I want to make a translator that translates R U R' U' into r^ u< rv u>. This is very difficult because R' has R in it. So when I try to use this, it spits a result back to me like
put in your algorithm: R U R' U'
r^ u< r^' u<'
Not a very human way of doing it. I think this is because R is a substring of R', but this is what I have been told. I am using this translation thingy from a package called luastring. The dev of luastring won't help me, and this question is too advanced for everyone on the discord server. This is what I have tried so far.
io.write("put in your algorithm: ")
local alg = io.read()
function split(str, pat)
local t = {}
local fpat = "(.-)" .. pat
local last_end = 1
local s, e, cap = str:find(fpat, 1)
while s do
if s ~= 1 or cap ~= "" then table.insert(t, cap) end
last_end = e + 1
s, e, cap = str:find(fpat, last_end)
end
if last_end <= #str then
cap = str:sub(last_end)
table.insert(t, cap)
end
return t
end
-- table stuff so we can see
local moves = {"R", "U", "L", "F", "D", "B", "M", "E", "S", "R'", "U'", "L'", "F'", "D'", "B'", "M'", "E'", "S'"}
local neomoves = {"r^", "u<", "lv", "f>", "d>", "b<", "mv", "e>", "s>", "rv", "u>", "l^", "f<", "d<", "b>", "m^", "e<", "s<"}
local string = require("luastring")
local translation_table = {
["R'"] = "rv", ["U'"] = "u<", ["L'"] = "lv", ["F'"] = "f>", ["D'"] = "d>", ["B'"] = "b<", ["M'"] = "mv", ["E'"] = "e>", ["S'"] = "s>", ["R"] = "r^", ["U"] = "u<", ["L"] = "lv", ["F"] = "f>", ["D"] = "d>", ["B"] = "b<", ["M"] = "mv", ["E"] = "e>", ["S"] = "s>"
}
-- translate the moves to neomoves
local translated = string.translate(alg, translation_table)
print(translated)
What on earth do I have to do to let Lua know what it is supposed to do?
As your translated string is lower case and the source string is upper case you can simply translate R' befor you translate R.
You only need to split your translation_table into two.
Also you can simply use Lua's standard string.gsub for this. I don't see why you would use luastring here.
Simplified example:
local str = "R' R R' R'"
local t_a = {["R'"] = "rv"}
local t_b = {["R"] = "r^"}
print((str:gsub("%S+", t_a):gsub("%S+", t_b)))
Related
So I want to take an input like R U R' U' and turn it into a table that contains
R
U
R'
U'
I haven't found an example of code that worked. I have tried this solution from codegrepper, and it didn't work. I have not come up with anything else in my head but my general program, which is supposed to take an input like R and find its place in a table. If R is 1, then it will take the value 1 from another table, which will have the r^ as value 1. Then it will do this with the rest and print it when it is done. So if there is an optimization with this that could make it all quicker than I would like to see it. Thanks and goodbye.
function split(str, pat)
local t = {}
local fpat = "(.-)" .. pat
local last_end = 1
local s, e, cap = str:find(fpat, 1)
while s do
if s ~= 1 or cap ~= "" then table.insert(t, cap) end
last_end = e + 1
s, e, cap = str:find(fpat, last_end)
end
if last_end <= #str then
cap = str:sub(last_end)
table.insert(t, cap)
end
return t
end
then split it with split(var," ")
local myString = "R U R' U'"
local myTable = {}
for e in string.gmatch(myString, "%S+") do
table.insert(myTable, e)
end
Lua Users Wiki
s:gmatch(pattern)
This returns a pattern finding iterator. The iterator will search
through the string passed looking for instances of the pattern you
passed.
First you need to match all the space-separated parts. You can do this using gmatch. Then you can insert these parts as keys in a hash table, the value being the one-indexed index of the occurrence:
local str = "R U R' U'"
local index = 1
local last_occurrence = {}
for match in str:gmatch"%S+" do
last_occurrence[match] = index
index = index + 1
end
Now you can use your "other table" to obtain the value in constant time:
local other_table = {"r^"}
local value = other_table[last_occurrence.R] -- "r^"
I see similar answers to this question given in different programming languages like Haskell and Python but all of them use build-in functionality that Lua doesn't have, so please don't mark this question as duplicate.
Let's say i have two tables like bellow:
table1 = {A,B,C}
table2 = {D,E,F}
I would like to find all unique ways of matching the items from two tables, the answer should be (in informal notation):
AD,BE,CF
AD,BF,CE
AE,BD,CF
AE,BF,CD
AF,BD,CE
AF,BE,CD
so the answer will store in a table that table[1] would be {{A, D}, {B, E}, {C, F}} and so on.
tables length can be anything but both will be the same size.
