public override IObservable <TSource> Process <TSource>(IObservable <TSource> source)
{
return(Observable.Defer(() =>
{
var engine = PythonEngine.Create();
var scope = engine.CreateScope();
engine.Execute(Script, scope);
object condition;
PythonProcessor <TSource, bool> processor;
if (PythonHelper.TryGetClass(scope, "Condition", out condition))
{
processor = new PythonProcessor <TSource, bool>(engine.Operations, condition);
}
else
{
processor = new PythonProcessor <TSource, bool>(scope);
}
if (processor.Load != null)
{
processor.Load();
}
var result = source.Where(processor.Process);
if (processor.Unload != null)
{
result = result.Finally(processor.Unload);
}
return result;
}));
}
public override Expression Build(IEnumerable <Expression> arguments)
{
var engine = PythonEngine.Create();
var scope = engine.CreateScope();
var script = PythonHelper.ReturnsDecorator + Script;
var scriptSource = engine.CreateScriptSourceFromString(script);
scriptSource.Execute(scope);
var scopeExpression = Expression.Constant(scope);
var outputType = PythonHelper.GetOutputType(scope, PythonHelper.GenerateFunction);
var generatorType = Expression.GetFuncType(typeof(PythonGenerator));
var generateExpression = Expression.Call(
scopeExpression,
"GetVariable",
new[] { generatorType },
Expression.Constant(PythonHelper.GenerateFunction));
var combinatorExpression = Expression.Constant(this);
return(Expression.Call(combinatorExpression, "Generate", new[] { outputType }, generateExpression));
}
public override Expression Build(IEnumerable <Expression> arguments)
{
var engine = PythonEngine.Create();
var scope = engine.CreateScope();
var script = PythonHelper.ReturnsDecorator + Script;
var scriptSource = engine.CreateScriptSourceFromString(script);
scriptSource.Execute(scope);
object selectMany;
var source = arguments.Single();
var observableType = source.Type.GetGenericArguments()[0];
if (PythonHelper.TryGetClass(scope, "SelectMany", out selectMany))
{
var classExpression = Expression.Constant(selectMany);
var opExpression = Expression.Constant(engine.Operations);
var outputType = PythonHelper.GetOutputType(engine.Operations, selectMany, PythonHelper.ProcessFunction);
return(Expression.Call(
typeof(PythonTransform),
"Process",
new[] { observableType, outputType },
source,
opExpression,
classExpression));
}
else
{
var outputType = PythonHelper.GetOutputType(scope, PythonHelper.ProcessFunction);
var scopeExpression = Expression.Constant(scope);
return(Expression.Call(
typeof(PythonSelectMany),
"Process",
new[] { observableType, outputType },
source,
scopeExpression));
}
}
protected virtual ScriptEngine CreateEngine()
{
return(PythonEngine.Create());
}