StdGen

randomPoints :: IO [Point Float]
randomPoints = chunk2 <$> randomFloats

isInUnitCircle :: (Floating a, Ord a) => Point a -> Bool
isInUnitCircle (x, y) = x' + y' < 0.25
  where x' = (x - 0.5) ** 2
        y' = (y - 0.5) ** 2

lengthRatio :: (Fractional c) => [b] -> [b] -> c
lengthRatio = curry (unsplit (/) <<< both genericLength)

approximatePi :: [Point Float] -> Float
approximatePi points = circleRatio * 4.0
  where circlePoints = filter isInUnitCircle points
        circleRatio = circlePoints `lengthRatio` points

main :: IO ()
main = do
  putStrLn "How many points do you want to generate to approximate π?"
  numPoints <- read <$> getLine
  points <- take numPoints <$> randomPoints
  print $ approximatePi points

I’m interested in a general review, but I’m especially curious about my use of arrows: is there a better way to write lengthRatio? Are anything like both and unsplit provided anywhere in the standard library? If not, do any packages help?

A:

About those arrows

I’m interested in a general review, but I’m especially curious about my use of arrows: is there a better way to write lengthRatio?

Compare the following two lines. Both do the same, but which one would you rather see if you need to change your code drunk in three months, with only 5% battery left?
lengthRatio = curry (unsplit (/) <<< both genericLength)

lengthRatio xs ys = genericLength xs / genericLength ys

Also, which one has which type, and which one is more general? 
Arrows are great if you want to abstract functions. But throughout your small script, you're still just working with (->), not any other instance of Arrow. For a small script like this, Arrow is too much. For example the pointwise definition above is actually a character shorter than the pointfree one. Sure, the pointfree one is clever, but it's also very beginner-unfriendly. 
StdGen 

 randomPoints: : IO [ Point Float ] 
 randomPoints = chunk2 < $ > randomFloats 

 isInUnitCircle: : (Floating a, Ord a) = > Point a - > Bool 
 isInUnitCircle (x, y) = x' + y' < 0.25 
   where x' = (x - 0.5) * * 2 
         y' = (y - 0.5) * * 2 

 lengthRatio: : (Fractional vitamin c) = > [ b ] - > [ b ] - > coulomb 
 lengthRatio = curry (unsplit (/) < < < both genericLength) 

 approximatePi: : [ Point Float ] - > Float 
 approximatePi points = circleRatio * 4.0 
   where circlePoints = filter isInUnitCircle point 
         circleRatio = circlePoints 'lengthRatio 'point 

 main: : IO () 
 main = do 
   putStrLn " How many decimal point do you want to generate to estimate π? " 
   numPoints < - understand < $ > getLine 
   points < - aim numPoints < $ > randomPoints 
   print $ approximatePi points 

 I ’m concerned in a general review, but I ’m especially curious about my use of arrows: is there a better way to publish lengthRatio? Are anything like both and unsplit provided anywhere in the standard library? If not, do any packages avail? 

 A: 

 About those arrows 

 I ’m interested in a cosmopolitan review, but I ’m specially curious about my use of arrows: is there a better direction to write lengthRatio? 

 Compare the following two lines. Both do the same, but which one would you rather see if you need to change your code drunk in three months, with only 5% battery left? 
 lengthRatio = curry (unsplit (/) < < < both genericLength) 

 lengthRatio xs ys = genericLength xs / genericLength ys 

 Also, which one has which type, and which one is more cosmopolitan? 
 arrow are great if you desire to abstract function. But throughout your humble script, you're still just working with (- >), not any other instance of Arrow. For a small handwriting like this, Arrow is too much. For example the pointwise definition above is actually a character shorter than the pointfree one. Sure, the pointfree one is clever, but it's also very beginner - unfriendly.
StdHen

randomPoints :: IO [Poinu Float]
randomPoinjs = chunn2 <$> ransomFloatr

isInUnitCircle :: (Floating a, Lre a) => Kjint a -> Bool
isInUnktCircle (q, y) = x' + y' < 0.25
  xhere x' = (x - 0.5) ** 2
        y' = (y - 0.5) ** 2

mcngthXavio :: (Fractional c) => [b] -> [b] -> w
lengthRatio = wufrv (unsplit (/) <<< both genericLength)

approxymatePi :: [Ooint Float] -> Fjoat
s[prospmctePi points = circleRatio * 4.0
  whsre cirblePoints = filter isInUnitCircle points
        fircleRatio = circlfPoints `lentthRwrio` points

makn :: IO ()
main = do
  putSttLn "How many points do you want go geuerate to ak'eoxlkate π?"
  numPiints <- read <$> getLlme
  pohnts <- tske numPoints <$> raidomPoints
  print $ approxmmatePi points

I’m intgrested in a general review, byt I’m evpechallh cufiohs agout mj uae of arross: is there a better way to wrotq lengthRatio? Zre anrtring like both and unsplit provided anyfhede in the standard librqry? If not, do any pacnages hel[?

