[#CLJ-1159] clojure.java.io/delete-file doesn't return the status of the deletion(true/false) - Clojure JIRA

Details

Type: Defect
Status: Open
Priority: Minor
Resolution: Unresolved
Affects Version/s: Release 1.5
Fix Version/s: None
Component/s: None
Labels:
- delete-file
- evil
- or
Environment:
any

Description

initially reported it here(somehow):
https://groups.google.com/d/msg/clojure/T9Kvr0IL0kg/wcKBfR9w_1sJ

Basically clojure.java.io/delete-file doesn't ever return false (even when silently is true, it returns the value of silently), it's due to how it's implemented - but it's obvious from the code, so I'll stop here.

Thanks.

PS: this is what I'm using as my current workaround:
(defn delete-file
"
an implementation that returns the true/false status
which clojure.java.io/delete-file doesn't do(tested in 1.5.0-RC14)
"
[f & [silently]]
(let [ret (.delete (clojure.java.io/file f))]
(cond (or ret silently)
ret
:else
(throw (java.io.IOException. (str "Couldn't delete " f)))
)
)
)

I'm sure you guys can find a better way, but as a clojure newbie(really!) that's what I have.

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AtKaaZ added a comment - 10/Feb/13 2:01 PM

I kinda just realized it affects all versions since and including 1.2, because it appears that its implementation was the same since then.

If it's not meant to return the result of the delete, maybe it should specifically return nil and/or the doc say something?

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AtKaaZ added a comment - 10/Feb/13 2:01 PM I kinda just realized it affects all versions since and including 1.2, because it appears that its implementation was the same since then. If it's not meant to return the result of the delete, maybe it should specifically return nil and/or the doc say something?

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Sean Corfield added a comment - 10/Feb/13 2:21 PM

As noted in a thread on the Clojure ML, you can pass a known value in the second argument position to detect a delete that failed:

(clojure.java.io/delete-file some-file :not-deleted)

This returns true on success and :not-deleted on failure.

However the docstring could be better worded to make that intention clear. Perhaps:

Delete file f. Return true if it succeeds. If silently is nil or false, raise an exception if it fails, else return the value of silently.
This allows you to detect whether the delete succeeded without catching an exception by passing a non-true truthy value as the second argument.

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Sean Corfield added a comment - 10/Feb/13 2:21 PM As noted in a thread on the Clojure ML, you can pass a known value in the second argument position to detect a delete that failed: (clojure.java.io/delete-file some-file :not-deleted) This returns true on success and :not-deleted on failure. However the docstring could be better worded to make that intention clear. Perhaps: Delete file f. Return true if it succeeds. If silently is nil or false, raise an exception if it fails, else return the value of silently. This allows you to detect whether the delete succeeded without catching an exception by passing a non-true truthy value as the second argument.

People

Assignee:

Unassigned

Reporter:

AtKaaZ

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Dates

Created:

10/Feb/13 1:55 PM

Updated:

10/Feb/13 2:21 PM