/// <summary> /// Process the First/last. This means adding a pointer (or not if we are looking at a plane type) and /// then filling it till it is full or filling it till the loop is done. Bomb out if we are asked to at the end!! /// </summary> /// <param name="resultOperator"></param> /// <param name="queryModel"></param> /// <param name="_codeEnv"></param> /// <returns></returns> public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, IGeneratedQueryCode gc, ICodeContext cc, CompositionContainer container) { /// /// First, do data normalization /// var asFirst = resultOperator as FirstResultOperator; var asLast = resultOperator as LastResultOperator; if (asFirst == null && asLast == null) { throw new ArgumentNullException("First/Last operator must be either first or last, and not null!"); } bool isFirst = asFirst != null; bool bombIfNothing = true; if (isFirst) { bombIfNothing = !asFirst.ReturnDefaultWhenEmpty; } else { bombIfNothing = !asLast.ReturnDefaultWhenEmpty; } // // Figure out if we need to cache the result: // - simple variable which has a default value which can be used later on. // like a double, etc. // - We actually allow for a default variable. // bool cacheResult = cc.LoopVariable.Type.IsNumberType(); cacheResult = cacheResult && !bombIfNothing; // // Next, make sure we are looping over something. This had better be an array we are looking at! // if (cc.LoopIndexVariable == null) { throw new InvalidOperationException(string.Format("Can't apply First operator when we aren't looping over some well formed array '{0}'", cc.LoopVariable.ToString())); } var indexExpr = cc.LoopIndexVariable; // // We need to hold onto either the first or the last item here, so we create a statement that holds nnto the // first or the last time. It also has to mark the thing as valid! It will break when it is done. // While the bool can be used later on to get at the exception we might be throwing, the actual // result may be used much further on down. To protect against that, we set the array index to be -1, // and then hope there is a crash later on! :-) // // It is possible that this is part of a dual selection. For example, if you are interested in the jet that has the closest track, and the // loop is constructed over the jets first, and then the tracks. This First will likely be for a track index, but we will be looking up the // track later. So we need to record both the jet and track index. To get the other indicies, we just look for all loop variables between here and // the result scope. // var valueWasSeen = DeclarableParameter.CreateDeclarableParameterExpression(typeof(bool)); var indexSeen = DeclarableParameter.CreateDeclarableParameterExpression(indexExpr.Type); if (indexSeen.Type.IsNumberType()) { indexSeen.SetInitialValue("-1"); } gc.AddAtResultScope(valueWasSeen); gc.AddAtResultScope(indexSeen); var rv = new Statements.StatementRecordValue(indexSeen, indexExpr, valueWasSeen, isFirst); gc.Add(rv); foreach (var v in gc.GetUsedQuerySourceVariables(rv, indexExpr)) { var saver = DeclarableParameter.CreateDeclarableParameterExpression(v.Type); gc.AddAtResultScope(saver); rv.AddNewSaver(saver, v); cc.Add(v.RawValue, saver); } gc.Pop(true); if (bombIfNothing) { var test = ExpressionToCPP.GetExpression(Expression.Not(valueWasSeen), gc, cc, container); gc.Add(new Statements.StatementThrowIfTrue(test, string.Format("First/Last predicate executed on a null sequence: {0}", queryModel.ToString()))); } // // Finally, we need the new expression. For this we basically just ask for the translated expression. We // also add a substitution for later on for more complex expressions. // var firstlastValue = cc.LoopVariable; cc.Add(indexExpr.RawValue, indexSeen); Debug.WriteLine("First/Last: {0} for QM {1}", indexSeen.ToString(), queryModel.ToString()); // Reset the expression we are looking at in the loop. var newIndexExpr = firstlastValue.ReplaceSubExpression(indexExpr.AsExpression(), indexSeen); cc.SetLoopVariable(newIndexExpr, indexSeen); if (cacheResult) { // // Set the default value // var actualValue = DeclarableParameter.CreateDeclarableParameterExpression(cc.LoopVariable.Type); actualValue.SetInitialValue("0"); // // If everything went well, then we can do the assignment. Otherwise, we leave // it as above (having the default value). // gc.Add(new Statements.StatementFilter(valueWasSeen)); gc.Add(new Statements.StatementAssign(actualValue, ExpressionToCPP.GetExpression(firstlastValue, gc, cc, container))); gc.Pop(); return(actualValue); } else { // No need to cache the result - so no need to add extra code. return(newIndexExpr); } }
