Idiosyncratic Ruby: Ruby TRICKS of 2015

Ruby was initially designed to be a successor of the Perl programming language, which also means that it inherited a lot of Perl's expressiveness. To celebrate this, the TRIC¹ contest was invented:

Write the most Transcendental, Imbroglio Ruby program!
Illustrate some of the subtleties (and design issues) of Ruby!
Show the robustness and portability of Ruby interpreters!
Stabilize the spec of Ruby by the presence of valuable but unmaintainable code!

The best submissions were awarded at the Japanese Ruby Kaigi conference and also included in the Ruby source, for educational purpose. The winning submissions² of 2015 were:

¹ Transcendental Ruby Imbroglio Contest
² All code is MIT licensed, Copyright (c) 2015, TRICK Winners and Judges

1st Place: "Best piphilology"

By kinaba (remarks)

big, temp = Array 100000000**0x04e2
srand big
alias $curTerm $initTerm

Numeric
Interrupt

big += big
printout _pi_ finish if $never
init ||= big
$counter ||= 02

private
@mainloop
while 0x00012345 >= $counter

  Rational aprx = 3.141592r
  numbase = 0o0000

  @justonce
  def increment
    $initTerm ||= Integer srand * 0x00000002
    srand $counter += 0x00000001

    $noaction
    Integer rand
    $noaction
    rand
    rand
    alias $line_cnt $.
  end

  @lets_just
  @assume
  diameter = 100000

  @you
  @then_have
  permtr |= +3_14159

  return if $nomeaning

  @onlyuse
  increment

  beautiful computer action if $nothing
  $sigmaTerm ||= init
  $curTerm /= srand and init
  pi, = Integer $sigmaTerm unless $nomean

  iterator?
  $counter += 1
  atan real_one multiplied by__four unless
  srand +big && $counter >> 0b1

  Enumerable
  Fixnum
  Bignum
  Math
  Complex
  Comparable
  TrueClass
  Dir
  Encoding
  Data
  Hash
  Method
  Enumerator
  Exception
  Fiber
  Errno
  FalseClass
  Mutex
  NilClass
  IO
  GC

  num = numbase |= srand

  ENV
  Float
  MatchData
  Proc
  TracePoint
  KeyError
    p   or
  FileTest
  File
  EOFError
    p
    p
    p
  Binding
  Time
  Class

  $sigmaTerm += $curTerm
  puts a HelloWorld if $nomean
  SystemExit

  !LoadError
  31i
  3.1415e0
  Array 14 + 3
  IndexError
  Range
  false
  55555
  NameError

  Object
  @ori
    @ent
  RubyVM

  pi += 3_3_1_3_8

  @use
  @lots_of
  @keywords
  begin
    self
    $noaction
    not $important
    nil
    __FILE__.object_id
  rescue
    next
    redo if __LINE__
    defined? +$nomeaning
    $noaction
    $nomean
    break $never
  ensure
    class PiCompute
    end
  end

  This code cannot _ be executed with typical style unless true
  $curTerm *= num
end

@ll_set
@re_U_ok

$Enjoy
$Superb
$TRICK15 and a number

print pi

All valid syntax! Run it and it will output the first 1000 digits of Pi:

31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989380952572010654858632788659361533818279682303019520353018529689957736225994138912497217752834791315155748572424541506959508295331168617278558890750983817546374649393192550604009277016711390098488240128583616035637076601047101819429555961989467678374494482553797747268471040475346462080466842590694912933136770289891521047521620569660240580381501935112533824300355876402474964732639141992726042699227967823547816360093417216412199245863150302861829745557067498385054945885869269956909272107975093029553211653449872027559602364806654991198818347977535663698074265425278625518184175746728909777727938000816470600161452491921732172147723501414419735685481613611573525521334757418494684385233239073941433345477624168625189835694855620992192221842725502542568876717904946016534668049886272327917860857843838279679766814541009538837863609506800642251252051173929848960841284886269456042419652850222106611863067442786220391949450471237137869609563643719172874677646575739624138908658326459958133904780275900994657640789512694683983525957098258226205224894077267194782684826014769909026401363944374553050682034962524517493996514314298091906592509372216964615157098583874105978859597729754989301617539284681382686838689427741559918559252459539594310499725246808459872736446958486538367362226260991246080512438843904512441365497627807977156914359977001296160894416948685558484063534220722258284886481584560285060168427394522674676788952521385225499546667278239864565961163548862305774564980355936345681743241125150760694794510965960940252288797108931456691368672287489405601015033086179286809208747609178249385890097149096759852613655497818931297848216829989487226588048575640142704775551323796414515237462343645428584447952658678210511413547357395231134271661021359695362314429524849371871101457654035902799344037420073105785390621983874478084784896833214457138687519435064302184531910484810053706146806749192781911979399520614196634287544406437451237181921799983910159195618146751426912397489409071864942319615679452080951465502252316038819301420937621378559566389377870830390697920773467221825625996615014215030680384477345492026054146659252014974428507325186660021324340881907104863317346496514539057962685610055081066587969981635747363840525714591028970641401109712062804390397595156771577004203378699360072305587631763594218731251471205329281918261861258673215791984148488291644706095752706957220917567116722910981690915280173506712748583222871835209353965725121083579151369882091444210067510334671103141267111369908658516398315019701651511685171437657618351556508849099898599823873455283316355076479185358932261854896321329330898570642046752590709154814165498594616371802709819943099244889575712828905923233260972997120844335732654893823911932597463667305836041428138830320382490375898524374417029132765618093773444030707469211201913020330380197621101100449293215160842444859637669838952286847831235526582131449576857262433441893039686426243410773226978028073189154411010446823252716201052652272111660396665573092547110557853763466820653109896526918620564769312570586356620185581007293606598764861179104533488503461136576867532494416680396265797877185560845529654126654085306143444318586769751456614068007002378776591344017127494704205622305389945613140711270004078547332699390814546646458807972708266830634328587856983052358089330657574067954571637752542021149557615814002501262285941302164715509792592309907965473761255176567513575178296664547791745011299614890304639947132962107340437518957359614589019389713111790429782856475032031986915140287080859904801094121472213179476477726224142548545403321571853061422881375850430633217518297986622371721591607716692547487389866549494501146540628433663937900397692656721463853067360965712091807638327166416274888800786925602902284721040317211860820419000422966171196377921337575114959501566049631862947265473642523081770367515906735023507283540567040386743513622224771589150495309844489333096340878076932599397805419341447377441842631298608099888687413260472156951623965864573021631598193195167353812974167729478672422924654366800980676928238280689964004824354037014163149658979409243237896907069779422362508221688957383798623001593776471651228935786015881617557829735233446042815126272037343146531977774160319906655418763979293344195215413418994854447345673831624993419131814809277771038638773431772075456545322077709212019051660962804909263601975988281613323166636528619326686336062735676303544776280350450777235547105859548702790