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));
}
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);
}
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 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));
}
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 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);
}
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 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 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);
}