ( x => f )
var where = topClause as WhereClauseSyntax;
var lambda = MakeQueryUnboundLambda(state.QueryVariableMap(), state.queryVariable, where.Condition);
var invocation = MakeInvocation(where, state.fromExpression, "Where", lambda, diagnostics);
state.fromExpression = new BoundQueryClause(
syntax: where,
syntaxTree: SyntaxTree,
value: invocation,
definedSymbol: null,
queryMethod: invocation.Method,
castMethod: null,
type: invocation.Type);
}
else if (topClause.Kind == SyntaxKind.JoinClause && state.clauses.IsEmpty() && state.selectOrGroup.Kind == SyntaxKind.SelectClause)
{
var join = topClause as JoinClauseSyntax;
var select = state.selectOrGroup as SelectClauseSyntax;
var joinArgs = ArrayBuilder <BoundExpression> .GetInstance();
var e2 = BindValue(join.InExpression, BindValueKind.RValue, diagnostics);
MethodSymbol castMethod = null;
if (join.TypeOpt != null)
{
// A join clause that explicitly specifies a range variable type
// join T x in e on k1 equals k2
// is translated into
// join x in ( e ) . Cast < T > ( ) on k1 equals k2
var castType = BindType(join.TypeOpt, diagnostics);
var invocation = MakeInvocation(join, e2, "Cast", join.TypeOpt, castType, diagnostics);
castMethod = invocation.Method;
e2 = invocation;
}
joinArgs.Add(e2);
var lambda1 = MakeQueryUnboundLambda(state.QueryVariableMap(), state.queryVariable, join.LeftExpression);
joinArgs.Add(lambda1);
var x2 = state.AddQueryVariable(this, join.Identifier);
var lambda2 = MakeQueryUnboundLambda(state.QueryVariableMap(x2), x2, join.RightExpression); // TODO: ensure no other query variables in scope but x2.
joinArgs.Add(lambda2);
BoundExpression result;
if (join.IntoOpt == null)
{
// A query expression with a join clause without an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2
// select v
// is translated into
// ( e1 ) . Join( e2 , x1 => k1 , x2 => k2 , ( x1 , x2 ) => v )
var lambda3 = MakeQueryUnboundLambda(state.QueryVariableMap(), Args(state.queryVariable, x2), select.Expression);
// TODO: lambda3's body should be surrounded by a BoundQueryClause for the select clause.
joinArgs.Add(lambda3);
var invocation = MakeInvocation(join, state.fromExpression, "Join", joinArgs.ToReadOnlyAndFree(), diagnostics);
result = new BoundQueryClause(
syntax: join,
syntaxTree: SyntaxTree,
value: invocation,
definedSymbol: x2,
queryMethod: invocation.Method,
castMethod: castMethod,
type: invocation.Type);
}
else
{
// A query expression with a join clause with an into followed by a select clause
// from x1 in e1
// join x2 in e2 on k1 equals k2 into g
// select v
// is translated into
// ( e1 ) . GroupJoin( e2 , x1 => k1 , x2 => k2 , ( x1 , g ) => v )
var g = state.AddQueryVariable(this, join.IntoOpt.Identifier);
// binder.queryVariable = g; // TODO: where to record the info symbol?
var lambda3 = MakeQueryUnboundLambda(state.QueryVariableMap(), Args(state.queryVariable, g), select.Expression);
// TODO: lambda3's body should be surrounded by a BoundQueryClause for the select clause.
