local fmt = string.format

local M = {}

function M.tbl_copy(input)

local output = {}

for k, v in pairs(input) do

output[k] = v

end

return output

end

function M.tbl_update(dst, src)

for k, v in pairs(src) do

dst[k] = v

end

return dst

end

function M.tbl_find(t, v)

for i, value in ipairs(t) do

if value == v then

return i

end

end

end

function M.tbl_keys(t)

local keys = {}

for k in pairs(t) do

keys[#keys + 1] = k

end

return keys

end

---@type fun <T> (lbl:string?, v:any, tp:type, optional:boolean?):(value:T)

function M.validate(lbl, v, tp, optional)

local tv = type(v)

if tv == tp or (optional and v == nil) then

return v

end

error(fmt("%s: (%s expected, got %s)", lbl, tp, tv), 3)

end

return M