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Added perf rules
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@jonase
jonase committed Mar 19, 2012
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5 changes: 5 additions & 0 deletions src/jonase/kibit/rules/performance.clj
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(ns jonase.kibit.rules.performance
(:use [jonase.kibit.rules.util :only [defrules]]))

(defrules rules
[(reduce + ?coll) (apply + ?coll)])

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@cgriego

cgriego Nov 27, 2012

Going from my (limited) understanding of Clojure and going off the comment in the current version of this file compared against the style of ocmments in other files, I believe this rule might be backwards? As written it's recommending apply instead of reduce.

Edit from Paul // OhPauleez

This rule is correct. Addition for n-ary args is always faster than reduce, because addition is an n-ary operation (and it avoids unnecessary allocations).

user=> (time (reduce + (range 100)))
"Elapsed time: 1.42 msecs"
4950
user=> (time (apply + (range 100)))
"Elapsed time: 0.807 msecs"
4950

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