Expression ParseAtom()
{
string id;
Expression x = null;
FunctionDefinition fnDef = null;
switch (_token.Type)
{
// literals
case TKTYPE.LITERAL:
x = new Expression(_token);
break;
// identifiers
case TKTYPE.IDENTIFIER:
// get identifier
id = (string)_token.Value;
// look for functions
if (_fnTbl.TryGetValue(id, out fnDef))
{
var p = GetParameters();
var pCnt = p == null ? 0 : p.Count;
if (fnDef.ParmMin != -1 && pCnt < fnDef.ParmMin)
{
Throw("Too few parameters.");
}
if (fnDef.ParmMax != -1 && pCnt > fnDef.ParmMax)
{
Throw("Too many parameters.");
}
x = new FunctionExpression(fnDef, p);
break;
}
// look for simple variables (much faster than binding!)
if (_vars.ContainsKey(id))
{
x = new VariableExpression(_vars, id);
break;
}
// look for external objects
var xObj = GetExternalObject(id);
if (xObj != null)
{
x = new XObjectExpression(xObj);
break;
}
// look for bindings
if (DataContext != null)
{
var list = new List <BindingInfo>();
for (var t = _token; t != null; t = GetMember())
{
list.Add(new BindingInfo((string)t.Value, GetParameters()));
}
x = new BindingExpression(this, list, _ci);
break;
}
Throw("Unexpected identifier");
break;
// sub-expressions
case TKTYPE.GROUP:
// anything other than opening parenthesis is illegal here
if (_token.ID != TKID.OPEN)
{
Throw("Expression expected.");
}
// get expression
GetToken();
x = ParseCompare();
// check that the parenthesis was closed
if (_token.ID != TKID.CLOSE)
{
Throw("Unbalanced parenthesis.");
}
break;
}
// make sure we got something...
if (x == null)
{
Throw();
}
// done
GetToken();
return(x);
}
void _observer_OnPostEvaluate(object sender, EvaluateEventArgs e)
{
if (_maxLevel >= 0 && _DependencyDepth > _maxLevel)
{
return;
}
if (_suppressLevel >= 0 && _DependencyDepth >= _suppressLevel)
{
return;
}
if (e.Expression._token.Type == TKTYPE.LITERAL)
{
return;
}
if (e.Expression._token.ID == TKID.SUPPRESS)
{
return;
}
if (e.Expression is VariableExpression)
{
if (!this.AuditVariables)
{
return;
}
var v = e.Expression as VariableExpression;
if ((v.Variable != null) && !v.Variable.CreateAudit)
{
return;
}
}
if (e.Expression is FunctionExpression)
{
FunctionExpression func = e.Expression as FunctionExpression;
if (!func._fn.Audited)
{
return;
}
}
StringBuilder auditBuilder = new StringBuilder();
auditBuilder.Append(e.Expression.ToString());
auditBuilder.Append(" = ");
if (e.Value != null)
{
if (e.Value is IEnumerable)
{
Expression.BuildParameterList(auditBuilder, e.Value as IEnumerable, sb => sb.AppendLine(","));
}
else
{
auditBuilder.Append(e.Value.ToString());
}
}
auditBuilder.AppendLine();
string auditText = auditBuilder.ToString();
if (_auditHashes.Add(auditText))
{
_stringBuilder.Append(auditText);
}
}