/// <summary>
/// Performs all expression subsitutions known by the code context on the input. It does not
/// touch the input - but returns a new IValue. Types are not tracked.
/// </summary>
/// <param name="input"></param>
/// <param name="cc"></param>
/// <returns></returns>
/// <remarks>
/// This exists because sometimes you need to do this sort of replacement when dealing with complex
/// expressions that don't translated to C# easily. In partiuclar, for example, the iterator expressions
/// that are used to move through maps in the Group By operators. Otherwise, the regular GetExpression would
/// do this just fine.
/// </remarks>
public static IValue PerformAllSubstitutions(this IValue input, ICodeContext cc)
{
var vFinder = new Regex(@"\b(?<vname>[\w]*)\b");
string v = input.RawValue;
bool subDone = true;
int count = 0;
while (subDone)
{
count++;
if (count > 100)
{
throw new InvalidOperationException(string.Format("Unable to translate '{0}' due to too many sutstitutions.", input.RawValue));
}
subDone = false;
foreach (Match match in vFinder.Matches(v))
{
var vname = match.Groups["vname"].Value;
var r = cc.GetReplacement(vname);
if (r != null)
{
v = Regex.Replace(v, string.Format(@"\b{0}\b", vname), r.ParameterName());
subDone = true;
}
}
}
if (count == 1)
{
return(input);
}
return(new ValSimple(v, input.Type, input.Dependants));
}
/// <summary>
/// Turn a query model into code.
/// </summary>
/// <param name="queryModel"></param>
private void VisitQueryModelNoCache(QueryModel queryModel)
{
// Cache the referenced query expressions and restore them at the end.
var cachedReferencedQS = _codeContext.GetAndResetQuerySourceLookups();
// Protect against all returns...
try
{
//
// If the query model is something that is trivial, then
// perhaps there is a short-cut we can take?
//
if (queryModel.IsIdentityQuery() && queryModel.ResultOperators.Count == 1)
{
var ro = queryModel.ResultOperators[0];
var processor = _operators.FindScalarROProcessor(ro.GetType());
if (processor != null)
{
var result = processor.ProcessIdentityQuery(ro, queryModel, _codeEnv, _codeContext, MEFContainer);
if (result != null &&
result.Item1)
{
Debug.WriteLine("Identity Query being processed");
_codeEnv.SetResult(result.Item2);
return;
}
}
}
// Have we seen this query model before? If so, perhaps we can just short-circuit this?
var cachedResult = _codeContext.GetReplacement(queryModel);
if (cachedResult != null)
{
var context = _codeEnv.FirstAllInScopeFromNow(FindDeclarableParameters.FindAll(cachedResult));
if (context != null)
{
_codeEnv.SetResult(cachedResult);
return;
}
}
// If we drop through here, then let the full machinery parse the thing
base.VisitQueryModel(queryModel);
}
finally
{
_codeContext.RestoreQuerySourceLookups(cachedReferencedQS);
}
}
/// <summary>
/// Performs all expression subsitutions known by the code context on the input. It does not
/// touch the input - but returns a new IValue. Types are not tracked.
/// </summary>
/// <param name="input"></param>
/// <param name="cc"></param>
/// <returns></returns>
/// <remarks>
/// This exists because sometimes you need to do this sort of replacement when dealing with complex
/// expressions that don't translated to C# easily. In partiuclar, for example, the iterator expressions
/// that are used to move through maps in the Group By operators. Otherwise, the regular GetExpression would
/// do this just fine.
/// </remarks>
public static IValue PerformAllSubstitutions(this IValue input, ICodeContext cc)
{
var vFinder = new Regex(@"\b(?<vname>[\w]*)\b");
string v = input.RawValue;
bool subDone = true;
int count = 0;
while (subDone)
{
count++;
if (count > 100)
throw new InvalidOperationException(string.Format("Unable to translate '{0}' due to too many sutstitutions.", input.RawValue));
subDone = false;
foreach (Match match in vFinder.Matches(v))
{
var vname = match.Groups["vname"].Value;
var r = cc.GetReplacement(vname);
if (r != null)
{
v = Regex.Replace(v, string.Format(@"\b{0}\b", vname), r.ParameterName());
subDone = true;
}
}
}
if (count == 1)
return input;
return new ValSimple(v, input.Type, input.Dependants);
}
/// <summary>
/// Do the lookup for the expression, and recursivly resolve it, incease there are further
/// parameters in it.
/// </summary>
/// <param name="exprName"></param>
/// <returns></returns>
private Expression ResolveExpressionReplacement(string exprName)
{
var replaceit = _context.GetReplacement(exprName);
return(Visit(replaceit));
}
