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local F = {}
--- Returns {a} if it is not nil, otherwise returns {b}.
---
---@param a
---@param b
function F.if_nil(a, b)
if a == nil then return b end
return a
end
-- Use in combination with pcall
function F.ok_or_nil(status, ...)
if not status then return end
return ...
end
-- Nil pcall.
function F.npcall(fn, ...)
return F.ok_or_nil(pcall(fn, ...))
end
--- Wrap a function to return nil if it fails, otherwise the value
function F.nil_wrap(fn)
return function(...)
return F.npcall(fn, ...)
end
end
--- like {...} except preserve the length explicitly
function F.pack_len(...)
return {n=select('#', ...), ...}
end
--- like unpack() but use the length set by F.pack_len if present
function F.unpack_len(t)
return unpack(t, 1, t.n)
end
return F
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