Merge pull request #88 from scicloj/fix-79-add-restart

Fix #79 Add core/restart

src/wolframite/base/convert.clj

@@ -115,9 +115,13 @@
         ;(let [s (str-utils/replace (str sym) #"\|(.*?)\|" #(str "\\\\[" (second %) "]"))]   )
         (let [s (str sym)]
           (if (re-find #"[^a-zA-Z0-9$\/]" s)
-            (throw (Exception. (str "Symbols passed to Mathematica must be alphanumeric (apart from forward slashes and dollar signs). Passed: "
-                                    s
-                                    "Known aliases:" (keys aliases))))
+            (throw (ex-info (str "Unsupported symbol / unknown alias: Symbols passed to Mathematica must be alphanumeric"
+                                 " (apart from forward slashes and dollar signs). Other symbols may"
+                                 " only be used if there is defined a Wolframite alias for them."
+                                 " Passed: " s
+                                 " Known aliases: " (or (-> aliases keys sort seq) "N/A"))
+                            {:unknown-symbol s
+                             :known-symbols (keys aliases)}))
             (proto/expr (jlink-instance/get) :Expr/SYMBOL s)))))))
 
 (defn- convert-non-simple-list [elms opts]

src/wolframite/core.clj

@@ -86,13 +86,6 @@
    (->> (kernel-link-opts init-opts)
         (proto/create-kernel-link jlink-impl))))
 
-(defn stop
-  "Sends a request to the kernel to shut down.
-
-  See https://reference.wolfram.com/language/JLink/ref/java/com/wolfram/jlink/KernelLink.html#terminateKernel()"
-  []
-  (proto/terminate-kernel! (jlink-instance/get)))
-
 (defn- unqualify [form]
   (walk/postwalk (fn [form]
                    (if (qualified-symbol? form)
@@ -166,6 +159,20 @@
      nil)
    nil))
 
+(defn stop
+  "Sends a request to the kernel to shut down.
+
+  See https://reference.wolfram.com/language/JLink/ref/java/com/wolfram/jlink/KernelLink.html#terminateKernel()"
+  []
+  (some-> (jlink-instance/get) (proto/terminate-kernel!))
+  (jlink-instance/reset!)
+  (reset! kernel-link-atom nil))
+
+(defn restart
+  "Same as calling [[stop]] then [[start]]"
+  ([] (stop) (start))
+  ([opts] (stop) (start opts)))
+
 (defn eval
   "Evaluate the given Wolfram expression (a string, or a Clojure data) and return the result as Clojure data.
 

src/wolframite/impl/jlink_instance.clj

@@ -1,9 +1,11 @@
 (ns wolframite.impl.jlink-instance
   (:require [wolframite.impl.protocols :as proto])
   (:import [wolframite.impl.protocols JLink])
-  (:refer-clojure :exclude [get]))
+  (:refer-clojure :exclude [get reset!]))
 
 ;; The actual impl. of the JLink interface, set at runtime
 (defonce jlink-instance (atom nil))
 
 (defn ^JLink get [] (deref jlink-instance))
+
+(defn reset! [] (clojure.core/reset! jlink-instance nil))

