andyferris

function mapreduce(f, op, a::AbstractArray; init)
    out = Ref(init)
    foreach(a) do x
        out[] = op(f(x), out[])
    end
    return out[]
end

function map(f, a::AbstractArray)
    out = similar(a, Core.Compiler.return_type(f, Tuple{eltype(a)}))

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function Base.Dict{K,V}(::Uninitialized, inds) where {K, V}
    set = Set{K}(inds)
    d = set.dict
    n = length(d.keys)
    Dict{K,V}(d.slots, d.keys, Vector{V}(uninitialized, n), d.ndel, d.count, d.age, d.idxfloor, d.maxprobe)
end

function Base.Dict{K,V}(::Uninitialized, inds::Set{K}) where {K, V}
    d = inds.dict
    n = length(d.keys)

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# size versions
Array{T}(2, 3)
Array{T}(blah, 2, 3)
Array{T}((2,3)) 
Array{T}(blah, (2,3))
Array{T}(size = (2,3))
Array{T}(blah, size = (2,3))

# indices versions
Array{T}(OneTo(2), OneTo(3)) # is OneTo(2) a `blah` or the first index?

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struct Vec{N,T}
    data::NTuple{N,T}
end

@inline function Base.getindex(v::Vec{N}, i::Int) where {N}
    @boundscheck if i < 1 || i > N
        throw(BoundsError(v,i))
    end
    @inbounds return v.data[i]
end

andyferris

# "bespoke" generated functions
Pkg.checkout("StaticArrays","master")
using StaticArrays
f(v) = @inbounds return v[v]
v = SVector{3,Int}((1,2,3))

# results:
julia> @code_native f(v)
	.text
Filename: REPL[3]

andyferris

module Maybe

export ?

immutable ?{T}
    hasvalue::Bool
    value::T

    ?() = new(false)
    ?(x::T) = new(true, x)

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module SimpleSymbolic

immutable S
    x::Any
end

Base.show(io::IO, s::S) = print(io, s.x)

function Base.:+(s1::S, s2::S)
    if s1.x == 0

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module ImageTransformations

using CoordinateTransformations
import CoordinateTransformations.transform

export TransformedArray, ImageTransformation


abstract Filter
immutable NearestNeighbourFilter <: Filter; end

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module Quaternions

# This is a type of number
immutable Quaternion{T <: Real} <: Number
   s::T
   x::T
   y::T
   z::T
end