joinArgs.Add(lambda3);
var invocation = MakeInvocation(join, state.fromExpression, "GroupJoin", joinArgs.ToReadOnlyAndFree(), diagnostics);
var newArguments = Args(invocation.Arguments[0], invocation.Arguments[1], invocation.Arguments[2],
new BoundQueryClause( // record the into clause's symbol in the bound tree
syntax: join.IntoOpt,
syntaxTree: SyntaxTree,
value: invocation.Arguments[3],
definedSymbol: g,
queryMethod: null,
castMethod: null,
type: invocation.Arguments[3].Type));
invocation = invocation.Update(
receiverOpt: invocation.ReceiverOpt,
method: invocation.Method,
arguments: newArguments);
result = new BoundQueryClause(
syntax: join,
syntaxTree: SyntaxTree,
value: invocation,
definedSymbol: x2,
queryMethod: invocation.Method,
castMethod: castMethod,
type: invocation.Type);
}
state.Clear(); // this completes the whole query
state.fromExpression = result;
}
else if (topClause.Kind == SyntaxKind.OrderByClause)
{
// A query expression with an orderby clause
// from x in e
// orderby k1 , k2 , … , kn
// …
// is translated into
// from x in ( e ) .
// OrderBy ( x => k1 ) .
// ThenBy ( x => k2 ) .
// … .
// ThenBy ( x => kn )
// …
// If an ordering clause specifies a descending direction indicator,
// an invocation of OrderByDescending or ThenByDescending is produced instead.
var orderby = topClause as OrderByClauseSyntax;
bool first = true;
Symbol lastMethod = null;
foreach (var ordering in orderby.Orderings)
{
string methodName = (first ? "OrderBy" : "ThenBy") + (ordering.Kind == SyntaxKind.DescendingOrdering ? "Descending" : "");
var lambda = MakeQueryUnboundLambda(state.QueryVariableMap(), state.queryVariable, ordering.Expression);
var invocation = MakeInvocation(ordering, state.fromExpression, methodName, lambda, diagnostics);
lastMethod = invocation.Method;
state.fromExpression = new BoundQueryClause(
syntax: ordering, syntaxTree: SyntaxTree, value: invocation,
definedSymbol: null, queryMethod: invocation.Method, castMethod: null, type: invocation.Type);
first = false;
}
state.fromExpression = new BoundQueryClause(
syntax: orderby, syntaxTree: SyntaxTree, value: state.fromExpression,
definedSymbol: null, queryMethod: lastMethod, castMethod: null, type: state.fromExpression.Type);
}
else if (topClause.Kind == SyntaxKind.FromClause && state.clauses.IsEmpty() && state.selectOrGroup.Kind == SyntaxKind.SelectClause)
{
// A query expression with a second from clause followed by a select clause
// from x1 in e1
// from x2 in e2
// select v
// is translated into
// ( e1 ) . SelectMany( x1 => e2 , ( x1 , x2 ) => v )
var fromClause = topClause as FromClauseSyntax;
var select = state.selectOrGroup as SelectClauseSyntax;
var x1 = state.queryVariable;
TypeSymbol castType = fromClause.TypeOpt == null ? null : BindType(fromClause.TypeOpt, diagnostics);
BoundExpression lambda1 = MakeQueryUnboundLambda(state.QueryVariableMap(), x1, fromClause.Expression, fromClause.TypeOpt, castType);
// TODO: wrap the bound version of lambda1 in a BoundQueryClause for the from clause defining x2.
var x2 = state.AddQueryVariable(this, fromClause.Identifier);
BoundExpression lambda2 = MakeQueryUnboundLambda(state.QueryVariableMap(), Args(x1, x2), select.Expression);
var result = MakeInvocation(fromClause, state.fromExpression, "SelectMany", Args(lambda1, lambda2), diagnostics);
// TODO: extract the Cast<T>() operation from the bound version of lambda1 (this invocation's first argument) and store it in e2Binder.castMethod
state.Clear();
state.fromExpression = new BoundQueryClause(
syntax: select, syntaxTree: SyntaxTree, value: result,
definedSymbol: null, queryMethod: result.Method, castMethod: null, type: result.Type);
}
else if (topClause.Kind == SyntaxKind.LetClause)
{
var let = topClause as LetClauseSyntax;
var x = state.queryVariable;
// A query expression with a let clause
// from x in e
// let y = f
// …
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// …
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result. We place
// this mapping into the state and then, subsequently, into the binder
// for any further clauses.
