I have an array of comma delimited string. I turn that into an array of arrays by splitting out the csvs. It looks okay in my loop (from the output), giving me an array of strings. However, after I add the array of strings to another array, it seems to get messed up.
Output at the end shows a character from a string, not an actual string.
foreach($n in $Names)
{
$obj = ([string]$n.value).Split(",")
"0: " + $obj[0]
"1: " + $obj[1]
#$obj.GetTYpe()
$arrInfo+= $obj
}
$arrinfo[5][0]
$arrinfo[5][1]
$a = $arrinfo[5]
$a[0]
$a[1]
Output looks something like:
0: Item 0 string
1: Item 1 string
....
I
t
I
t
What is going wrong? Why is my second array (arrInfo) seem to have just strings instead of an array of strings?
After looking around a little more, I changed the line to read: $arrinfo += , $obj and it works as expected. I don't fully understand why.
Related
how can I extract a few words separated by symbols in a string so that nothing is extracted if the symbols change?
for example I wrote this code:
function split(str)
result = {};
for match in string.gmatch(str, "[^%<%|:%,%FS:%>,%s]+" ) do
table.insert(result, match);
end
return result
end
--------------------------Example--------------------------------------------
str = "<busy|MPos:-750.222,900.853,1450.808|FS:2,10>"
my_status={}
status=split(str)
for key, value in pairs(status) do
table.insert(my_status,value)
end
print(my_status[1]) --
print(my_status[2]) --
print(my_status[3]) --
print(my_status[4]) --
print(my_status[5]) --
print(my_status[6]) --
print(my_status[7]) --
output :
busy
MPos
-750.222
900.853
1450.808
2
10
This code works fine, but if the characters and text in the str string change, the extraction is still done, which I do not want to be.
If the string change to
str = "Hello stack overFlow"
Output:
Hello
stack
over
low
nil
nil
nil
In other words, I only want to extract if the string is in this format: "<busy|MPos:-750.222,900.853,1450.808|FS:2,10>"
In lua patterns, you can use captures, which are perfect for things like this. I use something like the following:
--------------------------Example--------------------------------------------
str = "<busy|MPos:-750.222,900.853,1450.808|FS:2,10>"
local status, mpos1, mpos2, mpos3, fs1, fs2 = string.match(str, "%<(%w+)%|MPos:(%--%d+%.%d+),(%--%d+%.%d+),(%--%d+%.%d+)%|FS:(%d+),(%d+)%>")
print(status, mpos1, mpos2, mpos3, fs1, fs2)
I use string.match, not string.gmatch here, because we don't have an arbitrary number of entries (if that is the case, you have to have a different approach). Let's break down the pattern: All captures are surrounded by parantheses () and get returned, so there are as many return values as captures. The individual captures are:
the status flag (or whatever that is): busy is a simple word, so we can use the %w character class (alphanumeric characters, maybe %a, only letters would also do). Then apply the + operator (you already know that one). The + is within the capture
the three numbers for the MPos entry each get (%--%d+%.%d+), which looks weird at first. I use % in front of any non-alphanumeric character, since it turns all magic characters (such as + into normal ones). - is a magic character, so it is required here to match a literal -, but lua allows to put that in front of any non-alphanumerical character, which I do. So the minus is optional, so the capture starts with %-- which is one or zero repetitions (- operator) of a literal - (%-). Then I just match two integers separated by a dot (%d is a digit, %. matches a literal dot). We do this three times, separated by a comma (which I don't escape since I'm sure it is not a magical character).
the last entry (FS) works practically the same as the MPos entry
all entries are separated by |, which I simply match with %|
So putting it together:
start of string: %<
status field: (%w+)
separator: %|
MPos (three numbers): MPos:(%--%d+%.%d+),(%--%d+%.%d+),(%--%d+%.%d+)
separator: %|
FS entry (two integers): FS:(%d+),(%d+)
end of string: %>
With this approach you have the data in local variables with sensible names, which you can then put into a table (for example).
