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|
(.module:
[library
[lux #*
["_" test (#+ Test)]
[abstract
[monad (#+ do)]]
[control
["." io (#+ IO)]
["." state (#+ State) ("#\." monad)]]
[data
["." product]
[collection
["." dictionary (#+ Dictionary)]
["." list ("#\." functor fold)]]]
[math
["." random]
[number
["n" nat]
["." i64]]]
[time
["." instant]
["." duration (#+ Duration)]]]]
[\\library
["." /
["/#" // #_
["#" mixin]]]])
(def: (fibonacci recur input)
(/.Memo Nat Nat)
(case input
0 (state\in 0)
1 (state\in 1)
_ (do state.monad
[output_1 (recur (n.- 1 input))
output_2 (recur (n.- 2 input))]
(in (n.+ output_1 output_2)))))
(def: (time function input)
(All [i o] (-> (-> i o) i (IO [Duration o])))
(do io.monad
[before instant.now
.let [output (function input)]
after instant.now]
(in [(instant.span before after)
output])))
(def: milli_seconds
(-> Duration Nat)
(|>> (duration.query duration.milli_second) .nat))
## the wiggle room is there to account for GC pauses
## and other issues that might mess with duration
(def: wiggle_room
Nat
(i64.left_shifted 4 1))
(def: .public test
Test
(<| (_.covering /._)
(do {! random.monad}
[input (|> random.nat (\ ! map (|>> (n.% 5) (n.+ 21))))])
(_.for [/.Memo])
($_ _.and
(_.cover [/.closed /.none]
(io.run
(do io.monad
[.let [slow (/.none n.hash ..fibonacci)
fast (/.closed n.hash fibonacci)]
[slow_time slow_output] (..time slow input)
[fast_time fast_output] (..time fast input)
.let [same_output!
(n.= slow_output
fast_output)
memo_is_faster!
(n.< (n.+ ..wiggle_room (milli_seconds slow_time))
(milli_seconds fast_time))]]
(in (and same_output!
memo_is_faster!)))))
(_.cover [/.open]
(io.run
(do io.monad
[.let [none (/.none n.hash ..fibonacci)
memory (dictionary.empty n.hash)
open (/.open fibonacci)]
[none_time none_output] (..time none input)
[open_time [memory open_output]] (..time open [memory input])
[open_time/+1 _] (..time open [memory (inc input)])
.let [same_output!
(n.= none_output
open_output)
memo_is_faster!
(n.< (n.+ ..wiggle_room (milli_seconds none_time))
(milli_seconds open_time))
incrementalism_is_faster!
(n.< (n.+ ..wiggle_room (milli_seconds open_time))
(milli_seconds open_time/+1))]]
(in (and same_output!
memo_is_faster!
incrementalism_is_faster!)))))
(_.cover [/.memoization]
(let [memo (<| //.mixin
(//.inherit /.memoization)
(: (//.Mixin Nat (State (Dictionary Nat Nat) Nat))
(function (factorial delegate recur input)
(case input
(^or 0 1) (\ state.monad in 1)
_ (do state.monad
[output' (recur (dec input))]
(in (n.* input output')))))))
expected (|> (list.indices input)
(list\map inc)
(list\fold n.* 1))
actual (|> (memo input)
(state.run (dictionary.empty n.hash))
product.right)]
(n.= expected actual)))
)))
|
