Go Reference Go 1.18 Fuzz

Juniper is a library of extensions to the Go standard library using generics, including containers, iterators, and streams.

  • container/tree contains a Map and Set that keep elements in sorted order. They are implemented using a B-tree, which performs better than a binary search tree.
  • container/deque contains a double-ended queue implemented with a ring buffer.
  • container/xheap contains a min-heap similar to the standard library’s container/heap but more ergonomic, along with a PriorityQueue that allows setting priorities by key.
  • container/xlist contains a linked-list similar to the standard library’s container/list, but type-safe.
  • xslices contains some commonly-used slice operations, like Insert, Remove, Chunk, Filter, and Compact.
  • iterator contains an iterator interface used by the containers, along with functions to manipulate them, like Map, While, and Reduce.
  • stream contains a stream interface, which is an iterator that can fail. Useful for iterating over collections that require I/O. It has most of the same combinators as iterator, plus some extras like Pipe and Batch.
  • parallel contains some shorthand for common uses of goroutines to process slices, iterators, and streams in parallel, like parallel.MapStream.
  • xsort contains extensions to the standard library package sort. Notably, it also has the definition for xsort.Less, which is how custom orderings can be defined for sorting and also for ordered collections like from container/tree.
  • You can probably guess what’s in the packages sets, xerrors, xmath, xmath/xrand, xsync, and xtime.

Packages that overlap directly with a standard library package are named the same but with an x prefix for “extensions”, e.g. sort and xsort. xslices is named so because a slices package is planned for Go 1.19.

See the docs for more.


Things should basically work. The container packages have been tested decently well using the new built-in coverage-based fuzzer (it’s a pleasure, by the way, other than having to translate from the built-in fuzz argument types). container/tree has been benchmarked and tweaked for some extra performance. It’s far from hyper-optimized, but should be efficient enough. Most of the simpler functions are tested only with their examples.

Since I no longer work at a megacorp running a huge global deployment of Go, I no longer have that at my disposal to certify any of this as battle-hardened. However, the quality of code here is high enough that I would’ve been comfortable using anything here in the systems that I worked on.


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