Go modules · #143 by repository stars

github.com/samber/lo

v1.53.0samber/lo ↗New releases in your daily digest, changelog included.

Last release 7 days ago
01 Oct 2026
Ships on a steady schedule
a new release about every 2 weeks
Rarely documented
notes for 10 of the last 60 stable releases
Nothing withdrawn
no release was ever pulled
5 years old
321 releases · first in 2022

Release timeline

321 releases since 2022

20222023202420252026

20222026

One column per quarter.

Releases

v1.53.02 Mar 2026Deprecated
refactor: remove helpers deprecated for more than 3y by @samber in #810
Announcing the latest release of lo with lots of good gifts! 🎁

🌊 First, a big thanks to @d-enk for making lots of performance improvements in the recent weeks.

🧪 Second, this release introduces a new simd experimental package. If you run on an amd64 architecture and a recent CPU, you can perform very fast operations thanks to SIMD CPU instructions.
-> Documentation: https://lo.samber.dev/docs/experimental/simd

💥 Third, this version adds *Err variants of many lo helpers (like MapErr, FlatMapErr, ReduceErr, etc.) whose callbacks can return an error and short-circuit execution when one occurs.

Note
The simd sub-package is considered not stable. We might break the initial API based on developers' feedback in the coming months.

Features & improvements

feat: adding SIMD helpers by @samber in #801

feat: adding Error variants: MapErr, FlatMapErr, ReduceErr... by @samber in #823

feat: support for buffer iterator by @mimol91 in #824

feat: add Take, TakeWhile, FilterTake, Window, and Sliding functions by @juliazadorozhnaya in #760

feat: add a Concat slice function. by @FGasper in #714

feat: add iterator slice helpers by @juliazadorozhnaya in #791

feat(it): adding loit.Concat by @samber in #722

feat: Allow Union/Intersect to take many lists by @frankywahl in #181

feat: Add Clone function to return shallow copy of slice collections by @quexer in #732

feat: IntersectBy by @ghosx in #653

feat: Support Custom Assert by @RelicOfTesla in #755

feat: Must support Custom error handler. by @RelicOfTesla in #752

feat: WithoutNth handle non-comparable types by @urisimchoni in #774

refactor: remove unnecessary type arguments in NewThrottle by @d-enk in #773

refactor: lo.IntersectBy + adding loit.IntersectBy + adding doc by @samber in #739

fix: rename IsSortedByKey to IsSortedBy by @NathanBaulch in #735

fix(iter/tuples): support break iteration over Zip[By] seq by @d-enk in #757

fix(it.Mode): align behavior with lo.Mode and ensure consistent slice… by @intojhanurag in #711

fix: improve Clone function to preserve nilness and avoid liveness issues by @quexer in #740

fix: reset n counter per iteration in it.Replace by @LikimiaD in #799

fix: make Ellipsis operate on runes instead of bytes to prevent Unicode truncation by @veeceey in #796

fix: correct DropByIndex handling of negative indices out of bounds by @d-enk in #778

Deprecation

refactor: remove helpers deprecated for more than 3y by @samber in #810

Performance improvements

feat: Optimize UniqMap to reduce unnecessary slice preallocation by @ivolkoff in #710

refactor(it): simplify DropLast, TrimSuffix, TrimPrefix and use range loops by @d-enk in #782

bench: fix iterators to actually iterate in benchmarks by @d-enk in #781

refactor: simplify slice cut/trim prefix/suffix functions by @d-enk in #787

perf: optimize Sliding by pre-allocating result capacity by @d-enk in #783

refactor: improve SamplesBy performance and revert non-panic behavior for negative count by @d-enk in #786

feat(perf): speed up some functions with linear complexity O=n2 -> O=2n by @samber in #726

perf: only allocate a single map in Intersect by @NathanBaulch in #736

perf: preallocate Words string buffer by @NathanBaulch in #728

refactor: improve lo[it].Intersect[By] readability and performance by @d-enk in #756

