Hopscotch map
PEGTL
Our great sponsors
Hopscotch map | PEGTL | |
---|---|---|
3 | 11 | |
630 | 1,710 | |
- | 0.9% | |
0.0 | 5.3 | |
6 days ago | 8 days ago | |
C++ | C++ | |
MIT License | Boost Software License 1.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Hopscotch map
-
boost::unordered map is a new king of data structures
Unordered hash map shootout CMAP = https://github.com/tylov/STC KMAP = https://github.com/attractivechaos/klib PMAP = https://github.com/greg7mdp/parallel-hashmap FMAP = https://github.com/skarupke/flat_hash_map RMAP = https://github.com/martinus/robin-hood-hashing HMAP = https://github.com/Tessil/hopscotch-map TMAP = https://github.com/Tessil/robin-map UMAP = std::unordered_map Usage: shootout [n-million=40 key-bits=25] Random keys are in range [0, 2^25). Seed = 1656617916: T1: Insert/update random keys: KMAP: time: 1.949, size: 15064129, buckets: 33554432, sum: 165525449561381 CMAP: time: 1.649, size: 15064129, buckets: 22145833, sum: 165525449561381 PMAP: time: 2.434, size: 15064129, buckets: 33554431, sum: 165525449561381 FMAP: time: 2.112, size: 15064129, buckets: 33554432, sum: 165525449561381 RMAP: time: 1.708, size: 15064129, buckets: 33554431, sum: 165525449561381 HMAP: time: 2.054, size: 15064129, buckets: 33554432, sum: 165525449561381 TMAP: time: 1.645, size: 15064129, buckets: 33554432, sum: 165525449561381 UMAP: time: 6.313, size: 15064129, buckets: 31160981, sum: 165525449561381 T2: Insert sequential keys, then remove them in same order: KMAP: time: 1.173, size: 0, buckets: 33554432, erased 20000000 CMAP: time: 1.651, size: 0, buckets: 33218751, erased 20000000 PMAP: time: 3.840, size: 0, buckets: 33554431, erased 20000000 FMAP: time: 1.722, size: 0, buckets: 33554432, erased 20000000 RMAP: time: 2.359, size: 0, buckets: 33554431, erased 20000000 HMAP: time: 0.849, size: 0, buckets: 33554432, erased 20000000 TMAP: time: 0.660, size: 0, buckets: 33554432, erased 20000000 UMAP: time: 2.138, size: 0, buckets: 31160981, erased 20000000 T3: Remove random keys: KMAP: time: 1.973, size: 0, buckets: 33554432, erased 23367671 CMAP: time: 2.020, size: 0, buckets: 33218751, erased 23367671 PMAP: time: 2.940, size: 0, buckets: 33554431, erased 23367671 FMAP: time: 1.147, size: 0, buckets: 33554432, erased 23367671 RMAP: time: 1.941, size: 0, buckets: 33554431, erased 23367671 HMAP: time: 1.135, size: 0, buckets: 33554432, erased 23367671 TMAP: time: 1.064, size: 0, buckets: 33554432, erased 23367671 UMAP: time: 5.632, size: 0, buckets: 31160981, erased 23367671 T4: Iterate random keys: KMAP: time: 0.748, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 CMAP: time: 0.627, size: 23367671, buckets: 33218751, repeats: 8, sum: 4465059465719680 PMAP: time: 0.680, size: 23367671, buckets: 33554431, repeats: 8, sum: 4465059465719680 FMAP: time: 0.735, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 RMAP: time: 0.464, size: 23367671, buckets: 33554431, repeats: 8, sum: 4465059465719680 HMAP: time: 0.719, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 TMAP: time: 0.662, size: 23367671, buckets: 33554432, repeats: 8, sum: 4465059465719680 UMAP: time: 6.168, size: 23367671, buckets: 31160981, repeats: 8, sum: 4465059465719680 T5: Lookup random keys: KMAP: time: 0.943, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 CMAP: time: 0.863, size: 23367671, buckets: 33218751, lookups: 34235332, found: 29040438 PMAP: time: 1.635, size: 23367671, buckets: 33554431, lookups: 34235332, found: 29040438 FMAP: time: 0.969, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 RMAP: time: 1.705, size: 23367671, buckets: 33554431, lookups: 34235332, found: 29040438 HMAP: time: 0.712, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 TMAP: time: 0.584, size: 23367671, buckets: 33554432, lookups: 34235332, found: 29040438 UMAP: time: 1.974, size: 23367671, buckets: 31160981, lookups: 34235332, found: 29040438
-
Any suggestions for resources to optimize for memory allocation/reallocation?
using an open-addressing hash table, such as abseil flat_hash_map or tessil/hopscotch-map
PEGTL
-
Use PEGTL to remove my clunky homemade parser
I found a library I wanted to test: Pegtl
-
What are some cool modern libraries you enjoy using?
I like PEGTL
-
We Built a C++ Rendering Engine for the Web
As a professional C++ programmer I feel a lot of the reasons C++ gets this response is because it's simply not "batteries included" like Go or Rust.
C++ is a very powerful, unopinionated language, that gives you a lot of freedom to attack your problem domain the way you best see fit.
If you're writing a networked application, don't use POSIX sockets, go and find a higher level library. If you're parsing complex text formats, don't iterate over buffers with char*'s, go pick up PEGTL[0]. If you're working on graphs, or need to properly index in-memory data, go pick up Boost[1][2]. If you need a GUI, go pick up Qt.
It's extremely common in C++, due to the lack of a universal package management solution, for people to try and "muddle through" and do shit themselves when it's far outside their core competency.
At one of my last employers, the core product was parsing JSON with std::regex, simply because they couldn't be bothered to integrate a JSON library.
[0] https://github.com/taocpp/PEGTL
[1] https://www.boost.org/doc/libs/1_76_0/libs/graph/
[2] https://www.boost.org/doc/libs/1_76_0/libs/multi_index/doc/i...
-
Is there anything like sly for C++?
You are looking for Boost.Spirit (https://www.boost.org/doc/libs/1_76_0/libs/spirit/doc/x3/html/index.html) or PEGTL (https://github.com/taocpp/PEGTL)
-
Why no more Lex/Yakk/ANTLR/whatever?
I personally prefer to use parsing combinator libraries in C++, where the "grammar" is just part of normal C++ and directly integrate. Examples are Boost.Spirit, pegtl, or (my own) lexy.
-
A hand-written recursive descent parser for Lua 5.3, in Lua 5.3!
In case you are still fighting with left-recursion you might be interested in this: https://github.com/taocpp/PEGTL/blob/master/src/example/pegtl/lua53.hpp
-
Ditch regex for parser combinators, a Rust / nom step-by-step guide
I've found https://github.com/taocpp/PEGTL to be easier to use than boost parser generators.
What are some alternatives?
lexy - C++ parsing DSL
cpp-peglib - A single file C++ header-only PEG (Parsing Expression Grammars) library
pybind11 - Seamless operability between C++11 and Python
C++ B-tree - Git mirror of the official (mercurial) repository of cpp-btree
spirit - Boost.org spirit module
sparsepp - A fast, memory efficient hash map for C++
sparsehash-c11 - Experimental C++11 version of sparsehash
sparsehash - C++ associative containers
Optional Argument in C++ - Named Optional Arguments in C++17