@@ -10,6 +10,8 @@

   [day8.re-frame/tracing "0.6.2"]

   [garden "1.3.10"]

   [net.dhleong/spade "1.1.0"]

+  [org.babashka/sci "0.5.34"]

+  [org.clojure/core.match "1.0.0"]

   [day8/shadow-git-inject "0.0.5"]

   [binaryage/devtools "1.0.3"]

@@ -1,8 +1,11 @@

 (ns dmr.events

   (:require

-   [cljs.reader :refer [read-string]]

-   [clojure.string :refer [lower-case split join starts-with?]]

+   [clojure.edn :as edn]

+   [clojure.core.match :refer-macros [match]]

+   [clojure.walk :refer [postwalk]]

+   [clojure.string :refer [lower-case split join starts-with? replace]]

    [re-frame.core :as re-frame]

+   [sci.core :as sci]

    [dmr.db :as db]

    [day8.re-frame.tracing :refer-macros [fn-traced]]))

@@ -77,6 +80,30 @@

                            (roll-dice (edn/read-string ndice) (edn/read-string nsides))))]

     (replace s dice-regex evaluated-roll)))

+(defn infixify [expr]

+  (match [expr]

+    [([x] :seq)] (infixify x)

+    [([x op & rest] :seq)] (list op (infixify x) (infixify rest))

+    [x :guard number?] x

+    :else (throw (js/Error. (str "Expected number, but got '" (pr-str expr) "'")))))

+

+

+(defn evaluate-roll-expression [s]

+  (let [string-expr (evaluate-rolls s)

+        result (as-> string-expr x

+                 (str "(" x ")")  ;So that 'read-string' reads everything

+                 (edn/read-string x)

+                 (postwalk #(if (vector? %) (reduce + %) %) x)

+                 (infixify x)

+                 (pr-str x)

+                 (sci/eval-string x))]

+     {:roll-expression string-expr :result result}))

+

+(defn safely-evaluate-roll-expression [s]

+  (try

+    (evaluate-roll-expression s)

+    (catch js/Error e {:err (.-message e)})))

+

 (defn execute [db cmdline]

  (let [append-history #(update-in db [:cmdline :history] conj {:input cmdline :output %})

        entities (db :entities)