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[CTYP-326] Let-aliasing breaks flow inference for results of `class` Created: 03/Jul/17  Updated: 03/Dec/17

Status: Open
Project: core.typed
Component/s: Core type system
Affects Version/s: None
Fix Version/s: Backlog

Type: Defect Priority: Blocker
Reporter: Ambrose Bonnaire-Sergeant Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: let-aliasing, regression


 Description   

The following code complains a NPE is possible from .isArray,
but clearly the assertion prevents that. This issue is related
to let-aliasing, probably related to core.typed not knowing how
to update the type of `c` with the information that it's class
is non-nil.

(fn [a :- t/Any]
  (let [c (class a)
        _ (assert c)]
    (.isArray c)))





[CTYP-270] "Method code too large!" with protocols (more than 38 functions in the protocol) Created: 17/Aug/15  Updated: 03/Dec/17

Status: Open
Project: core.typed
Component/s: Clojure Checker
Affects Version/s: 0.3.11
Fix Version/s: Backlog

Type: Defect Priority: Blocker
Reporter: Johan Gall Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

You should be able to get the error with lein typed check on this.

https://gist.github.com/freakhill/2df1117738362d602672



 Comments   
Comment by Johan Gall [ 17/Aug/15 11:46 PM ]

"Method coDe too large!"

more than 39 functions





[CTYP-241] Let-aliased variables of plain Map lookups should update original map Created: 26/Jun/15  Updated: 03/Dec/17

Status: Open
Project: core.typed
Component/s: Core type system
Affects Version/s: None
Fix Version/s: Backlog

Type: Defect Priority: Blocker
Reporter: Mark Feeney Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: let-aliasing, regression
Environment:

After commit https://github.com/clojure/core.typed/commit/960802



 Description   

Problem

Let-aliasing means we completely rely on the original binding's
type to find the type for locals derived from lookups on it. If
occurrence typing doesn't update the original binding, then even
very simple control flow does not register.

For example, in core.typed 0.3.7, the following code registers
e as an alias of (Key :foo)m.

(fn [m :- (Map Any Str)] :- String
  (let [e (:foo m)]
    (if e e "asdf")))
;;        ^
;;  Expected Str, actual (U nil Str)

e contains the correct propositions and object, however
update ignores propositions that update non-HMap types.

So in the test position, m is still of type (Map Any Str), which means path-type
infers Any for its aliased object (above). (Note: path-type should infer slightly better
types here, eg., this should return (U nil Str)).

Solution

The update case for keyword invocations on non-HMaps
need to intersect its known HMap type.

We now make it an error to assign an object to the result of looking up
a possibly-mutable map. ie.,

(fn [a :- Any] (:foo a))

has no object.

Correspondingly, update will throw an error if told to update via a keyword lookup
on a map type that is not a subtype of (U nil (Map Any Any)).

We cannot have objects that might be wrong — the formalism asserts that in

G |- e : t ; v+ | v- ; o}}, where G |- p and p |- e || v, that o = empty, or p(o) = v.

That means looking up an object o of an expression e must always
result in exactly its evaluation v. If we gave an object to

(fn [a :- Any] (:foo a))

that means two invocations of

((fn [a :- Any] (:foo a)) m)

must return exactly the same value — for a mutable m this is clearly false.

Interestingly, this has worked fine in practice until let-aliasing, by compensating
in the update function. We basically only update types that are immutable, checked
at the last minute in update.

Briefly, to handle this idea of "temporarily fake" objects, we probably need a predicate to validate
whether an object should be taken "seriously" as an actual, immutable, path. Then the formalism
might read:

G |- e : t ; v+ | v- ; o}}, where G |- p and p |- e || v, that o = empty, or if serious(o) then p(o) = v.

More information

Discussion here: https://groups.google.com/d/msg/clojure-core-typed/WO8dpY63N2Q/7UWBViNiIYEJ

git bisect code

(do (require '[clojure.core.typed :as t]) (t/cf (t/fn [m :- (t/Map t/Kw String)] :- String (or (:foo m) "asdf"))))

This stopped type checking after https://github.com/clojure/core.typed/commit/9608027bfaf4be268cfa12486c5ae6615d8517f1

bisect result:

9608027bfaf4be268cfa12486c5ae6615d8517f1 is the first bad commit
commit 9608027bfaf4be268cfa12486c5ae6615d8517f1
Author: Ambrose Bonnaire-Sergeant <...@gmail.com>
Date: Sat Jan 3 00:05:23 2015 +0000

enable aliasing support

Pull request:

Patch:
Commmit:
Release:



 Comments   
Comment by Ambrose Bonnaire-Sergeant [ 18/Jul/15 2:21 AM ]

Minimal failing case:

(is-tc-e (fn [m :- (Map Kw Str)] :- Str 
           (let [e (:foo m)]
             (if e e "asdf"))))
;;                 ^
;;    Expected Str, actual (U nil Str)

This happens because let-aliasing relies on path-type solely to get a type for `e` and the type is not updated sufficiently based on this control flow.