814356240145171806246436267945612753181340783303362542327839449753824372058353114771199260638133467768796959703098339130771098704085913374641442822772634659470474587847787201927715280731767907707157213444730605700733492436931138350493163128404251219256517980694113528013147013047816437885185290928545201165839341965621349143415956258658655705526904965209858033850722426482939728584783163057777560688876446248246857926039535277348030480290058760758251047470916439613626760449256274204208320856611906254543372131535958450687724602901618766795240616342522577195429162991930645537799140373404328752628889639958794757291746426357455254079091451357111369410911939325191076020825202618798531887705842972591677813149699009019211697173727847684726860849003377024242916513005005168323364350389517029893922334517220138128069650117844087451960121228599371623130171144484640903890644954440061986907548516026327505298349187407866808818338510228334508504860825039302133219715518430635455007668282949304137765527939751754613953984683393638304746119966538581538420568533862186725233402830871123282789212507712629463229563989898935821167456270102183564622013496715188190973038119800497340723961036854066431939509790190699639552453005450580685501956730229219139339185680344903982059551002263535361920419947455385938102343955449597783779023742161727111723643435439478221818528624085140066604433258885698670543154706965747458550332323342107301545940516553790686627333799585115625784322988273723198987571415957811196358330059408730681216028764962867446047746491599505497374256269010490377819868359381465741268049256487985561453723478673303904688383436346553794986419270563872931748723320837601123029911367938627089438799362016295154133714248928307220126901475466847653576164773794675200490757155527819653621323926406160136358155907422020203187277605277219005561484255518792530343513984425322341576233610642506390497500865627109535919465897514131034822769306247435363256916078154781811528436679570611086153315044521274739245449454236828860613408414863776700961207151249140430272538607648236341433462351897576645216413767969031495019108575984423919862916421939949072362346468441173940326591840443780513338945257423995082965912285085558215725031071257012668302402929525220118726767562204154205161841634847565169998116141010029960783869092916030288400269104140792886215078424516709087000699282120660418371806535567252532567532861291042487761825829765157959847035622262934860034158722980534989650226291748788202734209222245339856264766914905562842503912757710284027998066365825488926488025456610172967026640765590429099456815065265305371829412703369313785178609040708667114965583434347693385781711386455873678123014587687126603489139095620099393610310291616152881384379099042317473363948045759314931405297634757481193567091101377517210080315590248530906692037671922033229094334676851422144773793937517034436619910403375111735471918550464490263655128162288244625759163330391072253837421821408835086573917715096828874782656995995744906617583441375223970968340800535598491754173818839994469748676265516582765848358845314277568790029095170283529716344562129640435231176006651012412006597558512761785838292041974844236080071930457618932349229279650198751872127267507981255470958904556357921221033346697499235630254947802490114195212382815309114079073860251522742995818072471625916685451333123948049470791191532673430282441860414263639548000448002670496248201792896476697583183271314251702969234889627668440323260927524960357996469256504936818360900323809293459588970695365349406034021665443755890045632882250545255640564482465151875471196218443965825337543885690941130315095261793780029741207665147939425902989695946995565761218656196733786236256125216320862869222103274889218654364802296780705765615144632046927906821207388377814233562823608963208068222468012248261177185896381409183903673672220888321513755600372798394004152970028783076670944474560134556417254370906979396122571429894671543578468788614445812314593571984922528471605049221242470141214780573455105008019086996033027634787081081754501193071412233908663938339529425786905076431006383519834389341596131854347546495569781038293097164651438407007073604112373599843452251610507027056235266012764848308407611830130527932054274628654036036745328651057065874882256981579367897669742205750596834408697350201410206723585020072452256326513410559240190274216248439140359989535394590944070469120914093870012645600162374288021092764579310657922955249887275846101264836999892256959688159205600101655256375678

