czzc/table.lua


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local M = {}

-- shallow copies a table, dst optional.
M.copy = function(src, dst)
    dst = dst or {}
    for k, v in pairs(src) do
        dst[k] = v
    end
    return dst
end

-- recursively copies a table, dst optional.
-- might implode for infinitely nested tables.
M.deepcopy = function(src, dst)
    dst = dst or {}
    -- convenience.
    if type(src) ~= "table" then return src end
    for k, v in pairs(src) do
        dst[k] = M.deepcopy(v)
    end
    return dst
end

-- replaces all values of a table with fn(value).
M.map = function(fn, tbl)
    local res = M.copy(tbl)
    for k, v in pairs(tbl) do
        res[k] = fn(v)
    end
    return res
end

return M