optics-dev/Monocle

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Optics library for Scala

Stars: 1.7k
Forks: 207
Open beginner issues: 0
Indexed issues: 51
Avg merge: 7h 59m
Merged PRs (30d): 5

Dominant language: Scala
License: MIT
Last GitHub push: Sep 5, 2026
Latest indexed: Sep 20, 2026
Contributing guide: No contributing guide
Code of conduct: Code of conduct
Beginner labels: No beginner labels indexed

Beginner friendly Everything

Open All

51 open issues indexed

Do a release Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1618 · 4 comments · 1 reaction · Opened Aug 21, 2026
unused local definition warning when defining focus inside a function Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1484 · 2 comments · Opened Dec 12, 2024
Macro expansion raises an error when type of field is written in long hand. Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1482 · Opened Nov 19, 2024
Lenses can't be created for classes with private constructors for Scala 3 Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#1426 · 3 comments · Opened Feb 5, 2024
IncompatibleClassChangeError Open

more info

optics-dev/Monocle#1424 · 1 comment · 1 assignee · Opened Jan 20, 2024
`each` for `Fold` Open

feature macro

optics-dev/Monocle#1417 · 1 assignee · Opened Jan 12, 2024
Add 'Platform' instances Open

feature

optics-dev/Monocle#1416 · 1 assignee · Opened Jan 8, 2024
Is it possible to make @Lenses ignore some fields? Open

feature

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#1411 · 1 comment · Opened Nov 28, 2023
Lens macro-generated for a specific field should allow introspecting the name Open

feature

Difficulty 5/5 Over a week Newbie friendliness 35/100

optics-dev/Monocle#1363 · 2 comments · Opened Jun 9, 2023
Should withDefault be available on lenses with a polymorphic source? Open

feature

optics-dev/Monocle#1340 · 1 assignee · Opened Feb 23, 2023
Mononcle doesn't support `@Lenses` in Scala3. Open

feature

optics-dev/Monocle#1337 · 11 comments · 1 assignee · Opened Jan 31, 2023
Prepare next release Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#1325 · 18 comments · 2 reactions · Opened Nov 17, 2022
Ambient `opaque type` breaks `MkFocus` Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1306 · 4 comments · Opened Oct 11, 2022
[Focus] Compilation fails in Scala 3 in nested case class/object Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

optics-dev/Monocle#1293 · Opened Jul 29, 2022
Compilation error with context bounds Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1259 · 8 comments · Opened Feb 5, 2022
Add refocus for Scala 2 Open

optics-dev/Monocle#1205 · 1 assignee · Opened Sep 10, 2021
MatchError using `as` inside Focus Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 38/100

optics-dev/Monocle#1200 · 4 comments · Opened Sep 1, 2021
Recommended replacement for @Lenses Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#1181 · 4 comments · Opened Jul 21, 2021
[Focus] Improve error standard Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#1122 · Opened Mar 12, 2021
Properly match on the actual `KeywordContext` symbol Open

Difficulty 3/5 1-2 days Newbie friendliness 25/100

optics-dev/Monocle#1080 · 2 comments · Opened Feb 18, 2021
Upgrade to docusorus v2 for Scala 2/3 code samples Open

3.x

Difficulty 3/5 1-2 days Newbie friendliness 38/100

optics-dev/Monocle#1075 · 2 comments · Opened Feb 17, 2021
[Focus] Property based tests for Focus laws Open

3.x

Difficulty 3/5 1-2 days Newbie friendliness 45/100

optics-dev/Monocle#1071 · Opened Feb 17, 2021
Communication strategy Open

3.x

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#1054 · 3 comments · Opened Feb 13, 2021
Variance for optics type parameters Open

3.x

Difficulty 3/5 1-2 days Newbie friendliness 42/100

optics-dev/Monocle#1049 · 1 comment · Opened Feb 11, 2021
Renaming optics type parameters Open

3.x

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1048 · 1 comment · 1 reaction · Opened Feb 11, 2021
Fix StringsSpec Open

bug

optics-dev/Monocle#1040 · 1 assignee · Opened Feb 9, 2021
[Focus] Support polymorphic optics for case classes Open

After 3.0

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#1036 · Opened Feb 8, 2021
[Focus] Non-case class setters in? Open

After 3.0

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#1035 · Opened Feb 8, 2021
[Focus] Non-case class getters Open

After 3.0

Difficulty 3/5 1-2 days Newbie friendliness 45/100

optics-dev/Monocle#1034 · Opened Feb 8, 2021
[Focus] zoom into a common field of an enumeration Open

feature

optics-dev/Monocle#1033 · 4 comments · 5 reactions · 1 assignee · Opened Feb 8, 2021
`Focus` macro Open

3.x

optics-dev/Monocle#1026 · 1 assignee · Opened Feb 8, 2021
`filter` and `filterIndex` names are confusing Open

3.x

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#1023 · 8 comments · Opened Feb 4, 2021
Zip on Lens Open

3.x feature

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#1019 · Opened Feb 3, 2021
Shall we base Foldable on `Iterator`? Open

breaking

optics-dev/Monocle#1013 · 3 comments · 2 reactions · 1 assignee · Opened Jan 21, 2021
Scalafix rules for Monocle 3 Open

3.x

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#1001 · 3 comments · Opened Dec 23, 2020
Broken equality tests on the generated optics Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#947 · Opened Nov 11, 2020
Failing test due to scalacheck change Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#946 · Opened Nov 11, 2020
Cross build to Scala 3 Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#913 · 4 comments · Opened Oct 13, 2020
Lens on a Map do not set a key if it doesn't exist in this Map already Open

FAQ

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#775 · 5 comments · Opened Dec 20, 2019
Use variance in optic type parameters Open

3.x

optics-dev/Monocle#771 · 14 comments · 1 assignee · Opened Dec 19, 2019
Remove polymorphic optics Open

3.x

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#770 · 4 comments · 3 reactions · Opened Dec 19, 2019
Traversal encoding Open

3.x

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#766 · 6 comments · Opened Dec 19, 2019
Add missing instances for ListMap Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#748 · Opened Nov 8, 2019
Monocle scalafix migration Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

optics-dev/Monocle#684 · 3 comments · 3 reactions · Opened Jul 3, 2019
Code snippet from Lens manual does not compile Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

optics-dev/Monocle#522 · 5 comments · 1 reaction · Opened May 12, 2017
Add documentation about Apply optics Open

documentation

Difficulty 3/5 1-2 days Newbie friendliness 45/100

optics-dev/Monocle#452 · Opened Dec 15, 2016
Add partsOf Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

optics-dev/Monocle#384 · Opened Jul 28, 2016
Revisit benchmarks Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

optics-dev/Monocle#376 · Opened Jul 6, 2016
Create an Internals.md document documenting the internals of Monocle Open

documentation

Difficulty 5/5 Over a week Newbie friendliness 35/100

optics-dev/Monocle#270 · 2 comments · Opened Oct 15, 2015
Include section/retraction pairs in the optics hierarcy Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

optics-dev/Monocle#186 · 12 comments · Opened Feb 17, 2015

optics-dev/Monocle

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