composition

I have a AggregateCatalog that contains an AssemblyCatalog and a DirectoryCatalog. I want them to work like this: If both catalogs can find an export, choose the one from the DirectoryCatalog. If neither of them can find an export, then just leave the import to be null. If only one of them can find an export, then just use that export to fill the import. How can I achieve something like this? You can achieve point 1. and 3. by putting the catalogs in different export providers, and then passing the export providers to the CompositionContainer constructor in order of priority like this: var

Scala functions has following methods for chaining: fn1.andThen(fn2) fn1.compose(fn2) But how can be written this case: I have function cleanUp() which has to be called always as last step. And I have a bunch of other functions, like that: class Helper { private[this] val umsHelper = new UmsHelper() private[this] val user = umsHelper.createUser() def cleanUp = ... // delete user/ and other entities def prepareModel(model: TestModel) = { // create model on behalf of the user } def commitModel() = { // commit model on behalf of the user } } And some external code can use code something like this

I have a few (fairly redundant) queries in my app that are something like this: var last30Days = DateTime.Today.AddDays(-30); from b in Building let issueSeverity = (from u in Users where u.Building == b from i in u.Issues where i.Date > last30Days select i.Severity).Max() select new { Building = b, IssueSeverity = issueSeverity } And: var last30Days = DateTime.Today.AddDays(-30); from c in Countries let issueSeverity = (from u in Users where u.Building.Country == c from i in u.Issues where i.Date > last30Days select i.Severity).Max() select new { Country = c, IssueSeverity = issueSeverity }

I've got a problem with Java concurrency. Yes, I looked at questions with almost the exact same title, but they all seemed to be asking subtly different things. Yes, I've read Java Concurrency in Practice . Yes, I can see why it's the defacto reference for the topic. Yes, I've read the section specifically on publishing fields in thread-safe classes. Yes, I'm still going to ask a concurrency question on Java regardless of the fact that I know someone will simply point me to that book. This has me stumped though -- I know that you can easily publish mutable primitive fields in a thread-safe

I am currently trying to optimize my Python program and got started with Cython in order to reduce the function calling overhead and perhaps later on include optimized C-libraries functions. So I ran into the first problem: I am using composition in my code to create a larger class. So far I have gotten one of my Python classes converted to Cython (which was difficult enough). Here's the code: import numpy as np cimport numpy as np ctypedef np.float64_t dtype_t ctypedef np.complex128_t cplxtype_t ctypedef Py_ssize_t index_t cdef class bendingForcesClass(object): cdef dtype_t bendingRigidity

What is the right way to create a function that can dynamically create composed map? This results in an error (also happens with fmap): createComposedMaps list = accumulate list map where accumulate (x:xs) m = accumulate xs (m.map) accumulate [] m = m The list is irrelevant, it's just there to count the number of compositions. The error I get back is about "cannot construct infinite type": Occurs check: cannot construct the infinite type: a2 ~ [a2] Expected type: (a2 -> b1) -> a2 -> b1 Actual type: (a2 -> b1) -> [a2] -> [b1] Relevant bindings include m :: (a2 -> b1) -> c (bound at dimensional

Please let me know what is the best way to determine composition of young generation memory promoted to old generation, after each young GC event? Ideally I would like to know class names which are responsible say, for 80% of heap in each "young gen -> old gen" promotion chunk; Example: I have 600M young gen, each tenure promotes 6M; I want to know which objects compose this 6M. Thank you. JT. There is no easy way to do this, however, I have recently been analyzing memory performance of large java apps, and can share some experience. Here is how I found what objects are being promoted to old