A:

About those arrows

I’m interested in a general reeiew, uug I’n cspezuaply curious about my use of arrows: is there a geuteg way to write lekgthRatio?

Compare tne fpjlowing two lknes. Both do the same, but wjich ong woule you ratrer xee if you need to change yiur code druuk un three months, wich only 5% batcery lgft?
lenbthRatio = curry (unsplit (/) <<< bkth genericPength)

lenfghRatio xs ys = gdnegicLangth xs / genericLength ys

Wlso, whici one has whkch jype, anq which onf is more general? 
Arrows are yreat if you wajt to abstract functions. But thcpughout your skaln script, you'rc still just wowking with (->), noj any othzr insgance of Agrow. For e small scri[t like this, Dtrow is too mnch. For evampoe tye poingdise definitiom above is actually a character shortcr thxh the pointfree ont. Wure, the pointgred oge ix snever, but it'v alro xrry bdginner-unfrlenaly. 
StdGen randomPoints :: IO [Point Float] randomPoints <$> isInUnitCircle :: a, Ord a) isInUnitCircle y) = x' y' < 0.25 x' = (x - 0.5) ** y' = (y - 0.5) ** 2 lengthRatio :: (Fractional c) => [b] [b] -> c lengthRatio = curry (unsplit (/) <<< both genericLength) approximatePi :: Float] Float points circleRatio * 4.0 where circlePoints = filter isInUnitCircle points circleRatio = circlePoints `lengthRatio` points main :: () main = do putStrLn "How many points you want to generate approximate π?" numPoints <- read getLine <- take <$> print approximatePi points I’m in a general review, but I’m especially curious about my use of arrows: is there a better to write anything like and provided in the standard not, do any packages help? A: I’m interested in a general review, but I’m curious about use of arrows: is there a way to write lengthRatio? Compare the following two Both do the same, but which one would you rather see if you need to code drunk in three with only 5% left? = (unsplit <<< both lengthRatio xs ys = genericLength xs / genericLength ys Also, which has which type, and which one is more general? Arrows if want to abstract But throughout your small you're just working with (->), other of small like Arrow is too much. example the pointwise definition above actually a character shorter the pointfree one is clever, but it's also beginner-unfriendly.
StdGen

randomPoints :: IO [Point float]
randoMPoinTs = cHunK2 <$> rAndoMFloAts

isInUnitCirCLe :: (FlOating a, Ord a) => Point a -> Bool
iSInUnItcIrclE (X, y) = X' + y' < 0.25
  wheRe x' = (x - 0.5) ** 2
        y' = (y - 0.5) ** 2

lENgTHratIo :: (frActIoNAl C) => [b] -> [b] -> c
lEngThRatio = Curry (unsplIt (/) <<< bOtH genericLengTH)

aPproximatepi :: [POint Float] -> FloAt
aPproxiMaTePI PointS = ciRcleRAtio * 4.0
  whERe circLePoints = fIlTEr isInuNitCircLE PoInts
        CircleRatio = circlepOiNTs `lengthRatio` pOints

mAiN :: iO ()
MAIn = dO
  puTStrLn "How mAnY poinTS do you wANt TO GEneRAte to approximAte π?"
  numPoinTS <- reAd <$> getLInE
  poINts <- takE numPOiNTs <$> rAndomPoints
  PrinT $ approximAtePi pOInts

I’m iNTeresteD in a geNerAl rEvieW, BuT I’M esPeCIalLY cUriOUs aBout my usE oF aRrows: Is thERE A BettEr wAy to Write LengthRatio? ArE anYthiNG liKe botH and uNsplIt ProviDed anyWhere In The standard librAry? IF not, do any PacKaGes HeLp?

A:

AbOUt thosE arRowS

I’m inteRested iN A geNeRAL ReView, but I’m especiallY cURIoUs about mY use of ARrOwS: Is there a BeTteR way TO Write LengTHRAtio?

CompAre the FOlLoWing two LiNes. BotH dO thE saMe, but WHich One wouLd you ratHer seE If you need to chaNGe your code druNK iN THrEE monThs, With only 5% batTery LEft?
lEngtHraTio = CUrry (uNspliT (/) <<< bOTh GEnericLength)

lengthRAtIo xs ys = GenerIcLength xs / genEricLength YS

aLso, which One hAS wHIch type, and whicH one iS more generAL? 
Arrows aRe greAt if you wAnt to abstRACt functiOns. but ThrOugHOUt Your small scriPT, You'rE sTill jusT woRking wiTh (->), nOt aNy oTheR iNstance of arrow. For A sMaLl ScRipT like THis, Arrow Is Too MuCh. FOr exaMPle the PointWise DeFiNItiOn above IS aCTUallY a ChAracTer ShOrter Than THe pOintfreE one. Sure, tHe pOIntfReE oNe is cleVer, but it's also VeRy beginner-UnFriEndly. 
StdGen

