// Common entry point for executing code
public TypedValue Exec(ByteCode code, ILookupValue lookup = null, TypedValue aggregate = null, AccumulatorBlock accblock = null)
{
Logger.WriteLine(5, "Exec {0} {1} {2} {3}", code.Length, lookup, aggregate, accblock);
if (code.Length == 0)
{
return(VoidValue.Void);
}
if (lookup != null)
{
PushLookup(lookup);
}
//Current = this;
TypedValue retval = null;
try {
retval = Run(code, aggregate, accblock);
} catch (TargetInvocationException ex) {
Logger.WriteLine(3, "Exception {0}", ex.ToString());
throw ex.InnerException;
}
if (lookup != null)
{
PopLookup();
}
return(retval);
}
// evaluate an open expression returning a typed value
// rename -- do it here
// aggregate -- not safe to eval, so just return typed default
public TypedValue EvalOpen(ILookupValue lookup)
{
if (IsValue)
{
return(Value);
}
if (HasFold)
{
return(ReturnType.DefaultValue());
}
TypedValue ret;
if (IsRename || IsProject)
{
ret = Evaluator.Lookup(OldName, lookup);
}
else
{
Logger.Assert(IsOpen || HasWin || lookup == null, Name);
Logger.Assert(Evaluator != null, "evaluator null");
ret = Evaluator.Exec(Code, lookup);
}
CheckReturnType(ret);
return(ret);
}
// evaluate a fold expression with previous value returning an updated value
public TypedValue EvalIsFolded(ILookupValue lookup, TypedValue aggregate)
{
Logger.Assert(IsFolded, Name);
var ret = Evaluator.Exec(Code, lookup, aggregate);
CheckReturnType(ret);
return(ret);
}
// evaluate a post-fold expression that depends on accumulator values
public TypedValue EvalHasFold(ILookupValue lookup, AccumulatorBlock accblock, int accbase = 0)
{
Logger.Assert(HasFold, Name);
accblock.IndexBase = accbase;
var ret = Evaluator.Exec(Code, lookup, null, accblock);
CheckReturnType(ret);
return(ret);
}
// evaluate an open predicate expression returning true/false
public BoolValue EvalPred(ILookupValue lookup)
{
Logger.Assert(ReturnType == DataTypes.Bool, Name);
if (Code.Length == 0)
{
return(BoolValue.True);
}
return(EvalOpen(lookup) as BoolValue);
}
// Convert using lookup as context. Used by Invoke.
public static DataTableLocal Convert(DataTable other, ILookupValue lookup, Evaluator evaluator)
{
if (other is DataTableLocal)
{
return(other as DataTableLocal);
}
else
{
evaluator.PushLookup(lookup);
var ret = Create(other.Heading, other.GetRows());
evaluator.PopLookup();
return(ret);
}
}
// Perform a value lookup for project
public TypedValue Lookup(string name, ILookupValue lookup = null)
{
if (lookup != null)
{
_lookups.Push(lookup);
}
var value = TypedValue.Empty;
var ok = LookupValue(name, ref value);
Logger.Assert(ok, name);
if (lookup != null)
{
_lookups.Pop();
}
return(value);
}
// used by Invoke
public void PushLookup(ILookupValue lookup)
{
Logger.WriteLine(4, "Push lookup {0}", lookup);
_lookups.Push(lookup);
}