Delimited continuations manipulate the control flow of programs. Similar to control structures like conditionals or loops they allow to deviate from a sequential flow of control.
We use exception handling as another example for control flow manipulation and later show how to implement it using delimited continuations. Finally, we show that nondeterminism can also be expressed using delimited continuations.
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| { Project JEDI Code Library (JCL) } | |
| { } | |
| { The contents of this file are subject to the Mozilla Public License Version 1.1 (the "License"); } | |
| { you may not use this file except in compliance with the License. You may obtain a copy of the } | |
| { License at http://www.mozilla.org/MPL/ } | |
| { } | |
| { Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF } | |
| { ANY KIND, either express or implied. See the License for the specific language governing rights } |
| /* open up chrome dev tools (Menu > More tools > Developer tools) | |
| * go to network tab, refresh the page, wait for images to load (on some sites you may have to scroll down to the images for them to start loading) | |
| * right click/ctrl click on any entry in the network log, select Copy > Copy All as HAR | |
| * open up JS console and enter: var har = [paste] | |
| * (pasting could take a while if there's a lot of requests) | |
| * paste the following JS code into the console | |
| * copy the output, paste into a text file | |
| * open up a terminal in same directory as text file, then: wget -i [that file] | |
| */ |
| { | |
| The idea of DelphiSwitchToFiber() function is to backup on a local variable in stack the | |
| state of the Exception stack right before calling SwitchToFiber() and then restoring its state | |
| right atfer returns from call to SwitchToFiber(). | |
| If SwitchToFiber() is used directly from within an Except or Finally block, and if there's an exception | |
| raised after switching to another fiber, upon coming back the results will be unpredictable because | |
| the exception stack will be completely unwinded and all raise exceptions destroyed. | |
| In order to prevent this issue we must backup the Exception stack before the call to SwitchToFiber() | |
| and restore it right after the call. |
| Okay, so I'll try and walk through the reader monad as best as I can. And | |
| because I think it helps to de-mystify things a bit, I'll also go through | |
| all of the "super classes" of monad: functor and applicative (because every | |
| monad should also be an applicative and every applicative functor should be | |
| a functor). This file is literate Haskell so you should just be able to | |
| load it in the REPL or run it. It's also kinda/sorta markdown, so it should | |
| render that way as well (but the code is formatted wrong). | |
| > module Reader where |
| #include <iostream> | |
| #include <chrono> | |
| #include <ctime> | |
| #include <cmath> | |
| class Timer | |
| { | |
| public: | |
| void start() | |
| { |
| /* | |
| * Coroutines. | |
| * | |
| * To make a (fake) coroutine we use these macros. A coroutine method must be static, | |
| * return bool and needs a parameter (Generator & generator). | |
| * | |
| * Generator must follow this schema: | |
| * struct Generator { | |
| * int line; | |
| * float time; |
| procedure LoadImageFromDbToTImage(img: TImage; Field: string; id: integer); | |
| var | |
| memStream: TMemoryStream; | |
| Graphic: Graphics.TGraphic; | |
| bm: Graphics.Tbitmap; | |
| begin | |
| odsImages.Close; | |
| odsImages.SetVariable('id', id); //ИД картинки | |
| odsImages.Open; |
What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.
In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.
Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th