/// <summary> /// Process the First/last. This means adding a pointer (or not if we are looking at a plane type) and /// then filling it till it is full or filling it till the loop is done. Bomb out if we are asked to at the end!! /// </summary> /// <param name="resultOperator"></param> /// <param name="queryModel"></param> /// <param name="_codeEnv"></param> /// <returns></returns> public Expression ProcessResultOperator(ResultOperatorBase resultOperator, QueryModel queryModel, IGeneratedQueryCode gc, ICodeContext cc, CompositionContainer container) { /// /// First, do data normalization /// var asFirst = resultOperator as FirstResultOperator; var asLast = resultOperator as LastResultOperator; if (asFirst == null && asLast == null) { throw new ArgumentNullException("First/Last operator must be either first or last, and not null!"); } bool isFirst = asFirst != null; bool bombIfNothing = true; if (isFirst) { bombIfNothing = !asFirst.ReturnDefaultWhenEmpty; } else { bombIfNothing = !asLast.ReturnDefaultWhenEmpty; } // // Figure out if we need to cache the result: // - simple variable which has a default value which can be used later on. // like a double, etc. // - We actually allow for a default variable. // bool cacheResult = cc.LoopVariable.Type.IsNumberType(); cacheResult = cacheResult && !bombIfNothing; // // Next, make sure we are looping over something. This had better be an array we are looking at! // if (cc.LoopIndexVariable == null) { throw new InvalidOperationException(string.Format("Can't apply First operator when we aren't looping over some well formed array '{0}'", cc.LoopVariable.ToString())); } var indexExpr = cc.LoopIndexVariable; // // We need to hold onto either the first or the last item here, so we create a statement that holds nnto the // first or the last time. It also has to mark the thing as valid! It will break when it is done. // While the bool can be used later on to get at the exception we might be throwing, the actual // result may be used much further on down. To protect against that, we set the array index to be -1, // and then hope there is a crash later on! :-) // // It is possible that this is part of a dual selection. For example, if you are interested in the jet that has the closest track, and the // loop is constructed over the jets first, and then the tracks. This First will likely be for a track index, but we will be looking up the // track later. So we need to record both the jet and track index. To get the other indicies, we just look for all loop variables between here and // the result scope. // var valueWasSeen = DeclarableParameter.CreateDeclarableParameterExpression(typeof(bool)); var indexSeen = DeclarableParameter.CreateDeclarableParameterExpression(indexExpr.Type); if (indexSeen.Type.IsNumberType()) indexSeen.SetInitialValue("-1"); gc.AddAtResultScope(valueWasSeen); gc.AddAtResultScope(indexSeen); var rv = new Statements.StatementRecordValue(indexSeen, indexExpr, valueWasSeen, isFirst); gc.Add(rv); foreach (var v in gc.GetUsedQuerySourceVariables(rv, indexExpr)) { var saver = DeclarableParameter.CreateDeclarableParameterExpression(v.Type); gc.AddAtResultScope(saver); rv.AddNewSaver(saver, v); cc.Add(v.RawValue, saver); } gc.Pop(true); if (bombIfNothing) { var test = ExpressionToCPP.GetExpression(Expression.Not(valueWasSeen), gc, cc, container); gc.Add(new Statements.StatementThrowIfTrue(test, string.Format("First/Last predicate executed on a null sequence: {0}", queryModel.ToString()))); } // // Finally, we need the new expression. For this we basically just ask for the translated expression. We // also add a substitution for later on for more complex expressions. // var firstlastValue = cc.LoopVariable; cc.Add(indexExpr.RawValue, indexSeen); Debug.WriteLine("First/Last: {0} for QM {1}", indexSeen.ToString(), queryModel.ToString()); // Reset the expression we are looking at in the loop. var newIndexExpr = firstlastValue.ReplaceSubExpression(indexExpr.AsExpression(), indexSeen); cc.SetLoopVariable(newIndexExpr, indexSeen); if (cacheResult) { // // Set the default value // var actualValue = DeclarableParameter.CreateDeclarableParameterExpression(cc.LoopVariable.Type); actualValue.SetInitialValue("0"); // // If everything went well, then we can do the assignment. Otherwise, we leave // it as above (having the default value). // gc.Add(new Statements.StatementFilter(valueWasSeen)); gc.Add(new Statements.StatementAssign(actualValue, ExpressionToCPP.GetExpression(firstlastValue, gc, cc, container))); gc.Pop(); return actualValue; } else { // No need to cache the result - so no need to add extra code. return newIndexExpr; } }