Allow to specify an eval mode via ':nextjournal.clerk/eval' setting

with values :skip, :sci, :jvm (default)

src/nextjournal/clerk/eval.clj

@@ -229,10 +229,14 @@
         {:as evaluated-doc :keys [blob-ids]}
         (reduce (fn [state cell]
                   (when (and (parser/code? cell) set-status-fn)
-                    (set-status-fn (->eval-status analyzed-doc (count (filter parser/code? (:blocks state))) cell)))
+                    (set-status-fn (->eval-status analyzed-doc (count (filter parser/eval? (:blocks state))) cell)))
                   (let [state-with-deref-deps-evaluated (analyzer/hash-deref-deps state cell)
-                        {:as result :nextjournal/keys [blob-id]} (when (parser/code? cell)
-                                                                   (read+eval-cached state-with-deref-deps-evaluated cell))]
+                        {:as result :nextjournal/keys [blob-id]}
+                        (cond
+                          (parser/eval? cell)
+                          (read+eval-cached state-with-deref-deps-evaluated cell)
+                          (parser/sci-eval? cell)
+                          {:nextjournal/value (v/->viewer-eval (:form cell))})]
                     (cond-> (update state-with-deref-deps-evaluated :blocks conj (cond-> cell result (assoc :result result)))
                       blob-id (update :blob-ids conj blob-id)
                       blob-id (assoc-in [:blob->result blob-id] result))))

src/nextjournal/clerk/parser.cljc

@@ -52,6 +52,7 @@
   #{:nextjournal.clerk/auto-expand-results?
     :nextjournal.clerk/budget
     :nextjournal.clerk/css-class
+    :nextjournal.clerk/eval
     :nextjournal.clerk/render-opts
     :nextjournal.clerk/page-size
     :nextjournal.clerk/render-evaluator
@@ -200,6 +201,14 @@
 (defn code? [{:as block :keys [type]}]
   (contains? #{:code} type))
 
+(def eval?
+  (every-pred code?
+              (complement (comp #{:sci :skip} :nextjournal.clerk/eval :settings))))
+
+(def sci-eval?
+  (every-pred code?
+              (comp #{:sci} :nextjournal.clerk/eval :settings)))
+
 (defn merge-settings [current-settings new-settings]
   (-> (merge-with merge current-settings (select-keys new-settings [:nextjournal.clerk/visibility]))
       (merge (dissoc new-settings :nextjournal.clerk/visibility))))

src/nextjournal/clerk/viewer.cljc

@@ -126,11 +126,18 @@
 #_(ensure-wrapped 123)
 #_(ensure-wrapped {:nextjournal/value 456})
 
+(defn get-safe
+  ([key] #(get-safe % key))
+  ([map key]
+   (when (map? map)
+     (try (get map key) ;; can throw for e.g. sorted-map
+          (catch #?(:clj Exception :cljs js/Error) _e nil)))))
+
 (defn ->value
   "Takes `x` and returns the `:nextjournal/value` from it, or otherwise `x` unmodified."
   [x]
   (if (wrapped-value? x)
-    (:nextjournal/value x)
+    (get-safe x :nextjournal/value)
     x))
 
 #_(->value (with-viewer `code-viewer '(+ 1 2 3)))
@@ -241,13 +248,6 @@
 
 #_(->> "x^2" (with-viewer `latex-viewer) (with-viewers [{:name `latex-viewer :render-fn `mathjax-viewer}]))
 
-(defn get-safe
-  ([key] #(get-safe % key))
-  ([map key]
-   (when (map? map)
-     (try (get map key) ;; can throw for e.g. sorted-map
-          (catch #?(:clj Exception :cljs js/Error) _e nil)))))
-
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; table viewer normalization
 
@@ -563,7 +563,7 @@
     {:code? (not= :hide code)
      :result? (and (:result cell)
                    (or (not= :hide result)
-                       (-> cell :result :nextjournal/value (get-safe :nextjournal/value) viewer-eval?)))}))
+                       (-> cell :result ->value ->value viewer-eval?)))}))
 
 (defn hidden-viewer-eval-result? [{:keys [settings result]}]
   (and (= :hide (-> settings :nextjournal.clerk/visibility :result))