RosettaCodeData/Task/Matrix-transposition/Lua/matrix-transposition-2.lua

28 lines
642 B
Lua

function map(f, a)
local b = {}
for k,v in ipairs(a) do b[k] = f(v) end
return b
end
function mapn(f, ...)
local c = {}
local k = 1
local aarg = {...}
local n = #aarg
while true do
local a = map(function(b) return b[k] end, aarg)
if #a < n then return c end
c[k] = f(unpack(a))
k = k + 1
end
end
function apply(f1, f2, a)
return f1(f2, unpack(a))
end
xy = {{1,2,3,4},{1,2,3,4},{1,2,3,4}}
yx = apply(mapn, function(...) return {...} end, xy)
print(table.concat(map(function(a) return table.concat(a,",") end, xy), "\n"),"\n")
print(table.concat(map(function(a) return table.concat(a,",") end, yx), "\n"))