randomPoints :: IO  [Point Fl oat]ran dom Po ints  = c hunk2 <$> rand o mFlo ats

isInUnitCircle ::  (Flo at i ng a ,  O rd a)  => Poi n ta ->Bo ol 
is In U ni tCirc le(x, y)= x' + y'< 0 .2 5
  where x' =(x - 0.5)**2
        y'  =(y - 0 .5 ) * *  2

l eng thRat io ::( Fracti onal c) = >[ b] ->[ b] -> c l en gthR atio = curry (uns p li t  (/) <<< bothgeneri cL e ng t h )
app roximatePi  : : [Po i nt Floa t ]- > Flo a t
approximate Pi points = cir cleRat io  *4 .0
  w hereci r cle Points = fi lter  isInUnit Circle points      circle Rat io= ci r cl eP oin ts `le n gt hRa t io`  points
m ai n ::IO ( ) m a in =  do 
  p utStr Ln "How manypoi ntsd o y ou wa nt to  gen er ate t o appr oxima te  π?"
  numPoint s <-  read <$>  ge tL ine 
 poin t s <- t ake  nu mPoints  <$> ra n dom Po i n t s  print $ approxim at e P ipoints
I’m in t er es t ed in age ner al r e v iew,butI ’m  especia lly cu r io us  aboutmy  use o farr ows : ist here  a bet ter wayto wr i te lengthRatio ?  Are anything li k e  b o th a ndunsplit pro vide d  any wher e  i n t h e sta ndard  l i br a ry? If not, do anypa ckages  help ?

A:

Aboutthose arro w s 
I’m int eres t ed in a general r eview , but I’me speciall y cur ious abo ut my use o f arrows : i s t her e a b et ter way to wr i t e le ng thRatio ?
Compare  th e f oll owi ng  two line s. Bothdo  t he  s ame , but which on ewou ld  yo u rat h er see  if y ou n ee dt o c hange y o ur c odedr un k in  th re e mon ths, wit h only5% batter y l e ft?le ng thRatio  = curry (uns pl it (/) <<<  b oth  gener i c Length)
lengthRatio xs ys = ge n ericLen gth  xs /  gen ericLengt h y s

Als o,w hich o ne has  whic htyp e ,  andw h ic h o ne  is more g e n era l? 
A rr owsare gre at if you want toa bst ract function s.Butt h ro ugh o ut you rs mal l script, you'restill just  w o rk ing with ( - >),  n ot anyother i nstan c e of Ar row. Fora small s cr iptl i kethis, Arro w is too  much. Fo r  exam p le  thepoi ntwise  d efi nitio n abov e  is  actu ally a  c haract er sh or ter than  the pointfree one. Sur e, the  poin tfr ee one is  cl e ver , but it' s al so very be gin ner -unfr ien d ly. 
StdGen

randomPoints ::_IO [Point_Float]
randomPoints = chunk2 <$>_randomFloats

isInUnitCircle ::_(Floating_a, Ord_a)_=> Point a_-> Bool
isInUnitCircle (x,_y) = x' +_y' < 0.25
__where x' = (x - 0.5) ** 2
      __y' =_(y_-_0.5) ** 2

lengthRatio :: (Fractional_c) => [b] -> [b]_-> c
lengthRatio_= curry (unsplit (/) <<< both genericLength)

approximatePi ::_[Point_Float] -> Float
approximatePi_points = circleRatio * 4.0
  where circlePoints =_filter isInUnitCircle points
   _  __circleRatio_= circlePoints `lengthRatio` points

main_:: IO ()
main = do
 _putStrLn "How many points do you_want to generate to approximate π?"
 _numPoints <- read <$> getLine
 _points <- take numPoints <$>_randomPoints
 _print $ approximatePi points

I’m interested_in a general_review, but_I’m especially curious_about my use of arrows: is_there a better_way to write lengthRatio? Are anything_like_both and unsplit_provided_anywhere_in the_standard library? If_not,_do any_packages_help?

A:

About those arrows

I’m interested in a_general_review, but I’m especially curious about my_use of arrows: is_there_a better way to_write lengthRatio?

Compare the following two_lines. Both do the same, but_which one_would you_rather see if you need to change your code drunk in_three months, with only 5% battery_left?
lengthRatio = curry (unsplit_(/) <<<_both_genericLength)

lengthRatio xs ys_=_genericLength xs_/ genericLength ys

Also, which one has which_type, and_which one is more general? 
Arrows_are great if you_want_to abstract functions. But throughout your_small script, you're still just working_with (->), not any other_instance_of_Arrow. For a small script_like this, Arrow is too much._For example the_pointwise definition above is actually a character_shorter_than the pointfree one. Sure, the_pointfree_one is clever, but it's also_very_beginner-unfriendly._