dawbarton

function predict(prevtarget::Vector{T}, s = 1.0) where T <: AbstractArray
    secant = prevtarget[end] - prevtarget[end-1]
    (prevtarget[end] + s*secant, secant)
end

function correct!(expt, target::AbstractVector)
    correct!(expt, target, zeros(target))
end

dawbarton

using SoftGlobalScope
import REPL

const USE_REVISE = false

function replace_active_backend()
    backend = Base.active_repl_backend
    # Kill the existing REPL backend
    put!(backend.repl_channel, (nothing, -1))
    # Copied from REPL/src/REPL.jl: start_repl_backend