Adds dynamo-db.expressions namespace

pom.xml

@@ -11,7 +11,7 @@
 
   <groupId>dehli</groupId>
   <artifactId>serverless</artifactId>
-  <version>0.1.33</version>
+  <version>0.1.34</version>
   <name>serverless</name>
 
   <dependencies>

src/serverless/aws/dynamo_db/expressions.cljs

@@ -0,0 +1,25 @@
+(ns aws.dynamo-db.expressions
+  (:require [clojure.string :refer [join replace]])
+  (:refer-clojure :exclude [replace]))
+
+(defn- escape [v]
+  (-> v str (replace #"-" "") (replace #":" "")))
+
+(defn ->attribute-name-key [v] (str "#" (escape v)))
+(defn ->attribute-value-key [v] (str ":" (escape v)))
+
+(defn ->set-expression [props]
+  (->> (keys props)
+       (map #(str (->attribute-name-key %) " = " (->attribute-value-key %)))
+       (join ", ")
+       (str "set ")))
+
+(defn ->attribute-names [props]
+  (->> (keys props)
+       (map #(vector (->attribute-name-key %) %))
+       (into {})))
+
+(defn ->attribute-values [props]
+  (->> (keys props)
+       (map #(vector (->attribute-value-key %) (get props %)))
+       (into {})))