perf: preallocate result slice in SamplesBy by @d-enk in #766

perf: optimize PartitionBy by eliminating redundant append by @d-enk in #765

perf: correct prealloc of the result in FindUniques/Duplicates[By] by @d-enk in #764

perf: use Ternary() instead If().Else() in Range/RangeFrom by @d-enk in #770

perf: optimize it.Trim to use DropLastWhile(DropWhile(...)) by @d-enk in #780

perf: replace Min/Max(Range) with Min/MaxIndexBy in DispatchingStrategy by @d-enk in #779

perf: preallocate result slice in RangeWithSteps by @d-enk in #820

perf: avoid unnecessary error allocation in NthOr, NthOrEmpty by @d-enk in #817

perf: optimize Zip and ZipBy functions by @d-enk in #818

perf: lazy it.Reverse iteration instead of in-place mutation by @d-enk in #814

perf: optimize Substring to work directly with strings instead of converting to runes by @d-enk in #822

perf: optimize it.CountBy by removing Filter iterator chain by @d-enk in #813

perf: optimize it.Find to avoid unnecessary allocations by @d-enk in #811

perf: optimize it.ContainsBy/EveryBy/SomeBy/NoneBy to avoid unnecessary allocations by @d-enk in #812

refactor: simplify for loop by @d-enk in #772

refactor: remove some redundant checks by @d-enk in #771

refactor: simplify it.HasSuffix implementation by @d-enk in #767

refactor: improve Slice logic and fix docstring by @d-enk in #785

Thanks @d-enk !!

Other (doc, tests, style...)

test: adding missing test cases to ellipsis by @samber in #809

fix(test): Increase timeout values in concurrency tests by @samber in #775

refactor: reorganize llms.txt and add missing helpers by @samber in #723

Fix Clone() go playground link in README by @sethisernhagen in #761

Intersect CI test fix by @frankywahl in #731

lint: fix inconsistent callback function parameter names by @NathanBaulch in #730

style: fix linter by @samber in #802

fix: update Play links for Async functions in concurrency.go by @Weeranieb in #724

lint: use Keyify internally by @NathanBaulch in #691

Fix references to "lo" instead of "ro" by @pgr0ss in #713

style: reduce the number of files in root directory by @samber in #719

style: move img/ directory into docs/static/img by @samber in #721

refactor: use separate variables for each iter.Pull in it.Zip functions by @d-enk in #816

refactor: remove redundant map zero value initialization in throttleBy by @d-enk in #815

doc: explain chunkstring inconsistency by @samber in #789

doc: fix package name from "lo" to "it" by @samber in #794

doc(exp,simd): adding warning about API stability for code under exp/ by @samber in #808

doc(maxby): adding comment to explain inconsistency by @samber in #727

doc: adding some conventions for callback naming by @samber in #738

docs: fix typos by @alexandear in #745

chore(tests): some test improvements by @samber in #725

chore(ci): improve go version management in CI by @samber in #806

chore(ci): adding codeql by @samber in #819

style(simd): rename sse to avx by @samber in #821

Dependencies

chore(deps): bump lodash from 4.17.21 to 4.17.23 in /docs by @dependabot[bot] in #777

chore(deps): bump webpack from 5.102.0 to 5.105.0 in /docs by @dependabot[bot] in #793

chore(deps): bump actions/setup-node from 5 to 6 by @dependabot[bot] in #716

chore(deps): bump marked from 16.3.0 to 16.4.1 in /docs by @dependabot[bot] in #717

chore(deps): bump js-yaml from 3.14.1 to 3.14.2 in /docs by @dependabot[bot] in #741

chore(deps): bump node-forge from 1.3.1 to 1.3.2 in /docs by @dependabot[bot] in #744

chore(deps): bump ajv from 6.12.6 to 6.14.0 in /docs by @dependabot[bot] in #807

chore(deps): bump actions/checkout from 5 to 6 by @dependabot[bot] in #747

chore(deps): bump golangci/golangci-lint-action from 8 to 9 by @dependabot[bot] in #746

chore(deps): bump marked from 16.4.1 to 17.0.1 in /docs by @dependabot[bot] in #748

chore(deps): bump mdast-util-to-hast from 13.2.0 to 13.2.1 in /docs by @dependabot[bot] in #750

chore(deps): bump express from 4.21.2 to 4.22.1 in /docs by @dependabot[bot] in #751