If the match failes (for instance, when you use "Hello stack overFlow"), nil` is returned, which can simply be checked for (you could check any of the local variables, but it is common to check the first one.
I'm trying to phrase a string for a hobby project and I'm self taught from code snips from this site and having a hard time working out this problem. I hope you guys can help.
I have a large string, containing many lines, and each line has a certain format.
I can get each line in the string using this code...
for line in string.gmatch(deckData,'[^\r\n]+') do
print(line) end
Each line looks something like this...
3x Rivendell Minstrel (The Hunt for Gollum)
What I am trying to do is make a table that looks something like this for the above line.
table = {}
table['The Hunt for Gollum'].card = 'Rivendell Minstrel'
table['The Hunt for Gollum'].count = 3
So my thinking was to extract everything inside the parentheses, then extract the numeric vale. Then delete the first 4 chars in the line, as it will always be '1x ', '2x ' or '3x '
I have tried a bunch of things.. like this...
word=str:match("%((%a+)%)")
but it errors if there are spaces...
my test code looks like this at the moment...
line = '3x Rivendell Minstrel (The Hunt for Gollum)'
num = line:gsub('%D+', '')
print(num) -- Prints "3"
card2Fetch = string.sub(line, 5)
print(card2Fetch) -- Prints "Rivendell Minstrel (The Hunt for Gollum)"
key = string.gsub(card2Fetch, "%s+", "") -- Remove all Spaces
key=key:match("%((%a+)%)") -- Fetch between ()s
print(key) -- Prints "TheHuntforGollum"
Any ideas how to get the "The Hunt for Gollum" text out of there including the spaces?
Try a single pattern capturing all fields:
x,y,z=line:match("(%d+)x%s+(.-)%s+%((.*)%)")
t = {}
t[z] = {}
t[z].card = y
t[z].count = x
The pattern reads: capture a run of digits before x, skip whitespace, capture everything until whitespace followed by open parenthesis, and finally capture everything until a close parenthesis.
I am using torch.CmdLine() to parse command line arguments in Torch. I need to pass an array of elements for one of the variables. I am not aware of any mechanisms for passing an array of elements for a variable. So I am treating that variable as a string and passing the array of elements separated by space and enclosed within double quotes from the command line.
The code for doing this looks as follows:
cmd = torch.CmdLine()
cmd:text('Training')
cmd:text()
cmd:option('-cuda_device',"1 2 3")
params = cmd:parse(arg or {})
--parse the string to extract array of numbers
for i=1,string.len(params.cuda_device) do
if params.cuda_device[i] ~= ' ' then
-- some code here
end
end
Here since Lua string indexing is not provided by default, I had to override __index to enable indexing of string as follows,
getmetatable('').__index = function(str,i) return string.sub(str,i,i) end
This works for parsing the string to an array of numbers.
However, overriding __index breaks the code somewhere else, throwing the following error:
qlua: /home/torch/install/share/lua/5.1/torch/init.lua:173: bad argument #2 to '__index' (number expected, got string)
I can do some workarounds to fix this (instead of overriding __index use string.sub(str,i,i) directly) but I would like to know your suggestions in passing an array of elements using torch.CmdLine() in an elegant way--if applicable.
Thanks in Advance.
You can pass the list as a sequence of words separated by spaces as you have done, and after cmd:parse you can explode the string into an array using:
params = cmd:parse()
local tmptab = {}
for word in params.cuda_device:gmatch("%w+") do
tmptab[#tmptab +1] = word
end
params.cuda_device = tmptab
for i,v in pairs(params.cuda_device) do
-- some code here
end
That will explode the string parsed by cmd:parse() into an table with each word on it's on index, and there would be no need to delve into string metamethods...
Also, you can avoid the error doing this:
getmetatable('').__index = function(str,i)
if(type(i) == "number") then
return string.sub(str,i,i)
else
return ""
end
end
It is odd that you have tried to index a string using another string, however...
