/// <summary>
/// Initializes the expression from the list of clauses.
/// </summary>
/// <param name="items">
/// The list of clauses in the expression.
/// </param>
private void InitializeFromClauses(IEnumerable <QueryClause> items)
{
Param.AssertNotNull(items, "items");
foreach (QueryClause clause in items)
{
foreach (Expression expression in clause.ChildExpressions)
{
this.AddExpression(expression);
}
QueryContinuationClause continuationClause = clause as QueryContinuationClause;
if (continuationClause != null)
{
this.InitializeFromClauses(continuationClause.ChildClauses);
}
}
}
/// <summary>
/// Walks the children of the given query clause.
/// </summary>
/// <param name="clause">
/// The clause.
/// </param>
/// <param name="parentClause">
/// The parent clause, if any.
/// </param>
/// <param name="parentExpression">
/// The parent expression, if any.
/// </param>
/// <param name="parentStatement">
/// The parent statement, if any.
/// </param>
/// <param name="parentElement">
/// The parent element, if any.
/// </param>
/// <param name="context">
/// The optional visitor context data.
/// </param>
/// <returns>
/// Returns true to continue, or false to stop the walker.
/// </returns>
private bool WalkQueryClause(
QueryClause clause, QueryClause parentClause, Expression parentExpression, Statement parentStatement, CsElement parentElement, T context)
{
Param.Ignore(clause, parentClause, parentExpression, parentStatement, parentElement, context);
if (clause != null)
{
T childContext = context;
if (!this.VisitQueryClause(clause, parentClause, parentExpression, parentStatement, parentElement, ref childContext))
{
return(false);
}
foreach (Expression childExpression in clause.ChildExpressions)
{
if (!this.WalkExpression(childExpression, parentExpression, parentStatement, parentElement, childContext))
{
return(false);
}
}
if (clause.QueryClauseType == QueryClauseType.Continuation)
{
QueryContinuationClause continuationClause = (QueryContinuationClause)clause;
foreach (QueryClause childClause in continuationClause.ChildClauses)
{
if (!this.WalkQueryClause(childClause, clause, parentExpression, parentStatement, parentElement, childContext))
{
return(false);
}
}
}
}
return(true);
}
/// <summary>
/// Gets a query continuation clause.
/// </summary>
/// <param name="parentReference">
/// The parent code unit.
/// </param>
/// <param name="unsafeCode">
/// Indicates whether the code being parsed resides
/// in an unsafe code block.
/// </param>
/// <returns>
/// Returns the query continuation clause.
/// </returns>
private QueryContinuationClause GetQueryContinuationClause(Reference<ICodePart> parentReference, bool unsafeCode)
{
Param.AssertNotNull(parentReference, "parentReference");
Param.Ignore(unsafeCode);
// Get and add the 'into' symbol.
Symbol symbol = this.GetNextSymbol(SymbolType.Other, parentReference);
Debug.Assert(symbol.Text == "into", "Expected an into keyword");
Reference<ICodePart> clauseReference = new Reference<ICodePart>();
Node<CsToken> firstTokenNode = this.tokens.InsertLast(this.GetToken(CsTokenType.Into, SymbolType.Other, clauseReference));
// Get the identifier.
Variable rangeVariable = this.GetVariable(clauseReference, unsafeCode, true, true);
if (rangeVariable == null)
{
throw this.CreateSyntaxException();
}
// Get the continuation clauses.
List<QueryClause> clauses = new List<QueryClause>();
// The variables defined by the clauses under this continuation clause.
List<Variable> variables = new List<Variable>();
// Extract the clauses.
CsTokenList continuationClauseTokens = this.GetQueryExpressionClauses(clauseReference, unsafeCode, clauses, variables);
if (clauses.Count == 0 || continuationClauseTokens.First == null)
{
throw this.CreateSyntaxException();
}
// Create and return the clause.
QueryContinuationClause continuationClause = new QueryContinuationClause(
new CsTokenList(this.tokens, firstTokenNode, continuationClauseTokens.Last), rangeVariable, clauses.ToArray());
clauseReference.Target = continuationClause;
continuationClause.Variables.AddRange(variables);
return continuationClause;
}
/// <summary>
/// Analyzes the given query clauses.
/// </summary>
/// <param name="element">
/// The element containing the clauses.
/// </param>
/// <param name="expression">
/// The expression containing the clauses.