New Contributors

@ivolkoff made their first contribution in #710

@intojhanurag made their first contribution in #711

@pgr0ss made their first contribution in #713

@Weeranieb made their first contribution in #724

@frankywahl made their first contribution in #181

@quexer made their first contribution in #732

@alexandear made their first contribution in #745

@juliazadorozhnaya made their first contribution in #760

@sethisernhagen made their first contribution in #761

@RelicOfTesla made their first contribution in #755

@urisimchoni made their first contribution in #774

@LikimiaD made their first contribution in #799

@veeceey made their first contribution in #796

Full Changelog: v1.52.0...v1.53.0

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v1.53.0 Latest

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v1.52.08 Oct 2025Deprecated

feat(generator): deprecate lo.Generator in favor of go "iter" package by @samber in #700

Thrilled to announce the latest release of samber/lo!

This version brings major improvements:

A new it/ sub-package for everything related to the iter package added in Go 1.23. Big up to @NathanBaulch for its help on this
A new documentation -> lo.samber.dev
Lots of micro fixes and performance improvements
Better code quality with many more linters

✨ A good introduction to streams in Go !

What's Changed

fix(chunk): Copy chunk in a new slice by @samber in #648
fix(zipx): fix the max length calculation by @samber in #649
fix(retry): fix potential race condition in debounce callback by @samber in #650
feature: add Mode function with tests and documentation by @ghosx in #644
add FilterKeys for map by @rasha108bik in #631
feat: adding FilterValues and fix FilterKeys signature by @samber in #661
#662
fix: more consistent panic strings by @NathanBaulch in #678
fix: minor example issues by @NathanBaulch in #676
feat: preserve type alias in DropByIndex and WithoutBy by @NathanBaulch in #675
feat: adding hassuffix + hasprefix by @samber in #680
Added Cut, CutPrefix, CutSuffix by @xelavopelk in #666
Add TrimXXX helpers by @samber in #683
fix(string): fix division by zero by @samber in #684
fix: avoid recover() if possible by @NathanBaulch in #685
fix: panic when passing -1 to Drop by @NathanBaulch in #688
perf: avoid Keyify twice in Trim by @NathanBaulch in #689
feat: new iter package by @NathanBaulch in #672
feat: from slice to map with index passed by @mabrarov in #697
feat: from slice/iterator to map with index passed by @mabrarov in #698
feat(generator): deprecate lo.Generator in favor of go "iter" package by @samber in #700
perf: optimization of map access by @mabrarov in #692
perf: optimize map access everywhere by @NathanBaulch in #693

Tests

fix(tests): fix flaky time-based tests by @samber in #699

Style

lint: unit test improvements by @NathanBaulch in #674
lint: fix CI warnings and avoid named return parameters by @NathanBaulch in #682
lint: enable 7 more linters by @NathanBaulch in #686
lint: enable gofumpt extra rules by @NathanBaulch in #690
Style/rename internal rand by @samber in #701
lint: Apply testifylint linter recommendations by @NathanBaulch in #669
Style add golangci config by @samber in #670
chore: minor whitespace fixes by @NathanBaulch in #677

Documentation

New documentation for "lo" 🎨 by @samber in #703
doc: add it/mutable/parallel sub-package to llms.txt by @samber in #707
docs: lots of various doc improvements by @samber in #706
docs: adding go playground examples to it/ package by @samber in #708
docs: Fix the Markdown syntax that is not displaying correctly by @mengxunQAQ in #658
doc: add examples for find.go by @samber in #681
docs: Fix Product and ProductBy documentation by @markhildreth-gravity in #647
chore(deps-dev): bump typescript from 5.6.3 to 5.9.3 in /docs by @dependabot[bot] in #704
docs: grammar improvements by @NathanBaulch in #673

