public Estimator <TTupleInShape, TTupleNewOutShape, ITransformer> Append <[IsShape] TTupleNewOutShape>(Func <TTupleOutShape, TTupleNewOutShape> mapper)
{
Contracts.CheckValue(mapper, nameof(mapper));
using (var ch = Env.Start(nameof(Append)))
{
var method = mapper.Method;
// Construct the dummy column structure, then apply the mapping.
var input = StaticPipeInternalUtils.MakeAnalysisInstance <TTupleOutShape>(out var fakeReconciler);
KeyValuePair <string, PipelineColumn>[] inPairs = StaticPipeInternalUtils.GetNamesValues(input, method.GetParameters()[0]);
// Initially we suppose we've only assigned names to the inputs.
var inputColToName = new Dictionary <PipelineColumn, string>();
foreach (var p in inPairs)
{
inputColToName[p.Value] = p.Key;
}
string NameMap(PipelineColumn col)
{
inputColToName.TryGetValue(col, out var val);
return(val);
}
var readerEst = StaticPipeUtils.GeneralFunctionAnalyzer(Env, ch, input, fakeReconciler, mapper, out var estTail, NameMap);
ch.Assert(readerEst == null);
ch.AssertValue(estTail);
var est = AsDynamic.Append(estTail);
var newOut = StaticSchemaShape.Make <TTupleNewOutShape>(method.ReturnParameter);
var toReturn = new Estimator <TTupleInShape, TTupleNewOutShape, ITransformer>(Env, est, _inShape, newOut);
ch.Done();
return(toReturn);
}
}