src/wolframite/impl/jlink_proto_impl.clj

@@ -57,30 +57,43 @@
 (defrecord JLinkImpl [opts kernel-link-atom]
   proto/JLink
   (create-kernel-link [_this kernel-link-opts]
-    (try (let [opts-array (into-array String kernel-link-opts)
-               kernel-link
-               (->> (doto (MathLinkFactory/createKernelLink ^"[Ljava.lang.String;" opts-array)
-                      (.discardAnswer))
-                    (reset! kernel-link-atom))]
-           ;(.getError kernel-link) (.getErrorMessage kernel-link)
-           kernel-link)
-         (catch MathLinkException e
-           (if (= (ex-message e) "MathLink connection was lost.")
-             (throw (ex-info (str "MathLink connection was lost. Perhaps you need to activate Mathematica first,"
-                                  " you are trying to start multiple concurrent connections (from separate REPLs),"
-                                  " or there is some other issue and you need to retry, or restart and retry...")
-                             {:kernel-link-opts (cond-> kernel-link-opts
-                                                        (array? kernel-link-opts)
-                                                        vec)
-                              :cause e}))
-             (throw e)))
-         (catch Exception e
-           (throw (ex-info (str "Failed to start a Math/Wolfram Kernel process: "
-                                (ex-message e)
-                                " Verify the settings are correct: `" kernel-link-opts "`")
-                           {:kernel-opts kernel-link-opts})))))
+    (loop [attempts 3, wait-ms 10, orig-err nil]
+      ;; Sometimes, starting a link may fail b/c the previous one
+      ;; has not been shut down properly
+      (let [res
+            (try (let [opts-array (into-array String kernel-link-opts)
+                       kernel-link
+                       (->> (doto (MathLinkFactory/createKernelLink ^"[Ljava.lang.String;" opts-array)
+                              (.discardAnswer))
+                            (reset! kernel-link-atom))]
+                   ;(.getError kernel-link) (.getErrorMessage kernel-link)
+                   kernel-link)
+                 (catch MathLinkException e
+                   (if (= (ex-message e) "MathLink connection was lost.")
+                     (throw (ex-info (str "MathLink connection was lost. Perhaps you need to activate Mathematica first,"
+                                          " you are trying to start multiple concurrent connections (from separate REPLs),"
+                                          " or there is some other issue and you need to retry, or restart and retry...")
+                                     {:kernel-link-opts (cond-> kernel-link-opts
+                                                                (array? kernel-link-opts)
+                                                                vec)
+                                      :cause e}))
+                     (throw e)))
+                 (catch Exception e
+                   (throw (ex-info (str "Failed to start a Math/Wolfram Kernel process: "
+                                        (ex-message e)
+                                        " Verify the settings are correct: `" kernel-link-opts "`")
+                                   {:kernel-opts kernel-link-opts}))))]
+        (if (instance? Exception res)
+          (if (pos? attempts)
+            (do (Thread/sleep wait-ms)
+                (recur (dec attempts) (* 3 wait-ms) (or orig-err res)))
+            (throw orig-err))
+          res))))
   (terminate-kernel! [_this]
-    (.terminateKernel ^KernelLink @kernel-link-atom)
+    ;; BEWARE: it is not absolutely guaranteed that the kernel will die immediately
+    (doto ^KernelLink @kernel-link-atom
+      (.terminateKernel)
+      (.close))
     (reset! kernel-link-atom nil))
   (expr [_this primitive-or-exprs]
     (make-expr primitive-or-exprs))

test/wolframite/core_test.clj

@@ -2,7 +2,8 @@
   (:require [clojure.test :refer [deftest testing is]]
             [wolframite.core :as wl]
             [wolframite.impl.wolfram-syms.wolfram-syms :as wolfram-syms]
-            [wolframite.wolfram :as w]))
+            [wolframite.wolfram :as w])
+  (:import (clojure.lang ExceptionInfo)))
 
 ;; * Basic Sanity Checks
 
@@ -43,6 +44,22 @@
          (eval '(-> #'w2/Plus meta :doc)))
       "Interned vars have docstrings"))
 
+(deftest restart
+  (testing "first set of aliases"
+    (wl/restart {:aliases '{** Power}})
+    (is (= 8
+           (wl/eval '(** 2 3)))
+        "** is an alias for Power (and 2^3 is 8)"))
+  (testing "restart & another aliases"
+    (wl/restart {:aliases '{pow Power}})
+    (is (thrown-with-msg? ExceptionInfo
+                          #"Unsupported symbol / unknown alias"
+                          (wl/eval '(** 2 3)))
+        "** is not known anymore")
+    (is (= 8
+           (wl/eval '(pow 2 3)))
+        "Now, `pow` is an alias for Power (and 2^3 is 8)")))
+
 (deftest bug-fixes
   (wl/start)
   (testing "#76 double eval of ->"