Clojure

Recur around try boxes primitives

Details

  • Type: Enhancement Enhancement
  • Status: Open Open
  • Priority: Minor Minor
  • Resolution: Unresolved
  • Affects Version/s: Release 1.5, Release 1.6
  • Fix Version/s: None
  • Component/s: None

Description

Primitive function and recur variables can't pass through a (try) cleanly; they're boxed to Object instead. This causes reflection warnings for fns or loops that use primitive types.

user=> (set! *warn-on-reflection* true)
true
 
user=> (fn [] (loop [t 0] (recur t)))
#<user$eval676$fn__677 user$eval676$fn__677@3d80023a>
 
user=> (fn [] (loop [t 0] (recur (try t))))
NO_SOURCE_FILE:1 recur arg for primitive local: t is not matching primitive, had: Object, needed: long
Auto-boxing loop arg: t
#<user$eval680$fn__681 user$eval680$fn__681@5419323a>

user=> (fn [^long x] (recur (try x)))
NO_SOURCE_FILE:1 recur arg for primitive local: x is not matching primitive, had: Object, needed: long

CompilerException java.lang.IllegalArgumentException:  recur arg for primitive local: x is not matching primitive, had: Object, needed: long, compiling:(NO_SOURCE_PATH:1:1)

Activity

Alex Miller made changes -
Field Original Value New Value
Description Primitive function and recur variables can't pass through a (try) cleanly; they're boxed to Object instead. This causes reflection warnings for fns or loops that use primitive types.

{{
user=> (set! *warn-on-reflection* true)
true
 
user=> (fn [] (loop [t 0] (recur t)))
#<user$eval676$fn__677 user$eval676$fn__677@3d80023a>
 
user=> (fn [] (loop [t 0] (recur (try t))))
NO_SOURCE_FILE:1 recur arg for primitive local: t is not matching primitive, had: Object, needed: long
Auto-boxing loop arg: t
#<user$eval680$fn__681 user$eval680$fn__681@5419323a>

user=> (fn [^long x] (recur (try x)))
NO_SOURCE_FILE:1 recur arg for primitive local: x is not matching primitive, had: Object, needed: long

CompilerException java.lang.IllegalArgumentException: recur arg for primitive local: x is not matching primitive, had: Object, needed: long, compiling:(NO_SOURCE_PATH:1:1)
}}
Primitive function and recur variables can't pass through a (try) cleanly; they're boxed to Object instead. This causes reflection warnings for fns or loops that use primitive types.

{code}
user=> (set! *warn-on-reflection* true)
true
 
user=> (fn [] (loop [t 0] (recur t)))
#<user$eval676$fn__677 user$eval676$fn__677@3d80023a>
 
user=> (fn [] (loop [t 0] (recur (try t))))
NO_SOURCE_FILE:1 recur arg for primitive local: t is not matching primitive, had: Object, needed: long
Auto-boxing loop arg: t
#<user$eval680$fn__681 user$eval680$fn__681@5419323a>

user=> (fn [^long x] (recur (try x)))
NO_SOURCE_FILE:1 recur arg for primitive local: x is not matching primitive, had: Object, needed: long

CompilerException java.lang.IllegalArgumentException: recur arg for primitive local: x is not matching primitive, had: Object, needed: long, compiling:(NO_SOURCE_PATH:1:1)
{code}
Labels performance typehints compiler performance typehints
Alex Miller made changes -
Issue Type Defect [ 1 ] Enhancement [ 4 ]
Hide
David James added a comment -

Without commenting on the most desirable behavior, the following code does not cause reflection warnings:

user=> (set! *warn-on-reflection* true)
true
user=> (fn [] (loop [t 0] (recur (long (try t)))))
#<user$eval673$fn__674 user$eval673$fn__674@4e56c411>
Show
David James added a comment - Without commenting on the most desirable behavior, the following code does not cause reflection warnings:
user=> (set! *warn-on-reflection* true)
true
user=> (fn [] (loop [t 0] (recur (long (try t)))))
#<user$eval673$fn__674 user$eval673$fn__674@4e56c411>
Hide
Nicola Mometto added a comment -
Show
Nicola Mometto added a comment - Similar ticket http://dev.clojure.org/jira/browse/CLJ-701
Hide
Kevin Downey added a comment - - edited

try/catch in the compiler only implements Expr, not MaybePrimitiveExpr, looking at extending TryExpr with MaybePrimitiveExpr it seems simple enough, but it turns out recur analyzes it's arguments in the statement context, which causes (try ...) to essentially wrap itself in a function like ((fn [] (try ...))), at which point it is an invokeexpr which is much harder to add maybeprimitiveexpr too and it reduces to the same case as CLJ-701

Show
Kevin Downey added a comment - - edited try/catch in the compiler only implements Expr, not MaybePrimitiveExpr, looking at extending TryExpr with MaybePrimitiveExpr it seems simple enough, but it turns out recur analyzes it's arguments in the statement context, which causes (try ...) to essentially wrap itself in a function like ((fn [] (try ...))), at which point it is an invokeexpr which is much harder to add maybeprimitiveexpr too and it reduces to the same case as CLJ-701
Hide
Kevin Downey added a comment -

http://dev.clojure.org/jira/browse/CLJ-701 has a patch that I think solves this

Show
Kevin Downey added a comment - http://dev.clojure.org/jira/browse/CLJ-701 has a patch that I think solves this

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  • Created:
    Updated: