public override bool Visit(ILinqBody body, ILinqBody context)
{
_stack.Push(body);
try
{
return(base.Visit(body, context));
}
finally
{
_stack.Pop();
}
}
/// <summary>
/// Creates a new <see cref="LinqFusionSelectBody"/> with the
/// <paramref name="selection"/>, <paramref name="target"/>,
/// and <paramref name="next"/> provided.
/// </summary>
/// <param name="selection">The <see cref="IExpression"/>
/// which denotes what is selected as a result of the
/// language integrated query.</param>
/// <param name="target">The <see cref="String"/> representing the name of the
/// range variable that the data from the grouped query is stored into.</param>
/// <param name="next">The <see cref="ILinqBody"/> which
/// continues the language integrated query.</param>
public LinqFusionSelectBody(IExpression selection, string target, ILinqBody next)
: base(selection)
{
this.target = new LinqRangeVariable(this, target);
this.Next = next;
}
/// <summary>
/// Creates a new <see cref="LinqFusionGroupBody"/> with
/// the <paramref name="selection"/>, <paramref name="key"/>,
/// <paramref name="target"/> and <paramref name="next"/>
/// provided.
/// </summary>
/// <param name="selection">The <see cref="IExpression"/> which
/// acts as a selector on the data set to retrieve the data for the query.</param>
/// <param name="key">The <see cref="IExpression"/> which acts
/// as the key for grouping the <see cref="ILinqSelectBody.Selection"/>s.</param>
/// <param name="target">The <see cref="String"/> representing the name of the
/// range variable that the data from the grouped query is stored into.</param>
/// <param name="next">The <see cref="ILinqBody"/> which
/// continues the language integrated query.</param>
public LinqFusionGroupBody(IExpression selection, IExpression key, string target, ILinqBody next)
: base(selection, target, next)
{
this.Key = key;
}
public ILinqExpression Build()
{
var path = new Stack <ILinqBodyBuilderParent>();
//Build a reverse-order listing of the current expression graph.
for (ILinqBodyBuilderParent current = this; current != null; path.Push(current), current = current.Parent)
{
;
}
ILinqExpression result = new LinqExpression();
int bodyCount = 0;
var pathNodes = path.ToArray();
const int selectBody = 1,
selectFuseBody = 3;
const int groupBody = 2,
groupFuseBody = 4;
//Count the number of body continuations.
for (int i = 0; i < pathNodes.Length; i++)
{
if (pathNodes[i] is ILinqTailBodyBuilder)
{
bodyCount++;
}
}
int[] bodyTypes = new int[bodyCount];
int bodyIndex = 0;
/* *
* Iterate through and, from the tails, discern
* the kind of body to use.
* */
for (int i = 0; i < pathNodes.Length; i++)
{
if (pathNodes[i] is ILinqTailBodyBuilder)
{
bool last = i == pathNodes.Length - 1;
if (pathNodes[i] is LinqTailGroupBodyBuilder)
{
bodyTypes[bodyIndex++] = last ? groupBody : groupFuseBody;
}
else
{
bodyTypes[bodyIndex++] = last ? selectBody : selectFuseBody;
}
}
}
ILinqBody currentBody = null;
bodyIndex = 0;
var selector = pathNodes[0] as LinqTypedFromBodyBuilder;
/* *
* The first element is always a from clause, either typed or
* untyped.
* *
* This is why initialization pipeline is closed.
* */
if (selector == null)
{
result.From = BuildFromClause(pathNodes[0] as LinqFromBodyBuilder);
}
else
{
result.From = BuildFromClause(selector);
}
/* *
* Iterate through the elements and build the bodies,
* linking the clauses in between.
* */
for (int i = 1; i < pathNodes.Length; i++)
{
bool last = i == pathNodes.Length - 1;
/* *
* Create the initial body from the current element.
* */
if (currentBody == null)
{
currentBody = result.Body = GetBody(bodyTypes[bodyIndex++]);
if (currentBody == null)
{
throw new InvalidOperationException("Unknown error.");
}
}
/* *
* This breaks programming practice rules, bite me.
* */
var fromClauseT = pathNodes[i] as LinqTypedFromBodyBuilder;
if (fromClauseT != null)
{
currentBody.Clauses.From(fromClauseT.RangeVariableInfo, fromClauseT.RangeSource);
continue;
}
var fromClause = pathNodes[i] as LinqFromBodyBuilder;
if (fromClause != null)
{
currentBody.Clauses.From(fromClause.RangeVariableName, fromClause.RangeSource);
continue;
}
var joinClauseT = pathNodes[i] as LinqTypedJoinBodyBuilder;
if (joinClauseT != null)
{
currentBody.Clauses.Join(joinClauseT.RangeVariableInfo, joinClauseT.RangeSource, joinClauseT.LeftConditionSelector, joinClauseT.RightConditionSelector, joinClauseT.IntoTarget);
continue;
}
var joinClause = pathNodes[i] as LinqJoinBodyBuilder;
if (joinClause != null)
{
currentBody.Clauses.Join(joinClause.RangeVariableName, joinClause.RangeSource, joinClause.LeftConditionSelector, joinClause.RightConditionSelector, joinClause.IntoTarget);
continue;
}
var letClause = pathNodes[i] as LinqLetBodyBuilder;
if (letClause != null)
{
currentBody.Clauses.Let(letClause.RangeVariableName, letClause.RangeSource);
continue;
}
var dOrderClause = pathNodes[i] as LinqDirectedOrderByBodyBuilder;
if (dOrderClause != null)
{
/* *
* Special case, forward glance needs made to determine the proper
* clause to construct.
* */
int lastClause = -1;
for (int j = i + 1; j < pathNodes.Length; j++)
{
if (pathNodes[j] is LinqThenByBodyBuilder ||
pathNodes[j] is LinqDirectedThenByBodyBuilder)
{
lastClause = j;
}
else
{
break;
}
}
if (lastClause == -1)
{
currentBody.Clauses.OrderBy(dOrderClause.OrderKey, dOrderClause.Direction);
}
else
{
var pairs = new LinqOrderingPair[(lastClause + 1) - i];
pairs[0] = new LinqOrderingPair(dOrderClause.OrderKey, dOrderClause.Direction);
int lastValid = i;
for (int j = i + 1; j <= lastClause; j++)
{
var dThenBy = pathNodes[j] as LinqDirectedThenByBodyBuilder;
if (dThenBy != null)
{
pairs[j - i] = new LinqOrderingPair(dThenBy.OrderKey, dThenBy.Direction);
lastValid = j;
continue;
}
var thenBy = pathNodes[j] as LinqThenByBodyBuilder;
if (thenBy != null)
{
pairs[j - i] = new LinqOrderingPair(thenBy.OrderKey);
lastValid = j;
continue;
}
break;
}
i = lastValid;
currentBody.Clauses.OrderBy(pairs);
}
continue;
}
var orderClause = pathNodes[i] as LinqOrderByBodyBuilder;
if (orderClause != null)
{
int lastClause = -1;
for (int j = i + 1; j < pathNodes.Length; j++)
{
if (pathNodes[j] is LinqThenByBodyBuilder ||
pathNodes[j] is LinqDirectedThenByBodyBuilder)
{
lastClause = j;
}
else
{
break;
}
}
if (lastClause == -1)
{
currentBody.Clauses.OrderBy(orderClause.OrderKey);
}
else
{
var pairs = new LinqOrderingPair[(lastClause + 1) - i];
pairs[0] = new LinqOrderingPair(orderClause.OrderKey);
int lastValid = i;
for (int j = i + 1; j <= lastClause; j++)
{
var dThenBy = pathNodes[j] as LinqDirectedThenByBodyBuilder;
if (dThenBy != null)
{
pairs[j - i] = new LinqOrderingPair(dThenBy.OrderKey, dThenBy.Direction);
lastValid = j;
continue;
}
var thenBy = pathNodes[j] as LinqThenByBodyBuilder;
if (thenBy != null)
{
pairs[j - i] = new LinqOrderingPair(thenBy.OrderKey);
lastValid = j;
continue;
}
break;
}
i = lastValid;
currentBody.Clauses.OrderBy(pairs);
}
continue;
}
var whereClause = pathNodes[i] as LinqWhereBodyBuilder;
if (whereClause != null)
{
currentBody.Clauses.Where(whereClause.BooleanCondition);
continue;
}
var groupBuilder = pathNodes[i] as LinqTailGroupBodyBuilder;
LinqTailSelectBodyBuilder selectBuilder;
/* *
* If we're working with a group builder...
* */
if (groupBuilder != null)
{
var gbCurrent = currentBody as ILinqGroupBody;
if (gbCurrent == null)
{
break;
}
/* *
* No continuation, we're finished.
* */
if (last)
{
gbCurrent.Key = groupBuilder.Key;
gbCurrent.Selection = groupBuilder.Selection;
break;
}
else
{
/* *
* Link the current to the next, and set its
* target 'into' range variable name.
* */
var gfbCurrent = gbCurrent as ILinqFusionGroupBody;
if (gfbCurrent == null)
{
break;
}
gfbCurrent.Key = groupBuilder.Key;
gfbCurrent.Selection = groupBuilder.Selection;
var next = pathNodes[++i] as LinqFusionBodyBuilder;
if (next == null)
{
break;
}
gfbCurrent.Target.Name = next.IntoRangeName;
gfbCurrent.Next = currentBody = GetBody(bodyTypes[bodyIndex++]);
}
}
else if ((selectBuilder = pathNodes[i] as LinqTailSelectBodyBuilder) != null)
{
var sbCurrent = currentBody as ILinqSelectBody;
if (sbCurrent == null)
{
break;
}
/* *
* No continuation, we're finished.
* */
if (last)
{
sbCurrent.Selection = selectBuilder.Selection;
break;
}
else
{
/* *
* Link the current to the next, and set its
* target 'into' range variable name.
* */
var sfbCurrent = sbCurrent as ILinqFusionSelectBody;
if (sfbCurrent == null)
{
break;
}
sfbCurrent.Selection = selectBuilder.Selection;
var next = pathNodes[++i] as LinqFusionBodyBuilder;
if (next == null)
{
break;
}
sfbCurrent.Target.Name = next.IntoRangeName;
sfbCurrent.Next = currentBody = GetBody(bodyTypes[bodyIndex++]);
}
}
}
return(result);
}