mirror of
https://github.com/1bardesign/batteries.git
synced 2024-11-14 20:04:34 +00:00
added functional.map_pairs
This commit is contained in:
parent
8b7769319e
commit
bde95f208f
@ -318,6 +318,24 @@ end
|
||||
|
||||
functional.map_chain = functional.chain
|
||||
|
||||
--maps a sequence {a, b, c, d} -> { f(a, b), f(a, c), f(a, d), f(b, c), f(b, d), f(c, d) }
|
||||
-- ie all distinct pairs are mapped, useful for any N^2 dataset (eg finding neighbours)
|
||||
|
||||
function functional.map_pairs(t, f)
|
||||
local result = {}
|
||||
for i = 1, #t do
|
||||
for j = i+1, #t do
|
||||
local a = t[i]
|
||||
local b = t[j]
|
||||
local v = f(a, b)
|
||||
if v ~= nil then
|
||||
table.insert(result, v)
|
||||
end
|
||||
end
|
||||
end
|
||||
return result
|
||||
end
|
||||
|
||||
|
||||
-----------------------------------------------------------
|
||||
--generating data
|
||||
|
Loading…
Reference in New Issue
Block a user