Clojure

Invalid defrecord results in exception attributed to namespace that imports namespace with defrecord

Details

  • Type: Defect Defect
  • Status: Open Open
  • Priority: Minor Minor
  • Resolution: Unresolved
  • Affects Version/s: Release 1.5
  • Fix Version/s: Release 1.7
  • Component/s: None
  • Patch:
    Code
  • Approval:
    Incomplete

Description

I was introducing a namespace that included a defrecord.

My defrecord was wrong; it used a keyword to define a field, not a symbol. Minimal test case:

% cat src/useclj16/init.clj
(ns useclj16.init)

(defrecord Application [:shutdown-fn])
% cat src/useclj16/app.clj 
(ns useclj16.app
  (:require [useclj16.init :as init]))

However, the exception was perplexing:

% java -cp clojure-1.6.0-master-SNAPSHOT.jar:src clojure.main
user=> (require 'useclj16.app)
ClassCastException clojure.lang.Keyword cannot be cast to clojure.lang.IObj  clojure.core/with-meta (core.clj:214)

user=> (pst *e 100)
ClassCastException clojure.lang.Keyword cannot be cast to clojure.lang.IObj
        clojure.core/with-meta (core.clj:214)
        clojure.core/defrecord/fn--147 (core_deftype.clj:362)
        clojure.core/map/fn--4210 (core.clj:2494)
        clojure.lang.LazySeq.sval (LazySeq.java:42)
        clojure.lang.LazySeq.seq (LazySeq.java:60)
        clojure.lang.RT.seq (RT.java:484)
        clojure.lang.LazilyPersistentVector.create (LazilyPersistentVector.java:31)
        clojure.core/vec (core.clj:354)
        clojure.core/defrecord (core_deftype.clj:362)
        clojure.lang.Var.invoke (Var.java:427)
        clojure.lang.Var.applyTo (Var.java:532)
        clojure.lang.Compiler.macroexpand1 (Compiler.java:6483)
        clojure.lang.Compiler.macroexpand (Compiler.java:6544)
        clojure.lang.Compiler.eval (Compiler.java:6618)
        clojure.lang.Compiler.load (Compiler.java:7079)
        clojure.lang.RT.loadResourceScript (RT.java:370)
        clojure.lang.RT.loadResourceScript (RT.java:361)
        clojure.lang.RT.load (RT.java:440)
        clojure.lang.RT.load (RT.java:411)
        clojure.core/load/fn--5024 (core.clj:5546)
        clojure.core/load (core.clj:5545)
        clojure.core/load-one (core.clj:5352)
        clojure.core/load-lib/fn--4973 (core.clj:5391)
        clojure.core/load-lib (core.clj:5390)
        clojure.core/apply (core.clj:619)
        clojure.core/load-libs (core.clj:5429)
        clojure.core/apply (core.clj:619)
        clojure.core/require (core.clj:5512)
        useclj16.app/eval322/loading--4916--auto----323 (app.clj:1)
        useclj16.app/eval322 (app.clj:1)
        clojure.lang.Compiler.eval (Compiler.java:6634)
        clojure.lang.Compiler.eval (Compiler.java:6623)
        clojure.lang.Compiler.load (Compiler.java:7079)
        clojure.lang.RT.loadResourceScript (RT.java:370)
        clojure.lang.RT.loadResourceScript (RT.java:361)
        clojure.lang.RT.load (RT.java:440)
        clojure.lang.RT.load (RT.java:411)
        clojure.core/load/fn--5024 (core.clj:5546)
        clojure.core/load (core.clj:5545)
        clojure.core/load-one (core.clj:5352)
        clojure.core/load-lib/fn--4973 (core.clj:5391)
        clojure.core/load-lib (core.clj:5390)
        clojure.core/apply (core.clj:619)
        clojure.core/load-libs (core.clj:5429)
        clojure.core/apply (core.clj:619)
        clojure.core/require (core.clj:5512)
        user/eval318 (NO_SOURCE_FILE:1)
        clojure.lang.Compiler.eval (Compiler.java:6634)
        clojure.lang.Compiler.eval (Compiler.java:6597)
        clojure.core/eval (core.clj:2864)
        clojure.main/repl/read-eval-print--6594/fn--6597 (main.clj:260)
        clojure.main/repl/read-eval-print--6594 (main.clj:260)
        clojure.main/repl/fn--6603 (main.clj:278)
        clojure.main/repl (main.clj:278)
        clojure.main/repl-opt (main.clj:344)
        clojure.main/main (main.clj:442)
        clojure.lang.Var.invoke (Var.java:411)
        clojure.lang.Var.applyTo (Var.java:532)
        clojure.main.main (main.java:37)
nil

The error was attributed to app.clj (useclj16.app), a namespace which requires useclj16.init, the namespace containing the defrecord.

No indication that this concerned a defrecord, or even what namespace contained the error, was present in the exception.

Patch: clj-1261-v1.txt

Approach: Check explicitly that the fields are all symbols, for both defrecord and deftype, and throw a CompilerException with file, line, and column number if not. Example of exception after patch is applied, in the case give above:

user=> (require 'useclj16.app)
CompilerException java.lang.AssertionError: defrecord and deftype fields must be symbols.  These are not allowed: (:shutdown-fn), compiling:(useclj16/init.clj:3:1)

Activity

Hide
Alex Miller added a comment -

I think the patch is ok but I have two suggestions in the error message - first, include the record/type ns+name (I think the classname in the patched fn is what you want). Second, I think the wording could be adjusted a bit and the parens should go away - those look like but don't actually have meaning in the original context (since you are filtering out the symbols). Maybe something like:

"defrecord and deftype fields must be symbols, useclj16.init.Application had: :shutdown-fn, :foo-bar"

Show
Alex Miller added a comment - I think the patch is ok but I have two suggestions in the error message - first, include the record/type ns+name (I think the classname in the patched fn is what you want). Second, I think the wording could be adjusted a bit and the parens should go away - those look like but don't actually have meaning in the original context (since you are filtering out the symbols). Maybe something like: "defrecord and deftype fields must be symbols, useclj16.init.Application had: :shutdown-fn, :foo-bar"
Hide
Andy Fingerhut added a comment -

Patch clj-1261-2.diff is identical to clj-1261-v1.txt except that it applies cleanly to latest master. The only change was to some lines of context due to recent commits to Clojure.

Show
Andy Fingerhut added a comment - Patch clj-1261-2.diff is identical to clj-1261-v1.txt except that it applies cleanly to latest master. The only change was to some lines of context due to recent commits to Clojure.
Hide
Andy Fingerhut added a comment -

Updated description to give minimal test case.

Show
Andy Fingerhut added a comment - Updated description to give minimal test case.
Hide
Andy Fingerhut added a comment -

Patch clj-1261-v1.txt throws an exception if any fields given to defrecord or deftype are not symbols. They are CompilerExceptions, so include an accurate file, line, and column number.

Show
Andy Fingerhut added a comment - Patch clj-1261-v1.txt throws an exception if any fields given to defrecord or deftype are not symbols. They are CompilerExceptions, so include an accurate file, line, and column number.
Hide
Howard Lewis Ship added a comment -

"Feedback" is my own personal crusade http://tapestryjava.blogspot.com/2013/05/once-more-feedback-please.html

In my case, my invalid code was:

(defrecord Application [:shutdown-fn])

And the mistake was that :shutdown-fn should be a symbol, not a keyword.

Here it is, more completely:

(ns novate.services.initialization
  "Infrastructure for system-as-transient state.")

(defrecord Application [:shutdown-fn])

and

(ns novate.services.activator
  "Responsible for bootstrapping the application by loading certain namespaces and invoking certain functions, guided by data in JAR manifests."
  (:gen-class)
  (:require [clojure.edn :as edn]
            [clojure.java.io :as io]
            [novate.util.logging :as l]
            [novate.services
             [initialization :as init]
             [ordering :as o]])
  (:import [java.io PushbackReader]))

The error was attributed to this file.

Show
Howard Lewis Ship added a comment - "Feedback" is my own personal crusade http://tapestryjava.blogspot.com/2013/05/once-more-feedback-please.html In my case, my invalid code was:
(defrecord Application [:shutdown-fn])
And the mistake was that :shutdown-fn should be a symbol, not a keyword. Here it is, more completely:
(ns novate.services.initialization
  "Infrastructure for system-as-transient state.")

(defrecord Application [:shutdown-fn])
and
(ns novate.services.activator
  "Responsible for bootstrapping the application by loading certain namespaces and invoking certain functions, guided by data in JAR manifests."
  (:gen-class)
  (:require [clojure.edn :as edn]
            [clojure.java.io :as io]
            [novate.util.logging :as l]
            [novate.services
             [initialization :as init]
             [ordering :as o]])
  (:import [java.io PushbackReader]))
The error was attributed to this file.
Hide
Alex Miller added a comment -

Also, "feedback" is not a useful label. Please use "errormsgs" for stuff like this. See the list of many commonly used labels here: http://dev.clojure.org/display/community/Creating+Tickets

Show
Alex Miller added a comment - Also, "feedback" is not a useful label. Please use "errormsgs" for stuff like this. See the list of many commonly used labels here: http://dev.clojure.org/display/community/Creating+Tickets
Hide
Alex Miller added a comment -

Can you include an example of the defrecord definition just so we're clear what it looks like?

Show
Alex Miller added a comment - Can you include an example of the defrecord definition just so we're clear what it looks like?

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Dates

  • Created:
    Updated: