What Color is Your Function?
What Color is Your Function? by Bob Nystromby Bob Nystrom
Shares rank 37 of 60 articles by recommenders
Recommended as a clear, widely praised explanation of function colors and async; critics say it covers only part of concurrency and offers little deep insight.
Recommended as a clear, widely praised explanation of function colors and async; critics say it covers only part of concurrency and offers little deep insight.
5 people gave an opinion
- recommend it
- 5
- criticize it
- 0
- approval share
- 100%
Recommended in 3 of 13 months
- November 2025: recommended
- December 2025: not recommended
- January 2026: recommended
- February 2026: not recommended
- March 2026: not recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 5 people recommend itNeeds 10 or more, not met.
- Nobody criticizes itNeeds 2 to 1 or better, met.
- Recommended in 3 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Makes the function color problem easy to grasp
“it makes a certain ick very easy to feel and understand, but it doesn't offer much in terms of profound knowledge”
Comment from 26 May 2026 in “What Color is Your Function? (2015)” Praised as a wonderful article
“the (wonderful!) function color article”
Comment from 23 Jan 2026 in “Kotlin's Rich Errors: Native, Typed Errors Without Exceptions”
What people warn about
Each mark is one comment
Covers only part of concurrency
“they tend to pick on a a subset of the properties that make up this complex topic of concurrency”
Comment from 2 Nov 2025 in “A Few Words About Async” Shallow on profound knowledge
“it makes a certain ick very easy to feel and understand, but it doesn't offer much in terms of profound knowledge”
Comment from 26 May 2026 in “What Color is Your Function? (2015)” Heavy chained closures at runtime
“his main criticism here is the big mess of chained closures this makes at runtime, compared with pausing/resuming green threads”
Comment from 26 May 2026 in “What Color is Your Function? (2015)”
Other articles people recommend
The four most recommended other articles, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Programming as Theory Buildingby Peter Naur | 32 | 0 | 100% | 7 | — | Approved |
| Ur-Fascismby Umberto Eco | 18 | 2 | 90% | 8 | — | Approved |
| Politics and the English Languageby George Orwell | 14 | 0 | 100% | 5 | — | Approved |
| The Grug Brained Developer by Carson Gross | 13 | 1 | 93% | 9 | — | Approved |
| What Color is Your Function?by Bob NystromThis page | 5 | 0 | 100% | 3 | — | — |
What people said
4 of the 5 comments that mention it, newest first. Each links to the original comment.
“his main criticism here is the big mess of chained closures this makes at runtime, compared with pausing/resuming green threads”
“it makes a certain ick very easy to feel and understand, but it doesn't offer much in terms of profound knowledge”
“the (wonderful!) function color article”
“they tend to pick on a a subset of the properties that make up this complex topic of concurrency”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.