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Diffstat (limited to 'gamemode/utility/fn.lua')
| -rw-r--r-- | gamemode/utility/fn.lua | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/gamemode/utility/fn.lua b/gamemode/utility/fn.lua new file mode 100644 index 0000000..7c53150 --- /dev/null +++ b/gamemode/utility/fn.lua @@ -0,0 +1,229 @@ +--[[ + Various functional programming bits and bobs + Function signatures: + fn.curry(func,...) :: function(...) :: any + fn.map(tbl,func) :: table + fn.compose(...) :: function(...) :: any + fn.filter(tbl,func) :: table + fn.zip(...) :: table + fn.fill(arg,times) :: table + fn.amalg(...) :: function(...) :: any + fn.cycle(tbl) :: table + fn.fold(tbl) :: function(func(T1,T2)::T) :: T + fn.flatten(tbl) :: table +]] +--AddCSLuaFile() +local fn = {} + +if table.Copy == nil then + function table.Copy(tbl) + local ntbl = {} + for k,v in pairs(tbl) do ntbl[k] = v end + return ntbl + end +end + +--[[ + Puts some arguments "in" a function so that it can be called with some number fewer arguments. + Ex: + local f = include("nightz/gamemode/utility/functional.lua") + local debugprint = f.curry(print,"[DEBUG]") + debugprint("Hello, world!") + --Is the same as + print("[DEBUG]","Hello, world!") +]] +function fn.curry(func,...) + local nargs = {...} + return function(...) + for k,v in pairs({...}) do + nargs[k + #nargs] = v + end + func(unpack(nargs)) + end +end + +--[[ + calls each function from first to last on every element of tbl, and returns a table with the function called. + Ex: + local f = include("nightz/gamemode/utility/functional.lua") + local playerents = { + Player(1), + Player(2), + Player(3) + } + local getname = function(ply) return ply:Nick() end + local playernames = f.map(playerents) + --playernames is now a table { + "Player1_name", + "Player2_name", + "Player3_name" + } +]] +function fn.map(tbl,...) + local nfuncs = {...} + local ntbl = table.Copy(tbl) + for i,j in pairs(nfuncs) do + for k,v in pairs(tbl) do + ntbl[k] = j(v) + end + end + return ntbl +end + +--[[ + Calls a list of functions, starting with the last, going to the first, and passes the arguments as whatever was outputed from the previous function. + Ex: + local f = include("nightz/gamemode/utility/functional.lua") + local printf = f.compose(print,string.format) + printf("Thanks, I love %d",5) + --Is the same as + print(string.format("Thanks, I love %d", 5)) +]] +function fn.compose(...) + local nargs = {...} + local n = #nargs + local lastresult + return function(...) + lastresult = {...} + while n > 0 do + lastresult = {nargs[n](unpack(lastresult))} + n = n - 1 + end + end +end + +--[[ + Removes elements from tbl for which func returns nil or false (returns new table). this WILL mess up order for arrays. + Ex: + local f = include("nightz/gamemode/utility/functional.lua") + local sometable = { + 1,3,4,5,5,6,7,8,9 + } + for k,v in pairs(sometable) do print(k,":",v) end + --this will print: + 1:1 + 2:3 + 3:4 + 4:5 + 5:5 + 6:6 + 7:7 + 8:8 + 9:9 + local function iseven(k) return k%2 == 0 end + local evens = f.filter(sometable,iseven) + for k,v in pairs(evens) do print(k,":",v) end + --this will print: + 3:4 + 6:6 + 8:8 +]] +function fn.filter(tbl,func) + local ntbl = table.Copy(tbl) + for k,v in pairs(ntbl) do + if not func(v) then + ntbl[k] = nil + end + end +end + +--Takes n tables that have the same indexes, and returns a table that for every index, it's value is {tbl1[index],tbl2[index],...,tbln[index]} +function fn.zip(...) + local nargs = {...} + local ntbl = table.Copy(nargs[1]) + for k,v in pairs(ntbl) do + local ttbl = {} + for i,j in pairs(nargs) do + ttbl[#ttbl + 1] = v[i] + end + ntbl[k] = ttbl + end + return ntbl +end + +--Creates a table filled with <times> number of arg +function fn.fill(arg,times) + local ret = {} + for i = 1,times do + ret[i] = arg + end + return ret +end + +--Calls all functions passed in order, and returns all results for all functions called.S +function fn.amalg(...) + local nargs = {...} + return function(...) + local nret = {} + for k,v in pairs(nargs) do + local tret = {v(unpack({...}))} + for i,j in pairs(tret) do + nret[#nret + 1] = j + end + end + return unpack(nret) + end +end + +--[[ +Cycles a table infinitely + Ex: + local sometbl = {1,2,3} + fn.cycle(sometbl) + for i = 1, 100 do + print(sometbl[i]) + end + Outputs: + 1 + 2 + 3 + 1 + 2 + : + : + : +]] +function fn.cycle(tbl) + local ntbl = table.Copy(tbl) + local tbllen = #tbl + local mt = { + __index = function(self, ind) + local id = (ind % tbllen) + 1 + return tbl[id] + end + } + setmetatable(ntbl,mt) + return ntbl +end + +--[[ + Iterates over a table applying a function to each item + Ex: + local sometbl = {1,4,5,6,7,10} + local add = function(a,b) return a + b end + local sum = fn.fold(sometbl)(add) + print(sum) + Output: + 33 +]] +function fn.fold(tbl) + return function(func) + local running = tbl[1] + for k = 2, #tbl do + running = func(running,tbl[k]) + end + return running + end +end + +--[[ + Returns an array-type table +]] +function fn.flatten(tbl) + local ret = {} + for k,v in pairs(tbl) do + ret[#ret + 1] = v + end + return ret +end +return fn |