JuliaLang/julia

map! only works on AbstractArray

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#38,344 opened on Nov 7, 2020

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 (4 comments) (2 reactions) (0 assignees)Julia (5,773 forks)batch import
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Description

Any reason for restricting the signature of map! to AbstractArray? I don't see why this shouldn't work:

julia> a, b = [1,2], (3,4)
([1, 2], (3, 4))

julia> map(*, a, b)
2-element Vector{Int64}:
 3
 8

julia> map!(*, a, a, b)
ERROR: MethodError: no method matching map!(::typeof(*), ::Vector{Int64}, ::Vector{Int64}, ::Tuple{Int64, Int64})
Closest candidates are:
  map!(::F, ::AbstractArray, ::AbstractArray) where F at abstractarray.jl:2259
  map!(::F, ::AbstractArray, ::AbstractArray, ::AbstractArray) where F at abstractarray.jl:2303
  map!(::F, ::AbstractArray, ::AbstractArray...) where F at abstractarray.jl:2350
  ...
Stacktrace:
 [1] top-level scope
   @ REPL[12]:1

Contributor guide

Research direction
Understand the current implementation of `map!` in abstractarray.jl and propose a generalization to work with any iterable.
Tech stack
julia
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3
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1-3 hours
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Clear
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Julia
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60