LambdaBodyResolver resolver = (LambdaSymbol lambdaSymbol, ExecutableCodeBinder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaBodyBinder.SyntaxTree, lambdaSymbol.Parameters[0]);
var yExpression = lambdaBodyBinder.BindValue(let.Expression, BindValueKind.RValue, d);
var construction = MakePair(let, xExpression, yExpression, d);
return(lambdaBodyBinder.WrapExpressionLambdaBody(construction, let, d));
};
var lambda = MakeQueryUnboundLambda(state.QueryVariableMap(), x, let.Expression, resolver);
state.queryVariable = state.TransparentQueryVariable(this);
var invocation = MakeInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.AddTransparentIdentifier("Item1");
var y = state.AddQueryVariable(this, let.Identifier);
state.allQueryVariables[y].Add("Item2");
state.fromExpression = new BoundQueryClause(
syntax: let, syntaxTree: SyntaxTree, value: invocation,
definedSymbol: y, queryMethod: invocation.Method, castMethod: null, type: invocation.Type);
}
else
{
diagnostics.Add(ErrorCode.ERR_NotYetImplementedInRoslyn, Location(topClause), "query expression");
var result = state.fromExpression; // short circuit any remaining reductions
state.Clear();
state.fromExpression = result;
}
}
private void ReduceQuery(QueryTranslationState state, DiagnosticBag diagnostics)
{
var topClause = state.clauses.Pop();
switch (topClause.Kind())
{
case SyntaxKind.WhereClause:
ReduceWhere((WhereClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.JoinClause:
ReduceJoin((JoinClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.OrderByClause:
ReduceOrderBy((OrderByClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.FromClause:
ReduceFrom((FromClauseSyntax)topClause, state, diagnostics);
break;
case SyntaxKind.LetClause:
ReduceLet((LetClauseSyntax)topClause, state, diagnostics);
break;
default:
throw ExceptionUtilities.UnexpectedValue(topClause.Kind());
}
}
internal BoundExpression BindQueryInternal1(QueryExpressionSyntax node, DiagnosticBag diagnostics)
{
var fromClause = (FromClauseSyntax)node.Clauses[0];
QueryTranslationState state = new QueryTranslationState();
state.fromSyntax = fromClause;
state.fromExpression = BindValue(fromClause.Expression, BindValueKind.RValue, diagnostics);
state.queryVariable = state.AddQueryVariable(this, fromClause.Identifier);
for (int i = node.Clauses.Count - 1; i > 0; i--)
{
state.clauses.Push(node.Clauses[i]);
}
state.selectOrGroup = node.SelectOrGroup;
// A from clause that explicitly specifies a range variable type
// from T x in e
// is translated into
// from x in ( e ) . Cast < T > ( )
MethodSymbol castMethod = null;
if (fromClause.TypeOpt != null)
{
var typeRestriction = BindType(fromClause.TypeOpt, diagnostics);
var cast = MakeInvocation(state.fromSyntax, state.fromExpression, "Cast", fromClause.TypeOpt, typeRestriction, diagnostics);
castMethod = cast.Method;
state.fromExpression = cast;
}
state.fromExpression = new BoundQueryClause(
syntax: fromClause,
syntaxTree: this.SyntaxTree,
value: state.fromExpression,
definedSymbol: state.queryVariable,
queryMethod: null,
castMethod: castMethod,
type: state.fromExpression.Type);
// If the query is a degenerate one the form "from x in e select x", but in source,
// then we go ahead and generate the select anyway. We do this by skipping BindQueryInternal2,
// whose job it is to (reduce away the whole query and) optimize away degenerate queries.