Other

chore(deps): bump actions/setup-go from 5 to 6 by @dependabot[bot] in #695
chore(deps): bump github.com/stretchr/testify from 1.11.0 to 1.11.1 by @dependabot[bot] in #663
chore(deps): bump actions/checkout from 4 to 5 by @dependabot[bot] in #659
chore(deps): bump github.com/stretchr/testify from 1.10.0 to 1.11.0 by @dependabot[bot] in

New Contributors

@markhildreth-gravity made their first contribution in #647
@rasha108bik made their first contribution in #631
@xelavopelk made their first contribution in #666
@mabrarov made their first contribution in #692

Full Changelog: v1.51.0...v1.52.0

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v1.51.011 Jun 2025

Fixed the error in the usage example of lo.Latest in readme.md by @ghosx in #627

What's Changed

Fixed the error in the usage example of lo.Latest in readme.md by @ghosx in #627
feat(assertions): add Assert and Assertf by @your-diary in #638

Doc

docs: Add a more precise description to the Ellipsis function by @mengxunQAQ in #635
docs: Fix description for LastOrEmpty and LastOr by @vaihtovirta in #636
docs: fix wrong variable name for mutable map example by @sunjayaali in #637

Dependencies

fix(ci): correct cleanup deps - remove all *_test.go files using find by @d-enk in #630
Revert "chore(deps): bump golang.org/x/text from 0.22.0 to 0.24.0" by @samber in #626
chore(deps): bump golang.org/x/text from 0.22.0 to 0.24.0 by @dependabot in #625
chore(deps): bump golangci/golangci-lint-action from 7 to 8 by @dependabot in #628

New Contributors

@ghosx made their first contribution in #627
@mengxunQAQ made their first contribution in #635
@vaihtovirta made their first contribution in #636
@your-diary made their first contribution in #638

Full Changelog: v1.50.0...v1.51.0

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v1.50.026 Apr 2025

Here is the 50th minor version !! 🔥🥂

What's Changed

Here is the 50th minor version !! 🔥🥂

New methods

Implemented GroupByMap by @maryum375 in #443
feat: Add NthOr and NthOrEmpty functions by @edvardsanta in #611
feat: adding FilterMapToSlice by @samber in #623
feat(mutable): adding Map, MapI, Filter, FilterI by @samber in #577
Add ElementsMatch, ElementsMatchBy by @senago in #589

Improvements

Perf(slice): Optimize iteration function parameters and add test cases by @shuqingzai in #587
Preallocate result in FilterMap by @renbou in #622

Documentation

docs: modify mutable.shuffle example code and Go Playground links by @ebina4yaka in #595
fix: Issue 605 (README for Ternary() by @peterhoward42 in #606
docs: add play link for ChunkEntries example in README by @oswaldom-code in #600
doc: update CoalesceXXX demo and result by @jialeicui in #594
docs: fix typo in readme by @ahmedabdou14 in #620

Dependencies

chore(deps): bump golang.org/x/text from 0.21.0 to 0.22.0 by @dependabot in #590
chore(deps): bump golang.org/x/text from 0.22.0 to 0.24.0 by @dependabot in #618
chore(deps): bump golangci/golangci-lint-action from 6 to 7 by @dependabot in #616

New Contributors

@maryum375 made their first contribution in #443
@shuqingzai made their first contribution in #587
@ebina4yaka made their first contribution in #595
@jialeicui made their first contribution in #594
@peterhoward42 made their first contribution in #606
@edvardsanta made their first contribution in #611
@ahmedabdou14 made their first contribution in #620
@renbou made their first contribution in #622

Full Changelog: v1.49.1...v1.50.0

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v1.49.128 Jan 2025

fix(product + productby): fix empty slice behavior by @samber in #584

What's Changed

fix(product + productby): fix empty slice behavior by @samber in #584

Full Changelog: v1.49.0...v1.49.1

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v1.49.027 Jan 2025

feat: add SampleBy and SamplesBy by @bramvandewalle in #516

What's Changed

feat: add SampleBy and SamplesBy by @bramvandewalle in #516
feat: Add IsNotNil by @haoxins in #523
feat: Implement ChunkMap Function (#533) by @oswaldom-code in #538
feat: Add NewThrottle by @Lee-Minjea in #427
feat: adding FilterSliceToMap by @samber in #581
feat: add Product and ProductBy functions by @JohnDevitt in #566

