CODEWITHSUNDEEP
clojurelispjvm-languagesclojure-contrib
Chris
Chris

Reputation: 455

How do I eval a clojure data structure within the context of a namespace?

I'm writing a clojure app for internal use, and I want the config file to be in clojure too. I have defined a few macros to make writing the config file easier, but when I try to eval the data from the config file, it cant find my macros. This works fine from the REPL however. For example, I'm using 

(load-string "/path/to/config")

I get this error:

Exception in thread "main" java.lang.RuntimeException: Unable to resolve symbol: defcmd in this context, compiling:(null:1)
at clojure.lang.Compiler.analyze(Compiler.java:6235)
at clojure.lang.Compiler.analyze(Compiler.java:6177)
at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3452)
at clojure.lang.Compiler.analyzeSeq(Compiler.java:6411)
at clojure.lang.Compiler.analyze(Compiler.java:6216)
at clojure.lang.Compiler.analyze(Compiler.java:6177)
at clojure.lang.Compiler.eval(Compiler.java:6469)
at clojure.lang.Compiler.load(Compiler.java:6902)
at clojure.lang.Compiler.load(Compiler.java:6872)
at clojure.core$load_reader.invoke(core.clj:3625)
at clojure.core$load_string.invoke(core.clj:3635)
at serverStats.core$load_config.invoke(core.clj:67)
at serverStats.core$_main.doInvoke(core.clj:78)
at clojure.lang.RestFn.invoke(RestFn.java:397)
at clojure.lang.Var.invoke(Var.java:397)
at user$eval109.invoke(NO_SOURCE_FILE:1)
at clojure.lang.Compiler.eval(Compiler.java:6465)
at clojure.lang.Compiler.eval(Compiler.java:6455)
at clojure.lang.Compiler.eval(Compiler.java:6431)
at clojure.core$eval.invoke(core.clj:2795)
at clojure.main$eval_opt.invoke(main.clj:296)
at clojure.main$initialize.invoke(main.clj:315)
at clojure.main$null_opt.invoke(main.clj:348)
at clojure.main$main.doInvoke(main.clj:426)
at clojure.lang.RestFn.invoke(RestFn.java:421)
at clojure.lang.Var.invoke(Var.java:405)
at clojure.lang.AFn.applyToHelper(AFn.java:163)
at clojure.lang.Var.applyTo(Var.java:518)
at clojure.main.main(main.java:37)
Caused by: java.lang.RuntimeException: Unable to resolve symbol: defcmd in this context
at clojure.lang.Util.runtimeException(Util.java:156)
at clojure.lang.Compiler.resolveIn(Compiler.java:6720)
at clojure.lang.Compiler.resolve(Compiler.java:6664)
at clojure.lang.Compiler.analyzeSymbol(Compiler.java:6625)
at clojure.lang.Compiler.analyze(Compiler.java:6198)
... 28 more

However, running that same command from the REPL in my namespace works fine.

Upvotes: 3

Views: 1054

Answers (1)

kotarak
kotarak

Reputation: 17299

You probably want some more sophisticated loading scheme. I assume you want to put the configuration into a dedicated configuration namespace. It will only contain the configuration. Helper functions are held in a separate namespace use'd in the configuration namespace. 

(defn setup-config-space
  []
  (binding [*ns* *ns*]
    (in-ns 'config.namespace)
    (refer-clojure)
    (use 'config.helpers)))

(defn load-config
  [path]
  (binding [*ns* *ns*]
    (in-ns 'config.namespace)
    (load-file path)))

See the example use:

..ojure/1.4.0-alpha3% cat config/helpers.clj                             
(ns config.helpers)

(defmacro defcmd
  [x]
  `(defn ~x [] "Hello"))
..ojure/1.4.0-alpha3% cat x.clj
(defcmd foo)
..ojure/1.4.0-alpha3% java -cp .:clojure-1.4.0-alpha3.jar clojure.main -r
Clojure 1.4.0-alpha3
user=> ; Paste above functions
#'user/setup-config-space
#'user/load-config
user=> (setup-config-space)
nil
user=> (load-config "x.clj")
#'config.namespace/foo
user=> (config.namespace/foo)
"Hello"

Upvotes: 5

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