Add wildcard search

README.md

@@ -127,6 +127,43 @@ returns the same anagrams:
 ]
 ```
 
+### Wildcards
+
+Find the single words from the given wildcard (use `?` or `.` for a single
+character or `*` for a sequence) - at the REPL:
+
+```clojure
+(use 'ars-magna.dict)
+(use 'ars-magna.solver)
+
+(->
+  (load-word-list :en-GB)
+  (wildcard "c..p..e")
+  sort)
+; ("compare" "compete" "compile"
+;  "compose" "compote" "compute"
+;  "coppice" "cowpoke" "cripple"
+
+or querying the web service for the word 'compute':
+
+    $ curl -s http://localhost:3000/wildcard/c..p..e | jq .
+
+returns the same words:
+
+```json
+[
+  "compare",
+  "compete",
+  "compile",
+  "compose",
+  "compote",
+  "compute",
+  "coppice",
+  "cowpoke",
+  "cripple"
+]
+
+
 ## References
 
 * https://en.wikipedia.org/wiki/Letter_frequency#Relative_frequencies_of_letters_in_the_English_language

src/ars_magna/handler.clj

@@ -49,7 +49,15 @@
                (longest
                 (get-in (make-indexes :en-GB) [:index :sorted-letter])
                 (clean word)
-                (min-size req 4)))))))
+                (min-size req 4))))))
+
+  (GET "/wildcard/:word" [word :as req]
+    (json-exception-handler
+     (to-json identity
+              (sort
+               (wildcard
+                (get-in (make-indexes :en-GB) [:dict])
+                word))))))
 
 (def app
   (->

src/ars_magna/solver.clj

@@ -24,3 +24,18 @@
    (range min-size (inc (count word)))
    (mapcat #(map sort (c/combinations word %)))
    (mapcat index)))
+
+(defn- case-insensitive [re] (str "(?i)" re))
+
+(defn- assemble-regex [word]
+  (->
+   word
+   (s/replace "?" ".")
+   (s/replace "*" ".+")
+   case-insensitive
+   re-pattern))
+
+(defn wildcard [dict word]
+  (println word)
+  (println (assemble-regex word))
+  (filter (partial re-matches (assemble-regex word)) dict))