/// </param>
/// <param name="clauses">
/// The list of clauses to analyze.
/// </param>
/// <param name="previousClause">
/// The previous clause in the expression, if any.
/// </param>
/// <param name="clauseOnSameLine">
/// Indicates whether any clause has been seen previously which
/// starts on the same line as the clause before it.
/// </param>
/// <param name="clauseOnSeparateLine">
/// Indicates whether any clause has been seen previously which
/// starts on the line after the clause before it.
/// </param>
/// <returns>
/// Returns true to continue checking the query clause, or false to quit.
/// </returns>
private bool ProcessQueryClauses(
CsElement element,
QueryExpression expression,
ICollection <QueryClause> clauses,
ref QueryClause previousClause,
ref bool clauseOnSameLine,
ref bool clauseOnSeparateLine)
{
Param.AssertNotNull(element, "element");
Param.AssertNotNull(expression, "expression");
Param.AssertNotNull(clauses, "clauses");
Param.Ignore(previousClause);
Param.Ignore(clauseOnSameLine);
Param.Ignore(clauseOnSeparateLine);
foreach (QueryClause clause in clauses)
{
if (previousClause != null)
{
// Figure out the line number that the previous clause ends on. For most
// clauses, this is simply the end point of the clause location property,
// but for continuation clauses we want to use the location of the 'into' variable,
// which conceptually represents the end of the continuation line.
int previousClauseEndLineNumber = previousClause.Location.EndPoint.LineNumber;
if (previousClause.QueryClauseType == QueryClauseType.Continuation)
{
previousClauseEndLineNumber = ((QueryContinuationClause)previousClause).Variable.Location.LineNumber;
}
// Ensure that the clause either starts on the same line as the expression, or
// on the very next line.
if (clause.LineNumber == previousClauseEndLineNumber)
{
// This is only ok if the previous clause does not span multiple lines.
if (previousClause.Location.LineSpan > 1)
{
this.AddViolation(element, clause.LineNumber, Rules.QueryClauseMustBeginOnNewLineWhenPreviousClauseSpansMultipleLines);
return(false);
}
// The rest of the checks are only applied when the clause is not a query continuation clause. A continuation
// clause is allowed to begin at the end of the previous clause, on the same line.
if (clause.QueryClauseType != QueryClauseType.Continuation)
{
// The clause starts on the same line as the ending of the previous clause.
// This is ok as long as we have not previously seen a clause which starts
// on its own line. The one exception is that query continuation clauses
// are allowed to be inserted at the end of the previous claus.
if (clauseOnSeparateLine)
{
this.AddViolation(element, clause.LineNumber, Rules.QueryClausesMustBeOnSeparateLinesOrAllOnOneLine);
return(false);
}
// If the clause spans multiple lines, it must begin on its own line. The exception is query continuation
// clauses, which are allowed to begin at the end of the previous claus.
if (clause.Location.LineSpan > 1)
{
this.AddViolation(element, clause.LineNumber, Rules.QueryClausesSpanningMultipleLinesMustBeginOnOwnLine);
return(false);
}
// Indicate that we have seen a clause which starts on the same line as the
// previous clause.
clauseOnSameLine = true;
}
}
else if (clause.LineNumber == previousClauseEndLineNumber + 1)
{
// The clause starts on the line just after the previous clause.
// This is fine unless we have previously seen two clauses on the same line.
if (clauseOnSameLine)
{
this.AddViolation(element, clause.LineNumber, Rules.QueryClausesMustBeOnSeparateLinesOrAllOnOneLine);
return(false);
}
// Indicate that we have seen a clause which begins on the line after
// the previous clause.
clauseOnSeparateLine = true;
}
else if (clause.LineNumber > previousClauseEndLineNumber + 1)
{
// The clause does not start on the line after the previous clause.
this.AddViolation(element, clause.LineNumber, Rules.QueryClauseMustFollowPreviousClause);
return(false);
}
}
previousClause = clause;
if (clause.QueryClauseType == QueryClauseType.Continuation)
{
QueryContinuationClause continuationClause = (QueryContinuationClause)clause;
if (
!this.ProcessQueryClauses(
element, expression, continuationClause.ChildClauses, ref previousClause, ref clauseOnSameLine, ref clauseOnSeparateLine))
{
return(false);
}
}
}
return(true);
}