But that is not all, Pi is encoded a second time! The program is a Piphilology: Each token's length represents the next digit (and 0 is represented by a token length of 10)! Save the program as entry.rb and run the following one-liner to verify:

$ ruby -r ripper -e \
  'puts Ripper.tokenize(STDIN).grep(/\S/).map{|t|t.size%10}.join' < entry.rb

Output:

31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652

2nd Place: "Most unreadable ALU"

By Keisuke Nakano (remarks)

If the number is even, divide it by two, otherwise, multiply it by three and add one. …and eventually the number becomes 1. This is known as the Collatz conjecture. The following one-liner calculates this series, without using any conditionals or arithmetic operations:

%%%while eval '_=%%r%%(.)...\1=%%=~[%%%%,,,,,%%%s  ?=]*%%%%%%#"]*%%%%3x+1?%%'.% %%",%*p(_||=eval($**%%%))

To try it out, save the code to entry.rb and called it with a number! Example of $ ruby entry.rb 42:

3rd Place: "Doubling amphisbaena award"

By monae (remarks)

          ;;  ;;          ;;  ;;
           ;;  ;;          ;;  ;;
        ;;eval$s        =%q[i=1#
         eval(%q[        xxxxxxxx
        xx  xxxx  xx    xx  xxxx  xx
         xx  xxxx  xx    xx  xxxx  xx
            xxxxxxxx        xxxxxxxx
             xxxxxxxx        xxxxxxxx
  xx  xx  xxxxxxxxxx  xx  xxxxxxxx
   j,  t,  p=0,[?;],"  ev  al$s=%qx
[#$s]".split*"";i,j,t=i-j,i+j,(x
 [b=?\s]*j.abs+t).map{|s|r=t.shix
ft  ||b;r.gsub!(?;){p.slice!0}if  $x
 f|  |=p>p=p.center(i*i+j*j,?;);r  ,x
    s=[s,r]if(i*j<0);(b*i.abs+s).ljx
     ust(r.size).gsub(b){r[$`.size]|x
  |b}}unti  l$  f;puts(t)#  xx  xx
   xxxxxxxx  xx  xxxxxxxxxx  xx  xx
xxxxxxxx        xxxxxxxx
 xxxxxxxx        xxxxxxxx
xx  xxxx  xx    xx  xxxx  xx
 xx  xxxx  xx    xx  xxxx  xx
    xxxxxxxx        x].gsub\
     /x.*|\s/        ,"")#];;
    ;;  ;;          ;;  ;;
     ;;  ;;          ;;  ;;

Save this program as entry.rb and run it with:

$ ruby entry.rb | ruby | ruby | ruby # ...

Then watch it duplicating!

4th Place: "Least general solver"

By Benoit Daloze (remarks)

What is your visual impression when looking at the following code?

class String;def[]*a;$*<<a;b;end;end;
_=0;z="C=Fiber;s=$*;a=*0..8;l=C.new{e
xit},*a.product(a).select{|r,c|s[r][c
]==0}."[1,9,_, _,_,8, _,_,5]+"map{|r,
 c|C.ne"[_,_,2, _,5,_, _,8,9]+"w{o=s[r
][c];l"[8,_,6, 7,4,_, _,_,_]+"oop{(1.
.9).map{|n|C.yield(s[r][c]=n)if a.non
e?{|k|"[_,_,_, _,_,4, _,9,2]+"s[r][k]
==n||s"[_,2,3, _,7,_, 8,1,_]+"[k][c]=
=n||s["[5,6,_, 8,_,_, _,_,_]+"r-r%3+k
%3][c-c%3+k/3]==n}};s[r][c]=o;C.yield
}}},C."[_,_,_, _,2,7, 9,_,3]+"new{loo
p{puts"[9,3,_, _,8,_, 1,_,_]+" s.map{
|r|r*'"[2,_,_, 5,_,_, _,4,8]+" '}<<''
;C.yield}};c=l[i=1];loop{c=l[i+=c.res
ume ? 1:-1]}";eval z.tr ?\n,''

There is a Sudoku embedded! Run the code to solve it!

5th Place: "Most general solver"

By Keisuke Nakano (remarks)

This handy one-liner is a SAT solver based on Ruby's regex engine:

_='s %sSATISFIABLE';puts eval$<.read.gsub(/.*p.*?(\d+).*?$|\d+/m){$1?%w[?-* +'=-'=~/#{'(-?)'* }-*=(?=]*$1:$&>?0?"\\#$&$|":'$)(?='}+')/x?[_%p%i=0,[*$~].map{|x|x>?-?:v:eval(x+?1)*i-=1}*" "]:_%:UN'

See the description for more info! Sample files to pipe in:

Other Awarded Submissions

"Most Beautiful Pattern" (yhara award) by Shinichiro Hamaji (remarks)
"Most Fragile" (shinh award) by NAKAMURA Usaku (remarks)
"Matz Lisp Award" (matz award) by Kazuki Tsujimoto (remarks)
"Most Timely" (mame award) by Koichi Sasada (remarks)
"Best Document" (eban award) by yoshi-taka (remarks)
"Most Illusionistic" (eto award) by Don Yang (remarks)
"Most Inconsistent" (leonid award) by Koichi Sasada (remarks)

Ruby TRICKS of 2015