Commas cause all kinds of havoc

[sparkertime]

A comma in the text of an hstore value causes serious problems when reading it out of the DB. Right now pghstore-clj assumes that commas strictly denote the separations between key/value pairs. This goes to hell when there's commas in the text of fields, however.

I suspect a better implementation may be something closer to the state machine approach at http://code.google.com/p/pg-spring-type-mapper/source/browse/src/org/valgog/utils/postgres/HStore.java?spec=svnbac909c06dd97a2c8b2bbfa96141d0e1ba942f73&r=bac909c06dd97a2c8b2bbfa96141d0e1ba942f73

[valpackett]

Temporary hack: replacing ,, = and > with unicode private use characters

(ns hstore
  (:use pghstore-clj.core)
  (:require [clojure.string :as string]))

(defn hstore-escape [v]
  (-> v
      (string/replace "\"" "\\\"")
      (string/replace \, (char 57344))
      (string/replace \= (char 57345))
      (string/replace \> (char 57346))))

(defn hstore-unescape [v]
  (-> v
      (string/replace "\\" "\"")
      (string/replace (char 57344) \,)
      (string/replace (char 57345) \=)
      (string/replace (char 57346) \>)))

(defn from-quoted-hstore [x]
  (into {} (filter identity (map (fn [[k v]] (when v [k (hstore-unescape v)])) (from-hstore x)))))

(defn to-quoted-hstore [x]
  (to-hstore (into {} (map (fn [[k v]] [k (hstore-escape v)]) x))))

Not very good if you need to access the database from other applications as they need to do the same thing…