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Today's Topics:
1. Re: Debugging in Haskell (m00nlight)
2. Re: Debugging in Haskell (Henk-Jan van Tuyl)
3. Re: Need help to write join on my Temporals (martin)
4. Linebreaks in lhs2tex eval (martin)
----------------------------------------------------------------------
Message: 1
Date: Sun, 12 Apr 2015 14:16:14 +0800 (CST)
From: m00nlight <[email protected]>
To: "The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell" <[email protected]>
Subject: Re: [Haskell-beginners] Debugging in Haskell
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
Emacs can be configured to look great, see the following quora answer for
example. You can just try to get used to it and
add your configuration incremently. After a few time, it will be of beautiful
appearance.
http://www.quora.com/How-can-I-go-from-good-to-great-in-Emacs
--m00nlight
?2015?04?10 08?18?, "Dimitri DeFigueiredo"<[email protected]>??:
I did try to use Leksah, but did not like the interface. I don't
think it helped with debugging, but may be mistaken. I'm now using sublime
3 and hoping that someday I will be able to use Atom. Emacs appears to be
the standard, but it is just too ugly for me.
Dimitri
On 09/04/15 02:03, emacstheviking wrote:
That's interesting.
I must confess that I find the need to debug in Haskell
greatly reduced because I tend to design stuff in small incremental
steps in ghci / emac in a Lisp like way which means that I am
reasoning out my code as I write it which usually means there are no
logical bugs at least.
However I can see the need on occasion to maybe debug into issues
relating to threads / STM and behaviours between processes in general.
Have you tried using Leksah, the Haskell IDE?
On 9 April 2015 at 02:21, Dimitri DeFigueiredo
<[email protected]> wrote:
I need to improve my Haskell debugging skills. I know of
quickcheck, but that's for testing. It seems that:
- Debug.Trace and
- dynamic breakpoints in GHCi
Are the two easy ways to check the state of your program at
a specific point in execution.
Is there another simple tool that I should know about? Any
tips?
Thank you,
Dimitri
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Message: 2
Date: Sun, 12 Apr 2015 11:09:25 +0200
From: "Henk-Jan van Tuyl" <[email protected]>
To: "The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell" <[email protected]>,
"Dimitri DeFigueiredo" <[email protected]>
Subject: Re: [Haskell-beginners] Debugging in Haskell
Message-ID: <op.xwy2d4mnpz0j5l@alquantor>
Content-Type: text/plain; charset=iso-8859-15; format=flowed;
delsp=yes
On Thu, 09 Apr 2015 03:21:05 +0200, Dimitri DeFigueiredo
<[email protected]> wrote:
> I need to improve my Haskell debugging skills. I know of quickcheck, but
> that's for testing. It seems that:
>
> - Debug.Trace and
> - dynamic breakpoints in GHCi
>
> Are the two easy ways to check the state of your program at a specific
> point in execution.
> Is there another simple tool that I should know about? Any tips?
GHC 7.10 can generate debug information, see the Release notes for version
7.10.1 [0].
Regards,
Henk-Jan van Tuyl
[0]
https://downloads.haskell.org/~ghc/7.10.1/docs/html/users_guide/release-7-10-1.html
--
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http://folding.stanford.edu/
http://Van.Tuyl.eu/
http://members.chello.nl/hjgtuyl/tourdemonad.html
Haskell programming
--
------------------------------
Message: 3
Date: Sun, 12 Apr 2015 11:49:13 +0200
From: martin <[email protected]>
To: [email protected]
Subject: Re: [Haskell-beginners] Need help to write join on my
Temporals
Message-ID: <[email protected]>
Content-Type: text/plain; charset=windows-1252
So I have a solution now, it passes my tests but it is ugly. While I am
unnesting I sometimes have to add the default as
a new change and sometimes add the last old change with its time advanced.
The problem is, I don't really know the semantics of a Temporal Temporal, but I
know the semantics of <*> and that <*>
must be the same as `ap`.
Any comments will be very welcome.
-- cBetween :: Time -> Time -> [Change a] -> [Change a]
-- cAfter :: Time -> [Change a] -> [Change a]
-- cBefore :: Time -> [Change a] -> [Change a]
tJoin :: Temporal (Temporal a) -> Temporal a
tJoin (Temporal tdef []) = tdef
tJoin tp@(Temporal tdef ctps)
| null cs' = Temporal (td tdef) (tj ctps)
| otherwise = Temporal (td tdef) (cs' ++ tj' ctps)
where
cs = tc tdef
cs' = cBefore (ct $ head ctps) cs
tj, tj' :: [Change (Temporal a)] -> [Change a]
-- before first change was found
tj ((Chg t (Temporal d [])):[]) = [Chg t d]
tj ((Chg t (Temporal d cs)):[]) = preDef t d cs (cAfter t cs)
tj ((Chg t (Temporal d [])):cts) = (Chg t d) : (tj cts)
tj ((Chg t (Temporal d cs)):cts)
| null cs' = preDef t d cs (tj cts)
| otherwise = preDef t d cs cs' ++ (tj' cts)
where
cs' = cBetween t (ct $ head cts) cs
-- after first change was found
tj' ((Chg t (Temporal d cs)):[]) = preC0 t cs (cAfter t cs)
tj' ((Chg t (Temporal d cs)):cts) = preC0 t cs cs' ++ (tj' cts)
where
cs' = cBetween t (ct $ head cts) cs
-- prepend first change if required
preC0 t cs cs'
| null bef = cs'
| tx == t = cs'
| otherwise = (Chg t vx) : cs'
where
bef = cBefore' t cs
(Chg tx vx) = last bef
-- prepend default as new change
preDef t d cs cs'
| null cs = cs'
| t == tx = cs'
| otherwise = (Chg t d) : cs'
where
(Chg tx vx) = head cs
Am 04/10/2015 um 07:02 PM schrieb martin:
> type Time = Integer
> data Change a = Chg {
> ct :: Time, -- "change time"
> cv :: a -- "change value"
> } deriving (Eq,Show)
>
> data Temporal a = Temporal {
> td :: a, -- "temporal default"
> tc :: [Change a] -- "temporal changes"
> } deriving (Eq, Show)
------------------------------
Message: 4
Date: Sun, 12 Apr 2015 13:55:45 +0200
From: martin <[email protected]>
To: [email protected]
Subject: [Haskell-beginners] Linebreaks in lhs2tex eval
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8
Hello all,
it appears lhs2tex's \eval command does not show linebreaks. This is a pity,
particularly when the output is formatted
with a pretty printer.
Is there a way to teach \eval to respect the linebreaks?
------------------------------
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