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[TNS-1] Workaround to Clojure 1.2 reader bug Created: 14/Dec/11  Updated: 10/Jan/14  Resolved: 24/Apr/12

Status: Closed
Project: tools.namespace
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Major
Reporter: Sam Ritchie Assignee: Stuart Sierra
Resolution: Completed Votes: 2
Labels: None

Mac OS X, Clojure 1.2.1, Leiningen 1.6.2

Attachments: Text File 0001-Workaround-to-Clojure-1.2-reader-bug.patch    
Patch: Code and Test


The clojure 1.2 reader will allow invalid forms like {:key} to be read in, and only throw an exception on printing. Currently clojure.tools.namespace calls (read rdr) within a try form; the bug means that this particular type of error is never caught. This patch forces the reader to try and resolve with str, allowing clojure.tools.namespace to catch and bury the error.

I was running into this with moustache templates from lein-newnew on the classpath; these contain namespace headers that look like (ns name.core). This would cause (clojure.tools.namespace/find-namespaces-on-classpath) to fail when printing its results but not when actually running.

Comment by Sam Ritchie [ 14/Dec/11 4:55 PM ]

Funny, jira picked up the moustache markup. a bad namespace looks like (ns { { name } } . core).

Comment by Sam Ritchie [ 11/Jan/12 3:59 PM ]

Ping – Stuart, any thoughts on this?

Comment by Stuart Sierra [ 11/Jan/12 6:09 PM ]

Why should tools.ns do this? If the syntax is wrong, it's wrong.

Comment by Sam Ritchie [ 11/Jan/12 6:43 PM ]

Because without this patch, it's impossible to catch and bury errors from invalid reader syntax. I believe this comes from a bug in the reader that was fixed with 1.2.

Comment by Stuart Sierra [ 27/Jan/12 9:44 AM ]

Declined. It is not the responsibility of this library to catch errors in old versions of Clojure.

Comment by Stuart Sierra [ 24/Apr/12 2:01 PM ]

Reopening because this is still a visible issue for some libraries. I still don't like it, but I'm going to include it.

Comment by Stuart Sierra [ 24/Apr/12 2:04 PM ]

Patch applied.

Comment by Sam Ritchie [ 24/Apr/12 2:07 PM ]

Great, thanks!

Comment by Stuart Sierra [ 10/Jan/14 11:26 AM ]

Mark old resolved issues as 'closed'

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