Release 7.046

Author: cnuernber

CHANGELOG.md

@@ -1,4 +1,7 @@
 # Changelog
+# 7.046
+ * dataset parsers return something that is not a dataset when the internal datasets have no columns.
+ 
 # 7.045
  * Bulk add-constant! method used for adding missing values.
 

deps.edn

@@ -14,7 +14,7 @@
    :exec-fn codox.main/-main
    :exec-args {:group-id "techascent"
                :artifact-id "tech.ml.dataset"
-               :version "7.045"
+               :version "7.046"
                :name "TMD"
                :description "A Clojure high performance data processing system"
                :metadata {:doc/format :markdown}

docs/000-getting-started.html

@@ -62,7 +62,10 @@
               init (hamf/range (.value row-idx)))))
   IDeref
   (deref [this]
-    (parse-context/parsers->dataset (assoc options :key-fn nil) parsers (.value row-idx)))
+    (if (.isEmpty ^Map parsers)
+      {:tech.v3.dataset/row-count (.value row-idx)
+       :tech.v3.dataset/missing :all}
+      (parse-context/parsers->dataset (assoc options :key-fn nil) parsers (.value row-idx))))
   PClearable
   (ds-clear [this]
     (reduce (fn [_ p] (ds-proto/ds-clear p)) nil (.values ^Map parsers))

docs/100-walkthrough.html

@@ -0,0 +1,13 @@
+(ns tech.v3.dataset.parser-test
+  (:require [tech.v3.dataset :as ds]
+            [tech.v3.dataset.protocols :as ds-proto]
+            [clojure.test :refer [deftest is]]))
+
+
+(deftest all-missing-ds
+  (let [p (ds/dataset-parser)
+        _ (ds-proto/add-row p {})
+        ds @p]
+    (is (not (ds/dataset? ds)))
+    (is (= 1 (:tech.v3.dataset/row-count ds))
+        (= :all (:tech.v3.dataset/missing ds)))))