https://github.com/colinfang/memoize.jl
Type inference friendly generic function memoization
https://github.com/colinfang/memoize.jl
Last synced: 2 months ago
JSON representation
Type inference friendly generic function memoization
- Host: GitHub
- URL: https://github.com/colinfang/memoize.jl
- Owner: colinfang
- License: other
- Created: 2017-04-09T20:52:05.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2017-04-09T23:05:16.000Z (about 8 years ago)
- Last Synced: 2025-02-10T12:42:54.186Z (4 months ago)
- Language: Julia
- Homepage:
- Size: 4.88 KB
- Stars: 4
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: Readme.md
- License: LICENSE.md
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README
# Memoize.jl
[](https://travis-ci.org/colinfang/Memoize.jl)
## Overview
This package provides basic support for type inference friendly generic function memoization. It allows to customize cache key from function arguments.
- Type inference friendly
- Cache invalidation
- Each method of a generic function has its own cache
- custom cache key
- Recursive functions
## Limitation
- It doesn't support keyword arguments or default arguments.
- It only support standard function definition with return type annotated.
- Parametric functions are not supported.
- It uses `Dict` for cache, not `ObjectIdDict`.
- Work best with Julia v0.6 since [automatic recompilation of dependent functions](https://github.com/julialang/julia/issues/265) is fixed.
## Exposed Verbs
```julia
export @memoize, clear_cache, get_cache
```
## Usage
```julia
Pkg.clone("https://github.com/colinfang/Memoize.jl.git")
using Memoize
@memoize function fib(x::Int)::Int
x <= 2 ? x : fib(x - 1) + fib(x - 2)
end
@memoize function fib(x::Float64, y)::Float64
x + y
end
julia> fib(3), fib(1.0, 5)
(3, 6.0)
julia> @time fib(100)
0.000073 seconds (199 allocations: 14.166 KiB)
juila> @time fib(100)
0.000005 seconds (5 allocations: 176 bytes)
julia> get_cache(fib)
Dict{Tuple,Dict} with 2 entries:
(Float64, Any) => Dict{Any,Float64}(Pair{Any,Float64}((1.0, 5), 6.0))
(Int64,) => Dict{Any,Int64}(Pair{Any,Int64}(68, 117669030460994),Pair{A…
julia> clear_cache(fib)
julia> get_cache(fib)
Dict{Tuple,Dict} with 2 entries:
(Float64, Any) => Dict{Any,Float64}()
(Int64,) => Dict{Any,Int64}()
julia> @time fib(100)
0.000027 seconds (5 allocations: 176 bytes)
julia> Base.return_types(fib, (Int,))
1-element Array{Any,1}:
Int64
# Assume `y` doesn't affect the result.
function Memoize.make_key(::typeof(fib), x, y)
x
end
julia> fib(1.0, 5)
6.0
julia> fib(1.0, 6)
6.0
```
## Macro Expand
```julia
@macroexpand Memoize.@memoize function fib(x::Int)::Int
x <= 2 ? x : fib(x - 1) + fib(x - 2)
end
quote
let
local #55#pt = (Int,)
local cache = (Memoize.get!)((Memoize.Dict){Memoize.Any, Int}, Dict{Tuple,Dict}(), #55#pt)
global fib
function fib(x::Int)::Int
function unmemoized()::Int
if x <= 2
x
else
fib(x - 1) + fib(x - 2)
end
end
key = (Memoize.make_key)(fib, x)
(Memoize.get!)(unmemoized, cache, key)
end
end
end
```