Re: [Haskell-cafe] Problem with HXT `when`
Hi Albert,
thanks for your answer. It helped in some other issues I have.
I did experiment with parenthesis, but obviously not in the right place.
I found the filterA arrow to do the thing I want, like this:
getRowWithHeading caption =
filterA (deep (hasName th / hasText (==caption) )) /
hasName td
getChildren
I like to ask you if you might know the answer to the following:
In a structure
+---XTag a
| +---XText A text 1
|
+---XText Plain text 1
|
+---XTag a
| +---XText A text 2
|
+---XText Plain text 2
...
I must combine A text 1 with Plain text 1, etc., but they are in sequence on
the same level.
Is it possible, in a simple way, to do it in a single arrow flow?
(Or only outside the arrow by pairing the list items?)
Something like:
hasName a / getText (getNextItem??? getText)
I assume not, but I'm still new to Haskell and would like to check.
br,
vlatko
Original Message
Subject: Re: [Haskell-cafe] Problem with HXT `when`
From: Albert Y. C. Lai tre...@vex.net
To: haskell-cafe@haskell.org
Date: 25.09.2013 03:22
On 13-09-21 05:13 AM, Vlatko Basic wrote:
I'd like to extract A texts from row with header Caption, and have
come up with this
runX $ doc
(deep (hasName tr) --
filter only TRs
withTraceLevel 5 traceTree --
shows correct TR
`when`
deep (
hasName th
-- filter THs with specified text
getChildren hasText (==Caption)
) -- inner deep
getChildren hasName td -- shouldn't here be only
one TR?
getChildren
)
getName (getChildren getText) -- list has TDs
from all three TRs
Operator precedences:
infixr 1
`when` infixl 9 (default)
Therefore, this expression redundantly parenthesized and systematically indented
to ensure that you are on the same page with the computer is:
runX $
doc
( deep (hasName tr)
-- begin{conditionally prints but otherwise is arr id}
( withTraceLevel 5 traceTree
`when`
deep ( hasName th
getChildren
hasText (==Caption)
) -- inner deep
)
-- end{conditionally prints but otherwise is arr id}
getChildren
hasName td
getChildren
)
( getName (getChildren getText) )
The condition on thCaption/th ends up controlling trace messages only; it is
not used to limit real processing.
when doesn't help even when used correctly: it doesn't ban data. guards and
containing ban data, but you have to put them at the right place, i.e.,
parenthesize correctly.
runX $
doc
( deep ( hasName tr
`containing`
deep ( hasName th
getChildren
hasText (==Caption)
)
)
getChildren
hasName td
getChildren
)
( getName
(getChildren getText)
)
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Re: [Haskell-cafe] Hackage 2 switchover imminent
On 24 September 2013 22:38, Duncan Coutts dun...@well-typed.com wrote: For issues with accounts or permissions please contact the administrators by email at adm...@hackage.haskell.org Sorry, that should be: ad...@hackage.haskell.org Ie singular admin, not plural. I got myself confused because there are several admins. -- Duncan Coutts, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Weekly News: Issue 281
Welcome to issue 281 of the HWN, an issue covering crowd-sourced bits of information about Haskell from around the web. This issue covers the week of September 15 to 21, 2013. Quotes of the Week * jmcarthur: weak algebraic structures? ha! i prefer my algebraic structures to put up more of a fight. * newsham: teach a man to pred and he will pred to zero. teach a man to succ and he will succ forever Top Reddit Stories * Edward C++Hands Domain: bartoszmilewski.com, Score: 83, Comments: 102 On Reddit: [1] http://goo.gl/64LLo4 Original: [2] http://goo.gl/0H0yr7 * Perfect streaming using `pipes-bytestring` Domain: haskellforall.com, Score: 59, Comments: 45 On Reddit: [3] http://goo.gl/oSlzZP Original: [4] http://goo.gl/8xwZjc * Adding safe coercions to Haskell Domain: joachim-breitner.de, Score: 58, Comments: 23 On Reddit: [5] http://goo.gl/2vs5M9 Original: [6] http://goo.gl/n0RYA3 * Which programming languages do you like besides Haskell, and why? Domain: self.haskell, Score: 55, Comments: 104 On Reddit: [7] http://goo.gl/nzgwJQ Original: [8] http://goo.gl/nzgwJQ * GHC HEAD: merged checkable minimal complete definitions (#7633) Domain: ghc.haskell.org, Score: 48, Comments: 36 On Reddit: [9] http://goo.gl/VoZVYL Original: [10] http://goo.gl/5F61AX * Do companies ever hire someone who has no Haskell experience to be a Haskell programmer? If I pursue such a job, how important would a Domain: self.haskell, Score: 44, Comments: 50 On