dylan: mtg/bk.clj annotate

annotate mtg/bk.clj @ 2:b4de894a1e2e

initial import

author	Robert McIntyre <rlm@mit.edu>
date	Fri, 28 Oct 2011 00:03:05 -0700
parents
children

rev	line source
rlm@2	1 (ns mtg.frame)
rlm@2	2
rlm@2	3 ;; GENERALLY USEFUL FUNCTIONS
rlm@2	4
rlm@2	5 (defn assay "Takes x and a series of pred-value pairs. Returns a list of vals for which the corresponding preds are true of x." [x & pred-vals]
rlm@2	6 (reduce #(if ((first %2) x) (conj %1 (second %2))) '() pred-vals)
rlm@2	7 )
rlm@2	8 (defn alter-val "Applies f to the current value associated with each key, associating each key with the value returned." [m f & keys]
rlm@2	9 (map #(assoc m % (f (get m %))) keys))
rlm@2	10
rlm@2	11 (defn every-nth "Returns every nth member of coll. If n is not positive, returns an empty list." [n coll]
rlm@2	12 (if (<= n 0) '()
rlm@2	13 (take-while (comp not nil?) (map first (iterate #(nthnext % n) coll)))))
rlm@2	14
rlm@2	15
rlm@2	16
rlm@2	17
rlm@2	18
rlm@2	19 ;; FRAME MANIPULATION
rlm@2	20
rlm@2	21
rlm@2	22 (defn conj-key "Adds the xs to the seq associated with the given key." [map key & xs]
rlm@2	23 (assoc map key (apply conj (get map key []) xs)))
rlm@2	24
rlm@2	25 (defn update "Takes a frame and a sequence of key-fn pairs. Applies f to the current value associated with key, updating the current value with the result. Frames generate and store a unique id for each call to update."
rlm@2	26 [frame & kfs]
rlm@2	27 (let [id (gensym "up_")
rlm@2	28 keys (every-nth 2 kfs)
rlm@2	29 fns (every-nth 2 (rest kfs))]
rlm@2	30
rlm@2	31 ((reduce comp (map (fn[k f](fn[m](conj-key m k (list id f) )) keys fns))
rlm@2	32 (conj-key frame :bindings (map (fn [k f](list id k)) keys fns))
rlm@2	33 )
rlm@2	34 ))
rlm@2	35
rlm@2	36
rlm@2	37
rlm@2	38
rlm@2	39 (def frame (atom {:bindings '()}))

Mercurial > dylan

annotate mtg/bk.clj @ 2:b4de894a1e2e