setTimeout -> core.async + handle cases where there are lots of answers

resources/public/prolog-dbg.html

@@ -95,7 +95,15 @@
  <div class="query">
 brother(X, Y).
  </div>
- <br/>
+ <br/>
+ <div class="rules">
+ numeral(0).
+ numeral(succ(X)) :- numeral(X).
+ </div>
+ <div class="query">
+ numeral(X).
+ </div>
+
 
  <div class="rules">
 :- use_module(library(dom)).

src/klipse/lang/prolog.cljs

@@ -1,11 +1,11 @@
 (ns klipse.lang.prolog
  (:require-macros
- [gadjett.core :refer [dbg my-with-redefs]]
+ [gadjett.core :refer [dbg]]
  [purnam.core :refer [!> ?]]
- [cljs.core.async.macros :refer [go]])
+ [cljs.core.async.macros :refer [go go-loop]])
  (:require
  [clojure.string :as string]
- [cljs.core.async :refer [chan put!]]
+ [cljs.core.async :refer [chan put! timeout]]
  [klipse.utils :refer [runonce]]
  [klipse.common.registry :refer [codemirror-mode-src register-mode]]))
 
@@ -35,39 +35,49 @@
  (put! c (str o))))
  c))
 
-(defn query* [exp]
- (let [my-session @session
- res (!> my-session.query exp)]
+(defn query* [thread exp]
+ (let [res (!> thread.query exp)]
  (if (= true res)
  [:ok true]
  [:error (str res)])))
 
-(defn answer* [cnt num-solutions callback]
- (let [my-session @session]
- (!> my-session.answer
- (fn [ans]
- (case ans
- false (if (zero? num-solutions)
- (callback "No solutions.")
- (callback (str "Found " num-solutions " solutions.")))
- nil (js/setTimeout
- #(do
- (callback {:data (str num-solutions " solutions after " (* (inc cnt) 1000) " tries. Continuing to try...\n")
- :remove-previous-results true})
- (answer* (inc cnt) num-solutions callback))
- 100)
+(defn pl-answer [thread]
+ (let [c (chan)]
+ (!> thread.answer (fn [answer]
+ (put! c (if (nil? answer) "nil" answer))))
+ c))
+
+(defn answer* [thread c]
+ (go-loop [cnt 0
+ num-solutions 0]
+ (let [ans (<! (pl-answer thread))]
+ (case ans
+ false (if (zero? num-solutions)
+ (put! c "No solutions.")
+ (put! c (str "Found " num-solutions " solutions.")))
+ "nil" (do
+ (put! c {:data (str num-solutions " solutions after " (* (inc cnt) 1000) " tries. Continuing to try...\n")
+ :remove-previous-results true})
+ (<! (timeout 100))
+ (recur (inc cnt) num-solutions))
+ (do
+ (if (< cnt 30)
  (do
- (callback (str (!> js/pl.format_answer ans) "\n"))
- (answer* (inc cnt) (inc num-solutions) callback)))))))
+ (put! c (str (!> js/pl.format_answer ans) "\n"))
+ (<! (timeout 100))
+ (recur (inc cnt) (inc num-solutions)))
+ (put! c (str "Found " num-solutions " so far, they might be more..."))))))))
 
 (defn query [exp _]
- (let [c (chan)]
+ (let [c (chan)
+ Thread (? js/pl.type.Thread) ; to understand the difference between threads and sessions, see https://github.com/jariazavalverde/tau-prolog/issues/64
+ thread (new Thread @session)]
  (try
  (init)
- (let [[status res] (query* exp)]
+ (let [[status res] (query* thread exp)]
  (if (= :error status)
  (put! c res)
- (answer* 0 0 #(put! c %))))
+ (answer* thread c)))
  (catch :default o
  (put! c (str o))))
  c))