BoundExpression result = (fromClause.TypeOpt == null && IsDegenerateQuery(state))
? FinalTranslation(state, diagnostics)
: BindQueryInternal2(state, diagnostics);
QueryContinuationSyntax continuation = node.ContinuationOpt;
while (continuation != null)
{
// A query expression with a continuation
// from … into x …
// is translated into
// from x in ( from … ) …
state.Clear();
state.fromExpression = result;
var x = state.AddQueryVariable(this, continuation.Identifier);
state.fromExpression = new BoundQueryClause(
syntax: continuation,
syntaxTree: SyntaxTree,
value: state.fromExpression,
definedSymbol: x,
queryMethod: null,
castMethod: null,
type: state.fromExpression.Type);
state.queryVariable = x;
Debug.Assert(state.clauses.IsEmpty());
var clauses = continuation.Query.Clauses;
for (int i = clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(clauses[i]);
}
state.selectOrGroup = continuation.Query.SelectOrGroup;
result = BindQueryInternal2(state, diagnostics);
continuation = continuation.Query.ContinuationOpt;
}
state.Free();
return(result);
}
private void ReduceLet(LetClauseSyntax let, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a let clause
// from x in e
// let y = f
// ...
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// ...
var x = state.rangeVariable;
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, ref Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaSymbol.Parameters[0]) { WasCompilerGenerated = true };
var yExpression = lambdaBodyBinder.BindValue(let.Expression, d, BindValueKind.RValue);
SourceLocation errorLocation = new SourceLocation(let.SyntaxTree, new TextSpan(let.Identifier.SpanStart, let.Expression.Span.End - let.Identifier.SpanStart));
if (!yExpression.HasAnyErrors && !yExpression.HasExpressionType())
{
MessageID id = MessageID.IDS_NULL;
if (yExpression.Kind == BoundKind.UnboundLambda)
{
id = ((UnboundLambda)yExpression).MessageID;
}
else if (yExpression.Kind == BoundKind.MethodGroup)
{
id = MessageID.IDS_MethodGroup;
}
else
{
Debug.Assert(yExpression.IsLiteralNull(), "How did we successfully bind an expression without a type?");
}
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, id.Localize());
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(yExpression), CreateErrorType());
}
else if (!yExpression.HasAnyErrors && yExpression.Type.SpecialType == SpecialType.System_Void)
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Type);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(yExpression), yExpression.Type);
}
var construction = MakePair(let, x.Name, xExpression, let.Identifier.ValueText, yExpression, state, d);
return lambdaBodyBinder.CreateBlockFromExpression(let, lambdaBodyBinder.Locals, null, construction, d);
};
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x), let.Expression, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x.Name);
var y = state.AddRangeVariable(this, let.Identifier, diagnostics);
state.allRangeVariables[y].Add(let.Identifier.ValueText);
var invocation = MakeQueryInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.fromExpression = MakeQueryClause(let, invocation, y, invocation);
}
private UnboundLambda MakePairLambda(CSharpSyntaxNode node, QueryTranslationState state, RangeVariableSymbol x1, RangeVariableSymbol x2)
{
Debug.Assert(LambdaUtilities.IsQueryPairLambda(node));
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var x1Expression = new BoundParameter(node, lambdaSymbol.Parameters[0]) { WasCompilerGenerated = true };
var x2Expression = new BoundParameter(node, lambdaSymbol.Parameters[1]) { WasCompilerGenerated = true };
var construction = MakePair(node, x1.Name, x1Expression, x2.Name, x2Expression, state, d);
return lambdaBodyBinder.CreateBlockFromExpression(node, ImmutableArray<LocalSymbol>.Empty, RefKind.None, construction, null, d);
