Handle special case of cardinality [0..0] and wildcard values

When handling refinements, we can transform wildcard values to a count of attributes query, such that a search is performed for results with >0 attributes matching the query. However, when used in conjunction with a [0..0] cardinality, we must reverse this wildcard filter so that we actually exclude results with >0 attributes. When the expression contains a minimum cardinality of zero, we are careful to avoid adding an attribute count query, and for each value, simply exclude results with an attribute count greater than the maximum requested. Fixes #46.

src/com/eldrix/hermes/impl/ecl.clj

@@ -461,9 +461,10 @@
       (search/q-or (map #(search/q-attribute-in-set % (realise-concept-ids ctx incl)) attribute-concept-ids)))))
 
 (defn- parse-attribute--expression
-  [ctx cardinality reverse-flag? attribute-concept-ids loc]
+  [ctx {min-value :min-value max-value :max-value :as cardinality} reverse-flag? attribute-concept-ids loc]
   (let [sub-expression (zx/xml1-> loc :subExpressionConstraint (partial parse-subexpression-constraint ctx))
-        attribute-query (make-attribute-query ctx sub-expression attribute-concept-ids)]
+        attribute-query (when-not (and cardinality (zero? min-value)) (make-attribute-query ctx sub-expression attribute-concept-ids))
+        cardinality-queries (when cardinality (seq (remove nil? (map #(search/q-attribute-count % min-value max-value) attribute-concept-ids))))]
     (cond
       ;; we are not trying to implement edge case of an expression containing both cardinality and reversal, at least not yet
       ;; see https://confluence.ihtsdotools.org/display/DOCECL/6.3+Cardinality for how it *should* work
@@ -476,10 +477,11 @@
       (process-dotted ctx (realise-concept-ids ctx sub-expression) [(search/q-concept-ids attribute-concept-ids)])
 
       ;; if we have cardinality, add a clause to ensure we have the right count for those properties
-      cardinality
-      (search/q-and (filter identity
-                            (conj (map #(search/q-attribute-count % (:min-value cardinality) (:max-value cardinality)) attribute-concept-ids)
-                                  attribute-query)))
+      (and attribute-query cardinality-queries)
+      (search/q-and (conj cardinality-queries attribute-query))
+
+      cardinality-queries
+      cardinality-queries
 
       :else
       attribute-query)))

src/com/eldrix/hermes/impl/search.clj

@@ -556,7 +556,7 @@ items."
       (q-not (MatchAllDocsQuery.) (IntPoint/newRangeQuery field 1 Integer/MAX_VALUE))
 
       (and (zero? minimum) (pos? maximum))
-      (q-not (MatchAllDocsQuery.) (IntPoint/newRangeQuery field 1 (int maximum))))))
+      (q-not (MatchAllDocsQuery.) (IntPoint/newRangeQuery field (int (inc maximum)) Integer/MAX_VALUE)))))
 
 (defn q-term [s] (make-tokens-query s))
 

test/com/eldrix/hermes/ecl_test.clj

@@ -2,7 +2,7 @@
   (:require [clojure.core.async :as a]
             [clojure.set :as set]
             [clojure.spec.test.alpha :as stest]
-            [clojure.test :refer [deftest is use-fixtures run-tests]]
+            [clojure.test :refer [deftest is use-fixtures run-tests testing]]
             [com.eldrix.hermes.core :as hermes]
             [com.eldrix.hermes.impl.store :as store]
             [com.eldrix.hermes.rf2]
@@ -164,6 +164,16 @@
         (is (seq results) "Invalid results")
         (is (every? true? results) "Invalid results")))))
 
+(deftest ^:live test-cardinality
+  (testing "Cardinality 0..1 and 1..1"
+    (let [r0-1 (hermes/expand-ecl *svc* "<<24700007: [0..1] 370135005=*")  ;;370135005 = pathological process
+          r1-1 (hermes/expand-ecl *svc* "<<24700007: [1..1] 370135005=*")]
+      (is (seq r1-1) "Multiple sclerosis and descendants should have attribute of 'pathological process'")
+      (is (>= (count r0-1) (count r1-1)) "Results for cardinality 0..1 should be the same, more than 1..1")
+      (is (set/subset? (set r1-1) (set r0-1)) "Results for cardinality 1..1 should a subset of 0..1")))
+  (testing "Zero cardinality"
+    (let [results (hermes/expand-ecl *svc* "<<24700007: [0..0] 246075003=*")] ;; 246075003 = causative agent.
+      (is (seq results) "Invalid result. Multiple sclerosis and descendants should not have attributes of 'causative agent'"))))
 
 (comment
   (def ^:dynamic *svc* (hermes/open "snomed.db"))