public QueryUnboundLambdaState(UnboundLambda unbound, Binder binder, RangeVariableMap rangeVariableMap, ImmutableArray <RangeVariableSymbol> parameters, LambdaBodyResolver bodyResolver)
: base(unbound, binder)
{
this.parameters = parameters;
this.bodyResolver = bodyResolver;
this.rangeVariableMap = rangeVariableMap;
}
public QueryUnboundLambdaState(UnboundLambda unbound, Binder binder, RangeVariableMap rangeVariableMap, ImmutableArray<RangeVariableSymbol> parameters, LambdaBodyResolver bodyResolver)
: base(unbound, binder)
{
this.parameters = parameters;
this.bodyResolver = bodyResolver;
this.rangeVariableMap = rangeVariableMap;
}
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);
}
UnboundLambda MakeQueryUnboundLambda(RangeVariableMap qvm, ImmutableArray <RangeVariableSymbol> parameters, CSharpSyntaxNode node, LambdaBodyResolver resolver)
{
var state = new QueryUnboundLambdaState(null, this, qvm, parameters, resolver);
var lambda = new UnboundLambda(node, state, false)
{
WasCompilerGenerated = true
};
state.SetUnboundLambda(lambda);
return(lambda);
}
UnboundLambda MakeQueryUnboundLambda(RangeVariableMap qvm, RangeVariableSymbol parameter, CSharpSyntaxNode node, LambdaBodyResolver resolver)
{
return(MakeQueryUnboundLambda(qvm, Args(parameter), node, resolver));
}
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);
}
UnboundLambda MakeQueryUnboundLambda(QueryVariableMap qvm, ReadOnlyArray <QueryVariableSymbol> parameters, SyntaxNode node, LambdaBodyResolver resolver)
{
var state = new QueryUnboundLambdaState(null, this, qvm, parameters, resolver);
var lambda = new UnboundLambda(node, SyntaxTree, state, false);
state.SetUnboundLambda(lambda);
return(lambda);
}
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;
}
}
