strict-containers: Strict containers.

[ bsd3, data, data-structures, library ] [ Propose Tags ]

This package provides strict versions of some standard Haskell containers - including HashMap, IntMap, Map, Sequence, and Vector.

The reasoning is the same as that for our strict package - though some containers already define strict operations that force their inputs, the underlying data type is shared between the lazy and strict variants, i.e. by default lazy. In particular, instances are defined lazily on the common type, meaning that external utilities such as lens, optics, and deserialisation instances e.g. for binary and serialise, all work lazily and there is not even the option to go strict.

This package defines separate data types, to avoid these problems. Instances can then be defined on these fully-strict data types.

To be clear, the "strict" vs "lazy" discussion refers to the values of a map or the elements of a sequence. The standard variants of these data structures that can be lazy-or-strict are already always-strict in their keys (for maps) and lengths (for sequences) respectively. This is also why we don't define strict variants of sets here, since the standard variants are already strict in their elements.

Note: generally, instances for strict containers violate their respective laws in the presence of bottom (undefined, error, infinite-loop). In the absence of bottom, laws are preserved.

This library mirrors the API of the standard lazy-or-strict variants in containers and unordered-containers, including methods and fundamental instances. It also contains instances for binary and indexed-traversable. More instances are defined in other packages, e.g. strict-containers-lens and strict-containers-serialise.

The current version of this library has been autogenerated from:

  • containers v0.6.6

  • unordered-containers v0.2.19.1

  • vector vector-


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Versions [RSS] 0.1, 0.2
Change log
Dependencies array (>=, base (>= && <5), binary (>= && <0.9), containers (>=0.6.6 && <0.7), deepseq (>=1.2 && <1.5), hashable (>= && <1.5), indexed-traversable (>=0.1.1 && <0.2), primitive (>= && <0.8), strict (>=0.4 && <0.6), template-haskell, unordered-containers (>= && <0.3), vector (>= && <0.14), vector-binary-instances (>= && <0.3) [details]
License BSD-3-Clause
Copyright (c) 2021 by Ximin Luo
Maintainer Ximin Luo <>
Revised Revision 1 made by ErikDeCastroLopo at 2023-09-21T02:56:36Z
Category Data, Data Structures
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Uploaded by infinity0 at 2022-12-12T12:50:03Z
Reverse Dependencies 2 direct, 0 indirect [details]
Downloads 672 total (30 in the last 30 days)
Rating 2.0 (votes: 1) [estimated by Bayesian average]
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Status Docs available [build log]
Last success reported on 2022-12-12 [all 1 reports]