global.function-or

Signature

v | f == f(v)

The pipe operator applies a value to a function.

Note: because pipes are expressions in Lua, this cannot be used as a statement. To use this operator to cause side-effects, assign the result to a dummy variable.

Examples

print(3 | function(a) return a+4 end) -- 7

for n in {1, 2, 3, 4, 5}
  | lowk.iter.fromarray
  | lowk.iter.filter(function(n) return n%2 == 0 end)
do
  print(n)
end
-- 2
-- 4

local t = {1, 2, 3, 4, 5}
  | lowk.iter.fromarray
  | lowk.iter.filter(function(n) return n%2 == 0 end)
  | lowk.iter.toarray

for i,v in ipairs(t) do
  print(i, v)
end
-- 1    2
-- 2    4