we can get all shuffles via induction (not the fastest way, but pretty easy to write/understand)
local function deepcopy(orig)
local copy
if type(orig) == 'table' then
copy = {}
for orig_key, orig_value in next, orig, nil do
copy[deepcopy(orig_key)] = deepcopy(orig_value)
end
setmetatable(copy, deepcopy(getmetatable(orig)))
else
copy = orig
end
return copy
end
local function get_shuffles(N)
if N == 1 then
return {{1}}
end
local shuffles = get_shuffles(N-1)
local result = {}
for index = 1, #shuffles do
local shuffle = shuffles[index]
for position = 1, #shuffle do
local new_shuffle = deepcopy(shuffle)
table.insert(new_shuffle, position, N)
table.insert(result, new_shuffle)
end
local new_shuffle = deepcopy(shuffle)
table.insert(new_shuffle, N)
table.insert(result, new_shuffle)
end
return result
end
table1 = {"A", "B", "C"}
table2 = {"D","E", "F"}
assert(#table1 == #table2)
local result = {}
local shuffles = get_shuffles(#table1)
for index = 1, #shuffles do
local shuffle = shuffles[index]
local part = {}
for i = 1, 3 do
table.insert(part, {})
table.insert(part[i], table1[i])
table.insert(part[i], table2[shuffle[i]])
end
table.insert(result, part)
end
for index = 1, #result do
print(result[index][1][1], result[index][1][2], result[index][2][1], result[index][2][2], result[index][3][1], result[index][3][2])
end
function get_all_combinations(arr1, arr2)
local n, e, all_comb = #arr1, {}, {}
for j = 1, n do
e[j] = arr2[j]
end
local function generate(m)
if m <= 1 then
local comb = {}
all_comb[#all_comb + 1] = comb
for j = 1, n do
comb[j] = arr1[j]..e[j] -- it should be {arr1[j], e[j]} to fulfill your requirements
end
else
for j = 1, m do
generate(m - 1)
local k = j < m and m % 2 == 1 and 1 or j
e[k], e[m] = e[m], e[k]
end
end
end
generate(n)
return all_comb
end
for i, v in ipairs(get_all_combinations({"A", "B", "C"}, {"D", "E", "F"})) do
print(i, table.concat(v, ";"))
end
An alternate way of doing it is with the following code. This was written to help with a game (Typeshift) to discover all possible combinations of variable groups of letters. I've modified it to fit your example, though.
-- table array: { {1, 2}, {3, 4}, {5, 6} }
-- Should return { 135, 136, 145, 146, 235, 236, 245, 246 }
--
-- This uses tail recursion so hopefully lua is smart enough not to blow the stack
function arrayCombine(tableArray)
-- Define the base cases
if (tableArray == nil) then
return nil
elseif (#tableArray == 0) then
return {}
elseif (#tableArray == 1) then
return tableArray[1]
elseif (#tableArray == 2) then
return arrayCombine2(tableArray[1], tableArray[2])
end -- if
-- We have more than 2 tables in the input parameter. We want to pick off the *last*
-- two arrays, merge them, and then recursively call this function again so that we
-- can work our way up to the front.
local lastArray = table.remove(tableArray, #tableArray)
local nextToLastArray = table.remove(tableArray, #tableArray)
local mergedArray = arrayCombine2(nextToLastArray, lastArray)
table.insert(tableArray, mergedArray)
return arrayCombine(tableArray)
end -- arrayCombine
function arrayCombine2(array1, array2)
local mergedArray = {}
for _, elementA in ipairs(array1) do
for _, elementB in ipairs(array2) do
table.insert(mergedArray, elementA .. elementB)
end -- for
end -- for
return mergedArray
end -- arrayCombine2
-- You can set it up this way:
combinedArray = {}
table.insert(combinedArray, {"A", "B", "C"})
table.insert(combinedArray, {"D", "E", "F"})
for i,v in ipairs(arrayCombine(combinedArray)) do
print(i,v)
end
-- Or go this way, which may be somewhat cleaner:
for i,v in ipairs(arrayCombine({{"A", "B", "C"}, {"D", "E", "F"}})) do
print(i,v)
end
Either way, it produces the results you're looking for.
I've been asking questions on random numbers, and I decide the Fisher-Yates shuffle would be the best option. I make a table 't'
t = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
Now, how would I even shuffle these and be able to use them individually, for example generate the results in another table u
u = {}
For those that find this answer later, this will shuffle in place without making a new table:
local function ShuffleInPlace(t)
for i = #t, 2, -1 do
local j = math.random(i)
t[i], t[j] = t[j], t[i]
end
end
And this one that returns a shuffled table without touching the original (unlike the current answer, which both shuffles in-place and returns a copy):
local function Shuffle(t)
local s = {}
for i = 1, #t do s[i] = t[i] end
for i = #t, 2, -1 do
local j = math.random(i)
s[i], s[j] = s[j], s[i]
end
return s
end
Usage:
local t = {"a", "b", "c", "d", "e", "f"}
print(table.concat(t)) --> abcdef
local s = Shuffle(t)
print(table.concat(t)) --> abcdef (unchanged)
print(table.concat(s)) --> fbcade (shuffled)
ShuffleInPlace(t)
print(table.concat(t)) --> dcbfea (shuffled)
And a quick sanity check that they're uniform:
local t = {"a", "b", "c"}
local results = {abc = 0,acb = 0,bac = 0,bca = 0,cab = 0,cba = 0}
for i = 1, 10000000 do
ShuffleInPlace(t)
local r = table.concat(t)
results[r] = results[r] + 1
end
for k, v in pairs(results) do print(k, v) end
--[[
cba 1667473
cab 1666235
bca 1665672
bac 1666782
acb 1666447
abc 1667391
--]]
NOTE: Check the other answer https://stackoverflow.com/a/68486276/1190388 which fixes an issue in the code snippet below as well as providing other alternatives
If you do not have holes in your table:
math.randomseed(os.time()) -- so that the results are always different
function FYShuffle( tInput )
local tReturn = {}
for i = #tInput, 1, -1 do
local j = math.random(i)
tInput[i], tInput[j] = tInput[j], tInput[i]
table.insert(tReturn, tInput[i])
end
return tReturn
end
I'm struggling with this problem:
Given 2 strings:
s1 = '/foo/:bar/oof/:rab'
s2 = '/foo/lua/oof/rocks'
I would like to produce the following information:
If they match (these two above should match, s2 follows a pattern described in s1).
