add general using-* index support

Signed-off-by: Sean Corfield <sean@corfield.org>

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changes
 
 * 2.7.next in progress
+  * Support `USING HASH` as well as `USING GIN`.
   * Fix [#571](https://github.com/seancorfield/honeysql/issues/571) by allowing `:order-by` to take an empty sequence of columns (and be omitted).
   * Update dev/build deps.
 

doc/clause-reference.md

@@ -149,6 +149,14 @@ user=> (sql/format {:create-index [:my-idx [:fruit :using-gin :appearance]]})
 ["CREATE INDEX my_idx ON fruit USING GIN (appearance)"]
 ```
 
+As of 2.7.next, `USING HASH` index creation is also possible using the keyword
+`:using-hash` after the table name (or the symbol `using-hash`):
+
+```clojure
+user=> (sql/format {:create-index [:my-idx [:fruit :using-hash :appearance]]})
+["CREATE INDEX my_idx ON fruit USING HASH (appearance)"]
+```
+
 ### rename-table
 
 Used with `:alter-table`,

src/honey/sql.cljc

@@ -370,6 +370,20 @@
       (keyword (name s)))
     s))
 
+(defn- kw->sym
+  "Given a keyword, produce a symbol, retaining the namespace
+  qualifier, if any."
+  [k]
+  (if (keyword? k)
+    #?(:bb (if-let [n (namespace k)]
+             (symbol n (name k))
+             (symbol (name k)))
+       :clj (.sym ^clojure.lang.Keyword k)
+       :default (if-let [n (namespace k)]
+                  (symbol n (name k))
+                  (symbol (name k))))
+    k))
+
 (defn- inline-map [x & [open close]]
   (str (or open "{")
        (join ", " (map (fn [[k v]]
@@ -1418,10 +1432,12 @@
 (defn- format-create-index [k clauses]
   (let [[index-spec [table & exprs]] clauses
         [pre entity ine & more] (destructure-ddl-item index-spec (str (sql-kw k) " options"))
-        [using & exprs] (if (contains? #{:using-gin 'using-gin}
+        [using & exprs]
-                                       (first exprs))
+        (let [item (first exprs)]
+          (if (and (ident? item)
+                   (str/starts-with? (str (kw->sym item)) "using-"))
             exprs
-                          (cons nil exprs))
+            (cons nil exprs)))
         [sqls params] (format-expr-list exprs)]
     (into [(join " " (remove empty?)
                  (-> ["CREATE" pre "INDEX" ine entity
@@ -1732,20 +1748,6 @@
            (set @current-clause-order)
            (set (keys @clause-format))))
 
-(defn- kw->sym
-  "Given a keyword, produce a symbol, retaining the namespace
-  qualifier, if any."
-  [k]
-  (if (keyword? k)
-    #?(:bb (if-let [n (namespace k)]
-             (symbol n (name k))
-             (symbol (name k)))
-       :clj (.sym ^clojure.lang.Keyword k)
-       :default (if-let [n (namespace k)]
-                  (symbol n (name k))
-                  (symbol (name k))))
-    k))
-
 (defn format-dsl
   "Given a hash map representing a SQL statement and a hash map
   of options, return a vector containing a string -- the formatted

test/honey/sql/helpers_test.cljc

@@ -1038,11 +1038,15 @@
            (sql/format (create-index [:unique :my-column-idx :if-not-exists] [:my-table :my-column]))))
     (is (= ["CREATE INDEX my_column_idx ON my_table (LOWER(my_column))"]
            (sql/format (create-index :my-column-idx [:my-table :%lower.my-column])))))
-  (testing "PostgreSQL extensions (USING GIN)"
+  (testing "PostgreSQL extensions (USING GIN/HASH)"
     (is (= ["CREATE INDEX my_column_idx ON my_table USING GIN (my_column)"]
            (sql/format {:create-index [:my-column-idx [:my-table :using-gin :my-column]]})))
     (is (= ["CREATE INDEX my_column_idx ON my_table USING GIN (my_column)"]
-           (sql/format (create-index :my-column-idx [:my-table :using-gin :my-column]))))))
+           (sql/format (create-index :my-column-idx [:my-table :using-gin :my-column]))))
+    (is (= ["CREATE INDEX my_column_idx ON my_table USING HASH (my_column)"]
+           (sql/format {:create-index [:my-column-idx [:my-table :using-hash :my-column]]})))
+    (is (= ["CREATE INDEX my_column_idx ON my_table USING HASH (my_column)"]
+           (sql/format (create-index :my-column-idx [:my-table :using-hash :my-column]))))))
 
 (deftest join-with-alias
   (is (= ["SELECT * FROM foo LEFT JOIN (populatons AS pm INNER JOIN customers AS pc ON (pm.id = pc.id) AND (pm.other_id = pc.other_id)) ON foo.fk_id = pm.id"]