I have read a multiline file and converted it to a list with the following code:
Lines = string:tokens(erlang:binary_to_list(Binary), "\n"),
I converted it to a string to do some work on it:
Flat = string:join(Lines, "\r\n"),
I finished working on the string and now I need to convert it back to a multiline list, I tried to repeat the first snippet shown above but that never worked, I tried string:join and that didnt work.. how do i convert it back to a list just like it used to be (although now modified)?
Well that depends on the modifications you made on the flattened string.
string:tokens/2 will always explode a string using the separator you provide. So as long as your transformation preserves a specific string as separator between the individual substrings there should be no problem.
However, if you do something more elaborate and destructive in your transformation then the only way is to iterate on the string manually and construct the individual substrings.
Your first snippet above contains a call to erlang:binary_to_list/1 which first converts a binary to a string (list) which you then split with the call to string:tokens/2 which then join together with string:join/2. The result of doing the tokens then join as you have written it seems to be to convert it from a string containing lines separated by \n into one containing lines separated by \r\n. N.B. that this is a flat list of characters.
Is this what you intended?
What you should do now depends on what you mean by "I need to convert it back to a multiline list". Do you mean everything in a single list of characters (string), or in a nested list of lines where each line is a list of characters (string). I.e. if you ended up with
"here is line 1\r\nhere is line 2\r\nhere is line 3\r\n"
this already is a multiline line list, or do you mean
["here is line 1","here is line 2","here is line 3"]
Note that each "string" is itself a list of characters. What do you intend to do with it afterwards?
You have your terms confused. A string in any language is a sequence of integer values corresponding to a human-readable characters. Whether the representation of the value is a binary or a list does not matter, both are technically strings because of the data they contain.
That being said, you converted a binary string to a list string in your first set of instructions. To convert a list into a binary, you can call erlang:list_to_binary/1, or erlang:iolist_to_binary/1 if your list is not flat. For instance:
BinString = <<"this\nis\na\nstring">>.
ListString = "this\nis\na\nstring" = binary_to_list(BinString).
Words = ["this", "is", "a", "string"] = string:tokens(ListString, "\n").
<<"thisisastring">> = iolist_to_binary(Words).
Rejoined = "this\r\nis\r\na\r\nstring" = string:join(Words, "\r\n").
BinAgain = <<"this\r\nis\r\na\r\nstring">> = list_to_binary(Rejoined).
For your reference, the string module always expects a flat list (e.g., "this is a string", but not ["this", "is", "a", "string"]), except for string:join, which takes a list of flat strings.
Hello
after doing the parsing with a script in Haskell I got a file with the 'appearance' of lists of strings. However when I call the file content with the function getContents or hGetContents, ie, reading the contents I get something like: String with lines (schematically what I want is: "[" aaa "," bbb "" ccc "]" -> ["aaa", "bbb" "ccc"]). I have tried with the read function but without results. I need to work with these lists of strings to concatenating them all in a single list.
I'm using the lines function, but I think it only 'works' one line at a time, doesn't it?
What I need is a function that verify if an element of a line is repeted on other line. If I could have a list of a list of strings it could be easier (but what I have is a line of a string that looks like a list of strings)
Regards
Thanks.
I have tried with the read function but without results
Just tested, and it works fine:
Prelude> read "[\"aaa\",\"bbb\",\"ccc\"]" :: [String]
["aaa","bbb","ccc"]
Note that you need to give the return type explicitly, since it can't be determined from the type of the argument.
I think the function you are looking for is the lines function from Data.List (reexported by the Prelude) that breaks up a multi-line string into a list of strings.
in my understanding, what you can do is
create a function that receives a list of lists, each list is a line of the entire string, of the argument passed in, and checks if a element of a line occurs in other line.
then, this function passes the entire string, separated by lines using [lines][1].