};
var result = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, x2), node, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x1.Name);
var x2m = state.allRangeVariables[x2];
x2m[x2m.Count - 1] = x2.Name;
return result;
}
private void ReduceFrom(FromClauseSyntax from, QueryTranslationState state, DiagnosticBag diagnostics)
{
var x1 = state.rangeVariable;
BoundExpression collectionSelectorLambda;
if (from.Type == null)
{
collectionSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), x1, from.Expression);
}
else
{
collectionSelectorLambda = MakeQueryUnboundLambdaWithCast(state.RangeVariableMap(), x1, from.Expression, from.Type, BindTypeArgument(from.Type, diagnostics));
}
var x2 = state.AddRangeVariable(this, from.Identifier, diagnostics);
if (state.clauses.IsEmpty() && state.selectOrGroup.IsKind(SyntaxKind.SelectClause))
{
var select = (SelectClauseSyntax)state.selectOrGroup;
// A query expression with a second from clause followed by a select clause
// from x1 in e1
// from x2 in e2
// select v
// is translated into
// ( e1 ) . SelectMany( x1 => e2 , ( x1 , x2 ) => v )
var resultSelectorLambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x1, x2), select.Expression);
var invocation = MakeQueryInvocation(
from,
state.fromExpression,
"SelectMany",
ImmutableArray.Create(collectionSelectorLambda, resultSelectorLambda),
diagnostics);
// Adjust the second-to-last parameter to be a query clause (if it was an extension method, an extra parameter was added)
BoundExpression castInvocation = (from.Type != null) ? ExtractCastInvocation(invocation) : null;
var arguments = invocation.Arguments;
invocation = invocation.Update(
invocation.ReceiverOpt,
invocation.Method,
arguments.SetItem(arguments.Length - 2, MakeQueryClause(from, arguments[arguments.Length - 2], x2, invocation, castInvocation)));
state.Clear();
state.fromExpression = MakeQueryClause(from, invocation, definedSymbol: x2, queryInvocation: invocation);
state.fromExpression = MakeQueryClause(select, state.fromExpression);
}
else
{
// A query expression with a second from clause followed by something other than a select clause:
// from x1 in e1
// from x2 in e2
// ...
// is translated into
// from * in ( e1 ) . SelectMany( x1 => e2 , ( x1 , x2 ) => new { x1 , x2 } )
// ...
// We use a slightly different translation strategy. We produce
// from * in ( e ) . SelectMany ( x1 => e2, ( x1 , x2 ) => new Pair<X1,X2>(x1, x2) )
// Where X1 is the type of x1, and X2 is the type of x2.
// Subsequently, x1 (or members of x1, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and x2 is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
var resultSelectorLambda = MakePairLambda(from, state, x1, x2);
var invocation = MakeQueryInvocation(
from,
state.fromExpression,
"SelectMany",
ImmutableArray.Create(collectionSelectorLambda, resultSelectorLambda),
diagnostics);
BoundExpression castInvocation = (from.Type != null) ? ExtractCastInvocation(invocation) : null;
state.fromExpression = MakeQueryClause(from, invocation, x2, invocation, castInvocation);
}
}
private static bool IsDegenerateQuery(QueryTranslationState state)
{
if (!state.clauses.IsEmpty()) return false;
// A degenerate query is of the form "from x in e select x".
var select = state.selectOrGroup as SelectClauseSyntax;
if (select == null) return false;
var name = select.Expression as IdentifierNameSyntax;
return name != null && state.rangeVariable.Name == name.Identifier.ValueText;
}
internal BoundExpression BindQuery(QueryExpressionSyntax node, DiagnosticBag diagnostics)
{
var fromClause = node.FromClause;
var boundFromExpression = BindLeftOfPotentialColorColorMemberAccess(fromClause.Expression, diagnostics);
// If the from expression is of the type dynamic we can't infer the types for any lambdas that occur in the query.
