[CLJ-1075] deftype: compiler error on set! for mutable field Created: 24/Sep/12 Updated: 03/Dec/12 Resolved: 03/Dec/12 |
|
| Status: | Closed |
| Project: | Clojure |
| Component/s: | None |
| Affects Version/s: | Release 1.4 |
| Fix Version/s: | None |
| Type: | Defect | Priority: | Major |
| Reporter: | Gunnar Völkel | Assignee: | Unassigned |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Description |
|
The following code demonstrates the error in a minimal example: (defprotocol IBlob (do-sth [this, x])) (deftype Blob [^{:volatile-mutable true} a] IBlob (do-sth [this, x] (try (/ 1 x) (catch Throwable t (set! a (inc a)))) (inc x))) (deftype Blob2 [^{:volatile-mutable true} a] IBlob (do-sth [this, x] (try (/ 1 x) (catch Throwable t (set! a (inc a)))))) Compiling Blob results in the following exception:
Compiling Blob2 works as expected. |
| Comments |
| Comment by Chouser [ 24/Sep/12 9:13 AM ] |
(defmethod print-method clojure.lang.Compiler$LocalBinding [^clojure.lang.Compiler$LocalBinding o w] (.write w (str "#<LB " (binding [*print-meta* true] (pr-str {:sym (.-sym o) :tag (.-tag o) :idx (.-idx o) :name (.-name o) :isArg (.-isArg o) :canBeCleared (.canBeCleared o) :recurMistmatch (.-recurMistmatch o)})) ">"))) (defmacro prn-env [] (doseq [[_ lb] &env] (prn lb))) (deftype T [^:volatile-mutable x] clojure.lang.IDeref (deref [this] (try (catch Exception e (prn-env) (set! x 0))) 1)) #<LB {:sym ^{:volatile-mutable true} x, :tag nil, :idx -1, :name "x", :isArg false, :canBeCleared true, :recurMistmatch false}> #<LB {:sym e, :tag Exception, :idx 3, :name "e", :isArg false, :canBeCleared true, :recurMistmatch false}> #<LB {:sym this, :tag compile__stub.user.T, :idx 0, :name "this", :isArg false, :canBeCleared true, :recurMistmatch false}> CompilerException java.lang.IllegalArgumentException: Cannot assign to non-mutable: x, compiling:(NO_SOURCE_PATH:1) |
| Comment by Gunnar Völkel [ 24/Sep/12 9:21 AM ] |
|
As a workaround you can create a setter method for that field, e.g. (set-a [this, na] (set! a na))
|
| Comment by Andy Fingerhut [ 24/Sep/12 10:06 AM ] |
|
Is this the same issue as |
| Comment by Gunnar Völkel [ 04/Oct/12 4:15 AM ] |
|
That one looks very similar, yes. |
| Comment by Timothy Baldridge [ 03/Dec/12 10:52 AM ] |
|
closing as duplicate of |