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[CLJS-817] Warning on use of undeclared var when creating recursive definition Created: 17/Jun/14  Updated: 01/Jul/14  Resolved: 01/Jul/14

Status: Closed
Project: ClojureScript
Component/s: None
Affects Version/s: None
Fix Version/s: None

Type: Defect Priority: Trivial
Reporter: Mike Fikes Assignee: Unassigned
Resolution: Completed Votes: 0
Labels: None

Attachments: Text File cljs_817.patch    

 Description   

If you create a definition that recursively refers to itself, a warning is issued. This is simply a warning; the generated code still works. The same code works without such a warning in Clojure.

Here is an example:

(ns foo.bar)

(def fib-seq (lazy-cat [0 1] (map + (rest fib-seq) fib-seq)))

This generates the following warning:

Compiling "js/main.js" from ["src/cljs" "src/clj"]...
WARNING: Use of undeclared Var foo.bar/fib-seq at line 3 src/cljs/foo/bar.cljs
WARNING: Use of undeclared Var foo.bar/fib-seq at line 3 src/cljs/foo/bar.cljs
Successfully compiled "js/main.js" in 5.819 seconds.



 Comments   
Comment by Mike Fikes [ 17/Jun/14 7:09 PM ]

An easy workaround is to forward declare. For the example given in the description,

(declare fib-seq)

suffices.

Comment by David Nolen [ 19/Jun/14 10:49 AM ]

Would be happy to take a patch that propagates the def'ed var so that the initializer expression has it during analysis.

Comment by Mike Fikes [ 19/Jun/14 3:58 PM ]

Patch attached.

Note that I'm a new contributor (I signed the online CLA), but I have no experience with the ClojureScript compiler codebase. In other words, increased review for this patch is appropriate IMHO.

Comment by David Nolen [ 19/Jun/14 4:45 PM ]

The patch initially looks OK will give a closer look tomorrow. Thanks!

Comment by Mike Fikes [ 20/Jun/14 9:54 AM ]

Thanks David. Let me know if the patch could use further work. Glad to revise as necessary.

Comment by David Nolen [ 01/Jul/14 9:31 PM ]

fixed https://github.com/clojure/clojurescript/commit/054b0142e303586761d3da01849a2e24896ad7dd

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