*Top Picks:* - Is Servant http://haskell-servant.github.io/the most type-safe HTTP server library ever? Are the type signatures hard to read https://news.ycombinator.com/item?id=9519782#up_9520750? In addition to its utmost relevance as a web library, Servant is also an awesome case study in the type safety vs type readability trade-off spectrum, brought to you by Alp Mestanogullari and Julian Arni. HN https://news.ycombinator.com/item?id=9519782 and /r/haskell http://www.reddit.com/r/haskell/comments/35hiie/servant_04_released/ - Ozan Sener compiles Pandoc into JS via GHCJS and creates a web interface to it using the Reflex FRP library https://github.com/ryantrinkle/reflex. Markup.Rocks https://github.com/osener/markup.rocks is much loved on /r/haskell http://www.reddit.com/r/haskell/comments/35ax22/ive_compiled_pandoc_with_ghc.... See also HN https://news.ycombinator.com/item?id=9512293. - Is Haskell a "Startup Secret Weapon"? Alexandr Kurilin reveals adoption challenges https://github.com/commercialhaskell/commercialhaskell/blob/master/usage/fro... at Front Row Education https://www.crunchbase.com/organization/front-row. Among them, slow build times. Also, "senior developers [that] get very frustrated when something wouldn't compile for hours and they couldn't find any help to move forward." Comments on HN https://news.ycombinator.com/item?id=9519924 and /r/haskell http://www.reddit.com/r/haskell/comments/35h8vh/how_front_row_education_uses... . - At Facebook, Bryan O'Sullivan debugs aeson's gigabyte space leak http://www.serpentine.com/blog/2015/05/13/sometimes-the-old-ways-are-the-bes... on decoding a JSON megabyte of non-stop backslashes. Culprit? The streaming interface didn't match the use case. In place of streaming, Bryan now blasts bytes into a single big buffer, gaining 27x speed and 42x memory reduction. Comments on HN https://news.ycombinator.com/item?id=9540389, Proggit http://www.reddit.com/r/programming/comments/35udjh/fixing_a_haskell_perform..., /r/haskell http://www.reddit.com/r/haskell/comments/35udfy/fixing_an_aeson_performance_... . - Paul Chiusano's Unison programming platform http://unisonweb.org/2015-05-07/about.html hits the HN https://news.ycombinator.com/item?id=9512955 and /r/haskell http://www.reddit.com/r/haskell/comments/35cop9/unison_a_nextgeneration_prog... headlines. Features include a browser-based UI that constrains edits to those that are well-typed. Also, DRY-ness up the wazoo: every type and term is uniquely identified by a hash a la Git. - Joey Hess reports http://www.reddit.com/r/haskell/comments/35bw0b/at_last_debian_unstable_has_... that Debian unstable now has a working GHCi for ARM. The Template Haskell challenges have been surmounted. - Garrison Jensen blows the whistle http://www.garrisonjensen.com/2015/05/13/haskell-programs-are-lies.html on the impostor sieve on the front page of Haskell.org. In jest. A festive one-upmanship of fondly treasured code ensues on /r/haskell http://www.reddit.com/r/haskell/comments/35vc31/the_real_way_to_generate_a_l.... And since bad publicity is better than no publicity, we owe kudos to Garrison. HN-worthy https://news.ycombinator.com/item?id=9541478. - Michael Snoyman decries use of ExceptT IO https://www.fpcomplete.com/user/commercial/content/exceptions-best-practices for exception handling because the user exception data type creates misleading expectations of comprehensiveness. The gotcha is that it doesn't cover IO exceptions! Furthermore, distinct exception types mean that the corresponding code can't compose. Instead? Use MonadThrow. /r/haskell http://www.reddit.com/r/haskell/comments/35sk6w/best_practices_for_using_exc... - JP Moresmau steps down as chief of EclipseFP http://jpmoresmau.blogspot.com/2015/05/eclipsefp-end-of-life-from-me-at-leas... and the companion Haskell packages BuildWrapper, ghc-pkg-lib, and scion-browser. Without anyone to take his place, the sun sets on EclipseFP. But the sun continues to shine on ide-backend (previously reported http://haskell.1045720.n5.nabble.com/Haskell-Weekly-News-td5768107.html), a GHC API wrapper akin to BuildWrapper. JP spitballs http://haskell.1045720.n5.nabble.com/IDE-backend-Atom-editor-td5809240.html on how he might move on to the Atom editor, jiggering it to use ide-backend-client. /r/haskell http://www.reddit.com/r/haskell/comments/35y5v1/jp_moresmaus_blog_eclipsefp_... - Tatsuya Hirose translates Go By Example into Haskell. GBE https://gobyexample.com/ comprises code samples annotated for an experienced programmer new to Go. For this first cut http://lotz84.github.io/haskellbyexample/, Tatsuya stays close to the original and creates Go-ish, imperative Haskell. Already good for Go-to-Haskell crossovers. Potentially excellent when done in idiomatic Haskell. /r/haskell http://www.reddit.com/r/haskell/comments/3586e3/haskell_by_example/ - Tomas Petricek observes http://tomasp.net/blog/2015/against-types/ the diversity of type theories and type systems and posits harm in any attempt at a single all-encompassing capture of the meaning of 'types'. What about unsound types? He doesn't offer a way out for those stuck with the appellation. Comments on HN https://news.ycombinator.com/item?id=9545540 and /r/haskell http://www.reddit.com/r/haskell/comments/35zzvu/against_the_definition_of_ty... . - John De Goes launches a crowdfund https://www.indiegogo.com/projects/record-all-lambdaconf-2015-talks to solicit $15,000 for video-recording 70 talks at LambdaConf 2015, which features many known Haskell programmers. /r/haskell http://www.reddit.com/r/haskell/comments/35n14p/indiegogo_record_all_lambdac... - A redditor asks ex-Lispers what it's like moving to Haskell http://www.reddit.com/r/haskell/comments/35bybo/lispers_of_haskell_whats_you.... "I miss Lisp parens" is a frequent answer. Also, Lisp has a better REPL experience. A biggie upside? The refactoring afforded by Haskell's type system. *Tip of the Week:* - When programming fractals, use the LLVM backend https://ghc.haskell.org/trac/ghc/ticket/10400#comment:3 because it's "usually good at optimizing this kind of non-allocating code" as Reid Barton advises. -- Kim-Ee