// Only if there are none we could bind the query but we report an error regardless since such queries are not useful.
if (boundFromExpression.HasDynamicType())
{
diagnostics.Add(ErrorCode.ERR_BadDynamicQuery, fromClause.Expression.Location);
boundFromExpression = BadExpression(fromClause.Expression, boundFromExpression);
}
QueryTranslationState state = new QueryTranslationState();
state.fromExpression = MakeMemberAccessValue(boundFromExpression, diagnostics);
var x = state.rangeVariable = state.AddRangeVariable(this, fromClause.Identifier, diagnostics);
for (int i = node.Body.Clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(node.Body.Clauses[i]);
}
state.selectOrGroup = node.Body.SelectOrGroup;
// A from clause that explicitly specifies a range variable type
// from T x in e
// is translated into
// from x in ( e ) . Cast < T > ( )
BoundExpression cast = null;
if (fromClause.Type != null)
{
var typeRestriction = BindTypeArgument(fromClause.Type, diagnostics);
cast = MakeQueryInvocation(fromClause, state.fromExpression, "Cast", fromClause.Type, typeRestriction, diagnostics);
state.fromExpression = cast;
}
state.fromExpression = MakeQueryClause(fromClause, state.fromExpression, x, castInvocation: cast);
BoundExpression result = BindQueryInternal1(state, diagnostics);
for (QueryContinuationSyntax continuation = node.Body.Continuation; continuation != null; continuation = continuation.Body.Continuation)
{
// A query expression with a continuation
// from ... into x ...
// is translated into
// from x in ( from ... ) ...
state.Clear();
state.fromExpression = result;
x = state.rangeVariable = state.AddRangeVariable(this, continuation.Identifier, diagnostics);
Debug.Assert(state.clauses.IsEmpty());
var clauses = continuation.Body.Clauses;
for (int i = clauses.Count - 1; i >= 0; i--)
{
state.clauses.Push(clauses[i]);
}
state.selectOrGroup = continuation.Body.SelectOrGroup;
result = BindQueryInternal1(state, diagnostics);
result = MakeQueryClause(continuation.Body, result, x);
result = MakeQueryClause(continuation, result, x);
}
state.Free();
return MakeQueryClause(node, result);
}
private void ReduceOrderBy(OrderByClauseSyntax orderby, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with an orderby clause
// from x in e
// orderby k1 , k2 , ... , kn
// ...
// is translated into
// from x in ( e ) .
// OrderBy ( x => k1 ) .
// ThenBy ( x => k2 ) .
// ... .
// ThenBy ( x => kn )
// ...
// If an ordering clause specifies a descending direction indicator,
// an invocation of OrderByDescending or ThenByDescending is produced instead.
bool first = true;
foreach (var ordering in orderby.Orderings)
{
string methodName = (first ? "OrderBy" : "ThenBy") + (ordering.IsKind(SyntaxKind.DescendingOrdering) ? "Descending" : "");
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), state.rangeVariable, ordering.Expression);
var invocation = MakeQueryInvocation(ordering, state.fromExpression, methodName, lambda, diagnostics);
state.fromExpression = MakeQueryClause(ordering, invocation, queryInvocation: invocation);
first = false;
}
state.fromExpression = MakeQueryClause(orderby, state.fromExpression);
}
private BoundExpression MakePair(CSharpSyntaxNode node, string field1Name, BoundExpression field1Value, string field2Name, BoundExpression field2Value, QueryTranslationState state, DiagnosticBag diagnostics)
{
if (field1Name == field2Name)
{
// we will generate a diagnostic elsewhere
field2Name = state.TransparentRangeVariableName();
field2Value = new BoundBadExpression(field2Value.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create(field2Value), field2Value.Type, true);
}
AnonymousTypeDescriptor typeDescriptor = new AnonymousTypeDescriptor(
ImmutableArray.Create <AnonymousTypeField>(
new AnonymousTypeField(field1Name, field1Value.Syntax.Location, TypeOrError(field1Value)),
new AnonymousTypeField(field2Name, field2Value.Syntax.Location, TypeOrError(field2Value))
),
node.Location
);
AnonymousTypeManager manager = this.Compilation.AnonymousTypeManager;
NamedTypeSymbol anonymousType = manager.ConstructAnonymousTypeSymbol(typeDescriptor);
return(MakeConstruction(node, anonymousType, ImmutableArray.Create(field1Value, field2Value), diagnostics));
}
void ReduceLet(LetClauseSyntax let, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a let clause
// from x in e
// let y = f
// ...