Reddit: [11] http://goo.gl/KA998k Original: [12] http://goo.gl/KA998k * [Haskell-cafe] PSA: do not install xcode 5 if you are using ghc 7.6 Domain: haskell.org, Score: 43, Comments: 4 On Reddit: [13] http://goo.gl/ut6k6p Original: [14] http://goo.gl/1G8Syo * Model Analysis - The New York Times’ Erik Hinton breaks down a Fashion Week special Domain: source.mozillaopennews.org, Score: 40, Comments: 4 On Reddit: [15] http://goo.gl/NdVw6l Original: [16] http://goo.gl/bYB8JS * Programming reactively with both barrels (experiences of Haskell/FRP for mobile games) Domain: blog.reactiveprogramming.org, Score: 39, Comments: 7 On Reddit: [17] http://goo.gl/QXacUo Original: [18] http://goo.gl/wLJwt6 * Why monads have not taken the Common Lisp world by storm [r/lisp] Domain: reddit.com, Score: 33, Comments: 14 On Reddit: [19] http://goo.gl/tZUVWx Original: [20] http://goo.gl/w5KHqc * 13,000 readers Domain: self.haskell, Score: 28, Comments: 11 On Reddit: [21] http://goo.gl/lTys0R Original: [22] http://goo.gl/lTys0R * A type for IO actions that do not throw exceptions Domain: self.haskell, Score: 25, Comments: 49 On Reddit: [23] http://goo.gl/Ao8HyB Original: [24] http://goo.gl/Ao8HyB * ANN: Scotty 0.5.0 Released Domain: github.com, Score: 24, Comments: 15 On Reddit: [25] http://goo.gl/jgGJhO Original: [26] http://goo.gl/BejPTF * Haskell version freezing Domain: blog.docmunch.com, Score: 23, Comments: 8 On Reddit: [27] http://goo.gl/9LJSjY Original: [28] http://goo.gl/Ikd86k * PHOAS For Free by Edward Kmett Domain: fpcomplete.com, Score: 21, Comments: 8 On Reddit: [29] http://goo.gl/RDt1BV Original: [30] http://goo.gl/o0phN7 * Cellular Automata, Part III by Edward Kmett Domain: fpcomplete.com, Score: 20, Comments: 0 On Reddit: [31] http://goo.gl/AKCfGw Original: [32] http://goo.gl/x7GtH1 * Translating Haskell programs to Coq [/Gallina] programs Domain: github.com, Score: 20, Comments: 2 On Reddit: [33] http://goo.gl/IQAp3K Original: [34] http://goo.gl/qcib77 * ANN: pipes-csv: a fast, streaming csv parser based on cassava and pipes Domain: github.com, Score: 20, Comments: 9 On Reddit: [35] http://goo.gl/aITtGX Original: [36] http://goo.gl/yrzZ7n Top StackOverflow Questions * What does the “Just” syntax mean in Haskell? votes: 12, answers: 4 Read on SO: [37] http://goo.gl/f17UEP * How can I understand “:t ((==) *)” in haskell? votes: 10, answers: 1 Read on SO: [38] http://goo.gl/CwyBn4 * why polymorphism is so costly in haskell(GHC)? votes: 10, answers: 3 Read on SO: [39] http://goo.gl/4MjcbH * Break and continue in GHCi debugger without use of breakpoints votes: 9, answers: 0 Read on SO: [40] http://goo.gl/HrtcXZ * Why is there no `-XDeriveApplicative` extension? votes: 8, answers: 1 Read on SO: [41] http://goo.gl/4dcRF1 * Downsides to ScopedTypeVariables votes: 7, answers: 2 Read on SO: [42] http://goo.gl/UjBcsg * Haskell design encompassing several monads votes: 7, answers: 1 Read on SO: [43] http://goo.gl/EwWd5d * How to correct my OOP tendencies when programming in Haksell votes: 7, answers: 3 Read on SO: [44]
[Haskell-cafe] Haskell Job Opportunity (Remote Work)
Hello, ShotVibe is an early-stage Israeli startup company in the mobile photo sharing space. We are looking for an experienced or expert level Haskell programmer for backend web related projects. The work will be done by you remotely, using a freelancer model, with the potential for longer term work in the near future (also remote). One of the projects we have is a server application that queues messages that are to be sent to end user mobile phones, and pushes them through the push notification APIs supplied by Google and Apple. The work needed here involves some bug fixes, and some new features. This project will likely eventually be open sourced. Another project that we need to be written from scratch is a web application that handles photo uploads and processes them (including verifying user authentication with our main web backend, image resizing, and storing images on Amazon S3). This will probably end up only a few hundred lines of Haskell code, but involves integrating a bunch of stuff together. We are also interested in experimenting in using Haskell for some other areas of our backend where we are currently using Python. If you are interested you may contact me at: be...@shotvibe.com Please feel free to forward this email to any friends or acquaintances that may be interested. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
