Grafikler temsil clojure

Question

Bir oyuncak NFA regexp matcher taşıyarak biraz clojure öğrenmeye çalışıyorum. Açıkçası benim ana meselem grafikleri temsil ediyor ve manipüle ediyor. Çalıştığım bir işe girdim, ancak benim uygulamam (temelde işaretçilerle öykünmek için gensym kullanıyordum) ağzımda çok tatlı bir tat bırakıyor.

Hem grafiklerin temsil edilmesi hem de genel okunabilirlik ve deyimler için iyileştirmeler önermek ister misiniz? (orijinal zorunlu çözüm, benim mevcut olandan çok daha okunabilir).

Şerefe! onlar görünür ProgID geliştirme ve kolayca sorunun bu tip yararlı bulabilirsiniz hangi zipper library kullanılarak manipüle edilebilir, çünkü

; This is a port of Matt Might's toy regexp library described in 
; http://matt.might.net/articles/implementation-of-nfas-and-regular-expressions-in-java/ 

; char_transitions is a map that associates a character with a set 
; of target state names 
; empty_transitions is a set of target state names 
(defrecord NfaState [final char_transitions empty_transitions]) 

; 'entry' and 'exit' are state names 
; 'states' is a map that associates state names with states 
(defrecord Nfa [entry exit states]) 

(defn- add-empty-edge [nfa curr_state_name next_state_name] 
    (let [curr_state (curr_state_name (:states nfa))] 
    (Nfa. (:entry nfa) (:exit nfa) (assoc (:states nfa) curr_state_name (NfaState. (:final curr_state) (:char_transitions curr_state) (conj (:empty_transitions curr_state) next_state_name)))))) 

(defn- nfa-matches? 
    ([nfa nfa_state_name string] (nfa-matches? nfa nfa_state_name string #{})) 
    ([nfa nfa_state_name string visited] 
    (let [nfa_state (nfa_state_name (:states nfa)) 
     new_visited (conj visited nfa_state_name)] 
    (cond 
     (contains? visited nfa_state_name) false 
     (empty? string) (or (:final nfa_state) 
          (some #(nfa-matches? nfa % string new_visited) 
           (:empty_transitions nfa_state))) 
     (not (empty? string)) (or 
           (some #(nfa-matches? nfa % (.substring string 1)) (get (:char_transitions nfa_state) (.charAt string 0) #{})) 
           (some #(nfa-matches? nfa % string new_visited) (:empty_transitions nfa_state))) 
     :else false)))) 

(defn matches? [nfa string] 
    "Matches a string against an NFA" 
    (nfa-matches? nfa (:entry nfa) string)) 

(defn c [ch] 
    "Creates an NFA which matches the character 'c'" 
    (let [in (gensym) 
     out (gensym)] 
    (Nfa. in out {in (NfaState. false {ch #{out}} #{}) out (NfaState. true {} #{})}))) 

(defn e [] 
    "Creates an NFA which matches the empty string" 
    (let [in (gensym) 
     out (gensym)] 
    (Nfa. in out {in (NfaState. false {} #{out}) out (NfaState. true {} #{})}))) 

(defn rep [nfa] 
    "Creates an NFA which matches zero or more repetitions of the given NFA" 
    (add-empty-edge (add-empty-edge nfa (:entry nfa) (:exit nfa)) (:exit nfa) (:entry nfa))) 

(defn- update-final [nfastate new_final] 
    (NfaState. new_final (:char_transitions nfastate) (:empty_transitions nfastate))) 

(defn s [first second] 
    "Creates an NFA which matches a sequence of two provided NFAs" 
    (add-empty-edge (Nfa. (:entry first) (:exit second) (merge (update-in (:states first) [(:exit first)] update-final false) (update-in (:states second) [(:exit second)] update-final true))) (:exit first) (:entry second))) 

(defn ou [first second] 
    "Creates an NFA which matches either provided NFA" 
    (let [in (gensym) 
     out (gensym)] 
    (add-empty-edge (add-empty-edge (Nfa. in out (assoc (merge (update-in (:states first) [(:exit first)] update-final false) (update-in (:states second) [(:exit second)] update-final false)) in (NfaState. false {} #{(:entry first) (:entry second)}) out (NfaState. true {} #{}))) (:exit first) out) (:exit second) out))) 

; sugar 
(defn st [string] 
    "Creates an NFA which matches the provided string" 
    (if (empty? string) 
    (e) 
    (s (c (.charAt string 0)) (st (.substring string 1))))) 

Answer 1

Harita ve setleri mükemmel veriler, yapıları vardır.