Comments (4)
All of the itertools have InputIterator
s for the sake of it being doable. You can't reverse something with input iterators without constructing a temporary container to hold the contents, but then you lose the lazy evaluation.
Supporting reverse would mean supporting types that may have rend()
and rbegin()
themselves, or only extending the iterator capabilities in the case of the underlying sequence (container1
, etc) having a more flexible iterator type. The work involved here is huge, I don't have any plans to implement this right now.
If your two containers are of equal length and are themselves reversible, I think you could get away with
zip(reversed(container1), reversed(container2))
from cppitertools.
Thank you for your quick answer! The code you proposed works in my situation.
I will have a look if I can find a general solution involving rend() and rbegin() but I have little experience in heavy template usage.
from cppitertools.
it's pretty heavy. The SFINAEing involved will need to be pretty precise if I'm picturing this correctly. Reversing is also non-obvious for many itertools. For example, consider the case where container1
and container2
have different lengths:
std::vector<int> v = {1, 2, 3};
std::string s{"abcdef"};
If you zip this zip(v, s)
you'll get
{1, a}
{2, b}
{3, c}
If you reverse it reversed(zip(v,s))
, what should you get? The reversed version of the above would be
{3, c}
{2, b}
{1, a}
but that doesn't match zip(reversed(v), reversed(s))
:
{3, f}
{2, e}
{1, d}
from cppitertools.
I think in case of containers of different length it would be ok if the two versions with reversed() differ, as long as the rules of how they work/differ are clear.
I realized I won't have the time to work on an implementation right now and my problem has been solved, so I will close this issue. Thanks for your help!
from cppitertools.
Related Issues (20)
- Can't get cmake FetchContent to work HOT 12
- iter::combinations' behaviour when r = 0 is different from Python's itertools.combinations HOT 2
- Question: calling functions with iterators as parameters HOT 2
- Internal linkage of iter::chain leads to ODR violation. HOT 1
- Unable to use iterator from combination with C++17 STL transform_reduce HOT 1
- product's repeat argument as a variant.
- enumerate.hpp mixes class and struct HOT 1
- enumerate with signed index HOT 2
- [DOC] compress HOT 2
- Requesting rbegin and rend for iter::repeat HOT 5
- Fix all `reference` type aliases to match the return type of operator* exactly.
- Accept move-only callables in all itertools that take callables objects
- unique_everseen should be templated by a hash function and use a different set object HOT 1
- dereference operators should be const
- Add security policy
- Can't use as subproject HOT 3
- Nesting with Combinations Compilation Issue in MSVC HOT 1
- [cmake] FetchContent warning message HOT 1
- Question : enumerate(zip(...)) HOT 4
- Combinations seems not to work with std::vector<torch::Tensor> with degree 3. HOT 2
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from cppitertools.