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// ...
var x = state.rangeVariable;
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
LambdaBodyResolver resolver = (LambdaSymbol lambdaSymbol, ref Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaSymbol.Parameters[0])
{
WasCompilerGenerated = true
};
lambdaBodyBinder = new ScopedExpressionBinder(lambdaBodyBinder, let.Expression);
var yExpression = lambdaBodyBinder.BindValue(let.Expression, d, BindValueKind.RValue);
SourceLocation errorLocation = new SourceLocation(let.SyntaxTree, new TextSpan(let.Identifier.SpanStart, let.Expression.Span.End - let.Identifier.SpanStart));
if (!yExpression.HasAnyErrors && !yExpression.HasExpressionType())
{
MessageID id = MessageID.IDS_NULL;
if (yExpression.Kind == BoundKind.UnboundLambda)
{
id = ((UnboundLambda)yExpression).MessageID;
}
else if (yExpression.Kind == BoundKind.MethodGroup)
{
id = MessageID.IDS_MethodGroup;
}
else
{
Debug.Assert(yExpression.IsLiteralNull(), "How did we successfully bind an expression without a type?");
}
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, id.Localize());
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(yExpression), CreateErrorType());
}
else if (!yExpression.HasAnyErrors && yExpression.Type.SpecialType == SpecialType.System_Void)
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Type);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray <Symbol> .Empty, ImmutableArray.Create <BoundNode>(yExpression), yExpression.Type);
}
var construction = MakePair(let, x.Name, xExpression, let.Identifier.ValueText, yExpression, state, d);
return(lambdaBodyBinder.CreateBlockFromExpression(lambdaBodyBinder.Locals, construction, let, d));
};
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), x, let.Expression, resolver);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x.Name);
var y = state.AddRangeVariable(this, let.Identifier, diagnostics);
state.allRangeVariables[y].Add(let.Identifier.ValueText);
var invocation = MakeQueryInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.fromExpression = MakeQueryClause(let, invocation, y, invocation);
}
private BoundExpression FinalTranslation(QueryTranslationState state, DiagnosticBag diagnostics)
{
Debug.Assert(state.clauses.IsEmpty());
switch (state.selectOrGroup.Kind)
{
case SyntaxKind.SelectClause:
{
// A query expression of the form
// from x in e select v
// is translated into
// ( e ) . Select ( x => v )
var selectClause = (SelectClauseSyntax)state.selectOrGroup;
var x = state.queryVariable;
var e = state.fromExpression;
var v = selectClause.Expression;
var lambda = MakeQueryUnboundLambda(state.QueryVariableMap(), x, v);
var result = MakeInvocation(state.selectOrGroup, e, "Select", lambda, diagnostics);
return(new BoundQueryClause(
syntax: selectClause,
syntaxTree: SyntaxTree,
value: result,
definedSymbol: null,
queryMethod: null,
castMethod: null,
type: result.Type));
}
case SyntaxKind.GroupClause:
{
// A query expression of the form
// from x in e group v by k
// is translated into
// ( e ) . GroupBy ( x => k , x => v )
// except when v is the identifier x, the translation is
// ( e ) . GroupBy ( x => k )
var groupClause = (GroupClauseSyntax)state.selectOrGroup;
var x = state.queryVariable;
var e = state.fromExpression;
var v = groupClause.GroupExpression;
var k = groupClause.ByExpression;
var vId = v as IdentifierNameSyntax;
BoundCall result;
if (vId != null && vId.Identifier.ValueText == x.Name)
{
var lambda = MakeQueryUnboundLambda(state.QueryVariableMap(), x, k);
result = MakeInvocation(state.selectOrGroup, e, "GroupBy", lambda, diagnostics);
}
else
{
BoundExpression lambdaLeft = MakeQueryUnboundLambda(state.QueryVariableMap(), x, k);
BoundExpression lambdaRight = MakeQueryUnboundLambda(state.QueryVariableMap(), x, v);
result = MakeInvocation(state.selectOrGroup, e, "GroupBy", Args(lambdaLeft, lambdaRight), diagnostics);
}
return(new BoundQueryClause(
syntax: groupClause,
syntaxTree: syntaxTree,
value: result,
definedSymbol: null,
queryMethod: result.Method,
castMethod: null,
type: result.Type));
}
default:
{
// there should have been a syntax error if we get here.