Work started here: https://github.com/typedclojure/core.typed/pull/26





[CTYP-231] (Array X) is broken and undocumented Created: 23/Jun/15  Updated: 03/Dec/17

Status: Open
Project: core.typed
Component/s: Clojure Checker
Affects Version/s: None
Fix Version/s: Backlog

Type: Defect Priority: Blocker
Reporter: Marc O'Morain Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None


 Description   

There is no documentation about (Array X) in the API docs: http://clojure.github.io/core.typed/#clojure.core.typed - it was hard to find our that such a thing existed.



 Comments   
Comment by Ambrose Bonnaire-Sergeant [ 23/Jun/15 8:26 AM ]

Unfortunately it's intentional. It's a long standing issue, one that I've thought long and hard about, but Arrays broken right now. The main problem is that there is no distinction between an array of boxed values and an array of unboxed values – you can upcast from one the other.

I will put this near the top of the list of things to do.

Comment by Marc O'Morain [ 23/Jun/15 8:39 AM ]

We have a few uses of Array in our code-base. The few I have been touching today are for annotating clojure.java.io signatures. We don't use the byte[] forms of the functions at present, so we should be OK for now.

Thanks

Comment by Ambrose Bonnaire-Sergeant [ 23/Jun/15 8:50 AM ]

The implementation is fast and loose about the distinction of byte and Byte too – they're pretty much identical, since Clojure does the appropriate coercions at runtime. Also be careful about that.





[CTYP-223] checking clojure.core/keep produces Internal Error--Cannot resolve type: Option Created: 31/May/15  Updated: 03/Dec/17

Status: Open
Project: core.typed
Component/s: None
Affects Version/s: None
Fix Version/s: Backlog

Type: Defect Priority: Blocker
Reporter: Vince Broz Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None
Environment:

org.clojure/core.typed "0.2.92"



 Description   

How to reproduce:

(t/cf (t/fn [] (keep even? [1 2 3])))

Observed result:

DEPRECATED SYNTAX (NO_SOURCE_PATH): All syntax is deprecated, use clojure.core.typed/All
Type Error (NO_SOURCE_PATH:1:16) Internal Error (NO_SOURCE_PATH:1:16) Cannot resolve type: Option
Hint: Is Option in scope?
Hint: Has Option's annotation been found via check-ns, cf or typed-deps?

ExceptionInfo Type Checker: Found 1 error  clojure.core/ex-info (core.clj:4403)

Expected result:

(t/ASeq Integer) or something like that, I would guess.

Details:

broz@macmicro:~/src/foo$ lein try org.clojure/core.typed "0.2.92"
nREPL server started on port 63244 on host 127.0.0.1 - nrepl://127.0.0.1:63244
REPL-y 0.3.5, nREPL 0.2.6
Clojure 1.6.0
Java HotSpot(TM) 64-Bit Server VM 1.8.0_40-b26
    Docs: (doc function-name-here)
          (find-doc "part-of-name-here")
  Source: (source function-name-here)
 Javadoc: (javadoc java-object-or-class-here)
    Exit: Control+D or (exit) or (quit)
 Results: Stored in vars *1, *2, *3, an exception in *e

user=> (require ['clojure.core.typed :as 't])
nil
user=> (t/cf (t/fn [] (keep even? [1 2 3])))
Initializing core.typed ...
Building core.typed base environments ...
Finished building base environments
"Elapsed time: 9649.842771 msecs"
core.typed initialized.
DEPRECATED SYNTAX (NO_SOURCE_PATH): All syntax is deprecated, use clojure.core.typed/All
Type Error (NO_SOURCE_PATH:1:16) Internal Error (NO_SOURCE_PATH:1:16) Cannot resolve type: Option
Hint: Is Option in scope?
Hint: Has Option's annotation been found via check-ns, cf or typed-deps?

ExceptionInfo Type Checker: Found 1 error  clojure.core/ex-info (core.clj:4403)
user=>





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