cascalog.drake

; http://nathanmarz.com/blog/introducing-cascalog-a-clojure-based-query-language-for-hado.html
;
; Run with method executing a script:
;   drake -w cascalog.drake %playground
;
; Run with code eval:
;   drake -w cascalog.drake %playground.eval
;
CASCALOG_JAR:=$[HOME]/local/bin/cascalog-standalone.jar

file() [eval]
  echo "$CODE" | tee $OUTPUT | nl

cascalog_file() [eval]
  java -jar $[CASCALOG_JAR] $INPUT

cascalog_code() [eval]
  java -jar $[CASCALOG_JAR] -e "$CODE"

;
; load playground data 
;
playground.clg <- [method:file method-mode:append]
  (use 'cascalog.playground) (bootstrap)
  (?<- (stdout) [?person] (age ?person 25))

%playground <- playground.clg [method:cascalog_file]

%playground.eval <- [eval]
  java -jar $[CASCALOG_JAR] -e "$CODE"
  (use 'cascalog.playground) (bootstrap)
  (?<- (stdout) [?person] (age ?person 25))

;
; cascalog tutorial: 
;   http://cascalog.org/articles/getting_started.html
;
;   http://nathanmarz.com/blog/introducing-cascalog-a-clojure-based-query-language-for-hado.html
;   http://nathanmarz.com/blog/new-cascalog-features-outer-joins-combiners-sorting-and-more.html
;   https://www.youtube.com/watch?v=7qq_PmwplEc
;
;cascalog_tutorial.clg <- [method:file method-mode:append]
cascalog_tutorial.clg <- [method:cascalog_code method-mode:append]
  (use 'cascalog.playground) (bootstrap)
  ; print dataset 
  (?- (stdout) sentence)
  (?- (stdout) follows)
  ; sentence by line
  (?- (stdout) 
    (<- [?line] (sentence :> ?line))
  )
  ; take 2 tuples
  (take 2 person)
  (take 2 age)
  (take 2 gender)
  ; define tokenize cascalog operation
  (require '[cascalog.logic.def :as def])
  (def/defmapcatfn tokenise [line]
    "reads in a line of string and splits it by a regular expression"
    (clojure.string/split line #"[\[\]\\\(\),.)\s]+")) 
  ; tokenize sentence
  (?- (stdout)
    (<- [?word]
      (sentence :> ?line)
      (tokenise :< ?line :> ?word)))
  ; Aggregation
  (require '[cascalog.logic.ops :as c])
  (?- (stdout)
    (<- [?word ?count]
      (sentence :> ?line)
      (tokenise :< ?line :> ?word)
      (c/count :> ?count)
    ))
  ; inner join
  (?<- (stdout) [?person ?age ?gender]
    (age ?person ?age)
    (gender ?person ?gender)
  )
  ; outer join
  (?<- (stdout) [?person !!age !!gender]
    (age ?person !!age)
    (gender ?person !!gender)
  )
  ;
  (?<- (stdout) [?person1 !!person2]
    (person ?person1)
    (follows ?person1 !!person2))
  (?<- (stdout) [?person]
    (person ?person)
    (follows ?person !!p2)
    (nil? !!p2))

;
; running on a cluster:
;  http://nathanmarz.com/blog/news-feed-in-38-lines-of-code-using-cascalog.html
; with swank
;  https://groups.google.com/forum/#!topic/cascalog-user/T3aoOTlBb6s
;
%demo <-
  (use 'cascalog.api)
  (require '[cascalog [vars :as v] [ops :as c]])
  (?<- (stdout) (hfs-textline "PATH"))

;
; https://github.com/nathanmarz/cascalog-workshop
;
%cascalog_workshop <-

;
; a cascalog excercise: https://github.com/sritchie/climate-class
;
%climate_class <-


;
; a cascalog excercise: 
;   https://github.com/sthuebner/cascalog-examples
;   http://vimeo.com/48349618
;
%cascalog_examples <-


;
; form-clj for image processing in cascalog
;   https://github.com/wri/forma-clj
;
forma_clj <-

;
; pagerank 
;   https://github.com/docteurZ/cascalog-contrib/blob/pagerank/cascalog.graph/src/cascalog/graph/pagerank.clj
;
pagerank <-

;
; cascalog for graph processing:
;   http://www.rene-pickhardt.de/nils-grunwald-from-linkfluence-talks-at-fosdem-about-cascalog-for-graph-processing/
;
graph <-

;
; http://blog.factual.com/clojure-on-hadoop-a-new-hope
; https://github.com/chunhk/cascalog-hope
; 
cascalog_hope <-