return(new BoundBadExpression(
state.selectOrGroup, SyntaxTree, LookupResultKind.OverloadResolutionFailure, ReadOnlyArray <Symbol> .Empty,
Args <BoundNode>(state.fromExpression), state.fromExpression.Type));
}
}
}
private void ReduceLet(LetClauseSyntax let, QueryTranslationState state, DiagnosticBag diagnostics)
{
// A query expression with a let clause
// from x in e
// let y = f
// ...
// is translated into
// from * in ( e ) . Select ( x => new { x , y = f } )
// ...
var x = state.rangeVariable;
// We use a slightly different translation strategy. We produce
// from * in ( e ) . Select ( x => new Pair<X,Y>(x, f) )
// Where X is the type of x, and Y is the type of the expression f.
// Subsequently, x (or members of x, if it is a transparent identifier)
// are accessed as TRID.Item1 (or members of that), and y is accessed
// as TRID.Item2, where TRID is the compiler-generated identifier used
// to represent the transparent identifier in the result.
LambdaBodyFactory bodyFactory = (LambdaSymbol lambdaSymbol, Binder lambdaBodyBinder, DiagnosticBag d) =>
{
var xExpression = new BoundParameter(let, lambdaSymbol.Parameters[0]) { WasCompilerGenerated = true };
lambdaBodyBinder = lambdaBodyBinder.GetBinder(let.Expression);
Debug.Assert(lambdaBodyBinder != null);
var yExpression = lambdaBodyBinder.BindValue(let.Expression, d, BindValueKind.RValue);
SourceLocation errorLocation = new SourceLocation(let.SyntaxTree, new TextSpan(let.Identifier.SpanStart, let.Expression.Span.End - let.Identifier.SpanStart));
if (!yExpression.HasAnyErrors && !yExpression.HasExpressionType())
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Display);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(yExpression), CreateErrorType());
}
else if (!yExpression.HasAnyErrors && yExpression.Type.SpecialType == SpecialType.System_Void)
{
Error(d, ErrorCode.ERR_QueryRangeVariableAssignedBadValue, errorLocation, yExpression.Type);
yExpression = new BoundBadExpression(yExpression.Syntax, LookupResultKind.Empty, ImmutableArray<Symbol>.Empty, ImmutableArray.Create<BoundNode>(yExpression), yExpression.Type);
}
var construction = MakePair(let, x.Name, xExpression, let.Identifier.ValueText, yExpression, state, d);
// The bound block represents a closure scope for transparent identifiers captured in the let clause.
// Such closures shall be associated with the lambda body expression.
return lambdaBodyBinder.CreateBlockFromExpression(let.Expression, lambdaBodyBinder.GetDeclaredLocalsForScope(let.Expression), RefKind.None, construction, null, d);
};
var lambda = MakeQueryUnboundLambda(state.RangeVariableMap(), ImmutableArray.Create(x), let.Expression, bodyFactory);
state.rangeVariable = state.TransparentRangeVariable(this);
state.AddTransparentIdentifier(x.Name);
var y = state.AddRangeVariable(this, let.Identifier, diagnostics);
state.allRangeVariables[y].Add(let.Identifier.ValueText);
var invocation = MakeQueryInvocation(let, state.fromExpression, "Select", lambda, diagnostics);
state.fromExpression = MakeQueryClause(let, invocation, y, invocation);
}