New Contributors

@bramvandewalle made their first contribution in #516
@oswaldom-code made their first contribution in #538
@Lee-Minjea made their first contribution in #427

Full Changelog: v1.48.0...v1.49.0

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v1.48.025 Jan 2025Deprecated

feat: deprecate lo.Reverse and move it to lom.Reverse by @samber in #576

What's Changed

Feature

feat: add (Min|Max)Index(By) by @aria3ppp in #569
feat: add UniqMap by @nicklaus-dev in #527
feat: add CrossJoin function by @JohnDevitt in #567
feat: Implement CoalesceOrEmptySlice Function by @chg1f in #542
feat: adding WithoutNth by @samber in #575
feat: deprecate lo.Reverse and move it to lom.Reverse by @samber in #576
feat: deprecate lo.Shuffle and move it to lom.Shuffle by @samber in 699707a#comments
feat: adding lo.BufferWithContext by @samber in #580
feat: add SliceToSet by @nicklaus-dev in #514
feat: add WithoutBy by @nicklaus-dev in #515
feat: add lom.Fill by @samber

Fix

fix: change examples for MapKeys and MapValues by @luxcgo in #341
fix: order of GroupBy and PartitionBy by @liyishuai in #572

Refactor

refactor RandomString function by @pigwantacat in #524

New Contributors

@luxcgo made their first contribution in #341
@haoxins made their first contribution in #522
@muya made their first contribution in #521
@NathanBaulch made their first contribution in #519
@jiz4oh made their first contribution in #535
@guyareco2 made their first contribution in #537
@pigwantacat made their first contribution in #524
@snamiki1212 made their first contribution in #541
@dependabot made their first contribution in #554
@JasonnnW3000 made their first contribution in #571
@liyishuai made their first contribution in #572
@aria3ppp made their first contribution in #569
@sunjayaali made their first contribution in #544
@SnowOnion made their first contribution in #543
@nicklaus-dev made their first contribution in #527
@JohnDevitt made their first contribution in #567
@chg1f made their first contribution in #542

Full Changelog: v1.47.0...v1.48.0

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v1.47.013 Aug 2024

feat: Improve Substring by @liujundezhanghao in #496

What's Changed

feat: Improve Substring by @liujundezhanghao in #496
doc: Wrong method reference and output in readme by @ColeZia in #497
doc: Fix documentation for Duration3 by @gecko655 in #502
feat: add FromSlicePtr by @mash in #217
feat: adding FromSlicePtrOr by @samber in #506
feat: Keys+Values: accept multiple maps (vaargs) - Adding UniqKeys+UniqValues by @shivamrazorpay in #503
doc: Update foreachwhile readme.md by @Sianao in #508

New Contributors

@liujundezhanghao made their first contribution in #496
@ColeZia made their first contribution in #497
@gecko655 made their first contribution in #502
@mash made their first contribution in #217
@shivamrazorpay made their first contribution in #503

Full Changelog: v1.46.0...v1.47.0

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v1.46.015 Jul 2024

fix: chunk memory leak, bug fix by @mihir20 in #491

What's Changed

fix: chunk memory leak, bug fix by @mihir20 in #491
feat: add WaitForWithContext by @ccoVeille in #480
add ForEachCondition implement by @Sianao in #485

New Contributors

@mihir20 made their first contribution in #491
@ccoVeille made their first contribution in #480
@Sianao made their first contribution in #485

Full Changelog: v1.45.0...v1.46.0

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v1.45.013 Jul 2024

perf: preallocate in Assign by @pmalek in #484

What's Changed

perf: preallocate in Assign by @pmalek in #484
feat: adding EarliestBy and LatestBy functions by @timych in #489

New Contributors

@pmalek made their first contribution in #484
@timych made their first contribution in #489

Full Changelog: v1.44.0...v1.45.0

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v1.44.030 Jun 2024