A Lua repl that copies local variables onto globals for inspection

debug_repl.lua

local torch_repl = repl

function repl(restoreGlobals)
    -- copied from http://stackoverflow.com/questions/33068607/how-can-i-use-the-torch-repl-for-debugging
    require 'trepl'
    restoreGlobals = restoreGlobals or false

    -- optionally make a shallow copy of _G
    local oldG = {}
    if restoreGlobals then
        for k, v in pairs(_G) do
            oldG[k] = v
        end
    end

    -- copy upvalues to _G
    local i = 1
    local func = debug.getinfo(2, "f").func
    while true do
        local k, v = debug.getupvalue(func, i)
        if k ~= nil then
            _G[k] = v
        else
            break
        end
        i = i + 1
    end

    -- copy locals to _G
    local i = 1
    while true do
        local k, v = debug.getlocal(2, i)
        if k ~= nil then
            _G[k] = v
        else
            break
        end
        i = i + 1
    end

    torch_repl()

    if restoreGlobals then
        _G = oldG
    end
end