A table holding the values of s2 in with the corresponding name in s1. In this case we would have: { bar = "lua", rab = "rocks" }
I think this algorithm solves it, but I can't figure how to implement it (probably with gmatch):
store the placeholders : indexes as KEYS of a table, and the respective VALUES being the name of these placeholders.
Example with s1:
local aux1 = { "6" = "bar", "15" = "rab" }
With the keys of aux1 fetched as indexes, extract the values of s2
into another table:
local aux2 = {"6" = "lua", "15" = "rocks"}
Finally merge them two into one table (this one is easy :P)
{ bar = "lua", rab = "rocks" }
Something like this maybe:
function comp(a,b)
local t = {}
local i, len_a = 0
for w in (a..'/'):gmatch('(.-)/') do
i = i + 1
if w:sub(1,1) == ':' then
t[ -i ] = w:sub(2)
else
t[ i ] = w
end
end
len_a = i
i = 0
local ans = {}
for w in (b..'/'):gmatch('(.-)/') do
i = i + 1
if t[ i ] and t[ i ] ~= w then
return {}
elseif t[ -i ] then
ans[ t[ -i ] ] = w
end
end
if len_a ~= i then return {} end
return ans
end
s1 = '/foo/:bar/oof/:rab'
s2 = '/foo/lua/oof/rocks'
for k,v in pairs(comp(s1,s2)) do print(k,v) end
Another solution could be:
s1 = '/foo/:bar/oof/:rab'
s2 = '/foo/lua/oof/rocks'
pattern = "/([^/]+)"
function getStrngTable(_strng,_pattern)
local t = {}
for val in string.gmatch(_strng,_pattern) do
table.insert(t,val)
end
return t
end
local r = {}
t1 = getStrngTable(s1,pattern)
t2 = getStrngTable(s2,pattern)
for k = 1,#t1 do
if (t1[k] == t2[k]) then
r[t1[k + 1]:match(":(.+)")] = t2[k + 1]
end
end
The Table r will have the required result
The solution below, which is some what cleaner, will also give the same result:
s1 = '/foo/:bar/oof/:rab'
s2 = '/foo/lua/oof/rocks'
pattern = "/:?([^/]+)"
function getStrng(_strng,_pattern)
local t = {}
for val in string.gmatch(_strng,_pattern) do
table.insert(t,val)
end
return t
end
local r = {}
t1 = getStrng(s1,pattern)
t2 = getStrng(s2,pattern)
for k = 1,#t1 do
if (t1[k] == t2[k]) then
r[t1[k + 1]] = t2[k + 1]
end
end
Trying to allow a concatenated table to be referenced as such:
local group = table.concat(arguments, ",", 1)
where arguments = {"1,1,1"}
Currently, doing group[2] gives me the comma. How do I avoid that while still allowing for two-digit numbers?
(snippet of what I'm trying to use it for)
for i = 1, #group do
target:SetGroup(i, tonumber(group[i]))
end
Maybe you want something like
local i = 1
for v in string.gmatch(s, "(%w+),*") do
group[i] = v
i = i + 1
end
Revised version in response to comment, avoiding the table altogether:
local i = 1
for v in string.gmatch(s, "(%w+),*") do
target:SetGroup(i, tonumber(v))
i = i + 1
end
split function (you have to add it to code)
split = function(str, delim)
if not delim then
delim = " "
end
-- Eliminate bad cases...
if string.find(str, delim) == nil then
return { str }
end
local result = {}
local pat = "(.-)" .. delim .. "()"
local nb = 0
local lastPos
for part, pos in string.gfind(str, pat) do
nb = nb + 1
result[nb] = part
lastPos = pos
end
-- Handle the last field
result[nb + 1] = string.sub(str, lastPos)
return result
end
so
local arguments = {"1,1,1"};
local group = split(arguments[1], ",");
for i = 1, #group do
target:SetGroup(i, tonumber(group[i]))
end
also note that
local arguments = {"1,1,1"};
local group = split(arguments[1], ",");
local group_count = #group;
for i = 1, group_count do
target:SetGroup(i, tonumber(group[i]))
end
is faster code ;)