I have a search replace script which works to replace strings. It already has options to do case insensitive searches and "escaped" matches (eg allows searching for % ( etc in the search.
How ever I have now been asked to match whole words only, I have tried adding %s to each end, but that does not match words at the end of a string and I can't then work out how to trap for the white-space items found to leave them intact during the replace.
Do I need to redo the script using string.find and add logic for the word checking or this possible with patterns.
The two functions I use for case insensitive and escaped items are as follows both return the pattern to search for.
-- Build Pattern from String for case insensitive search
function nocase (s)
s = string.gsub(s, "%a", function (c)
return string.format("[%s%s]", string.lower(c),
string.upper(c))
end)
return s
end
function strPlainText(strText)
-- Prefix every non-alphanumeric character (%W) with a % escape character, where %% is the % escape, and %1 is original character
return strText:gsub("(%W)","%%%1")
end
I have a way of doing what I want now, but it's inelegant. Is there a better way?
local strToString = ''
local strSearchFor = strSearchi
local strReplaceWith = strReplace
bSkip = false
if fhGetDataClass(ptr) == 'longtext' then
strBoxType = 'm'
end
if pWhole == 1 then
strSearchFor = '(%s+)('..strSearchi..')(%s+)'
strReplaceWith = '%1'..strReplace..'%3'
end
local strToString = string.gsub(strFromString,strSearchFor,strReplaceWith)
if pWhole == 1 then
-- Special Case search for last word and first word
local strSearchFor3 = '(%s+)('..strSearchi..')$'
local strReplaceWith3 = '%1'..strReplace
strToString = string.gsub(strToString,strSearchFor3,strReplaceWith3)
local strSearchFor3 = '^('..strSearchi..')(%s+)'
local strReplaceWith3 = strReplace..'%2'
strToString = string.gsub(strToString,strSearchFor3,strReplaceWith3)
end
have a way of doing what I want now, but it's inelegant. Is there a better way?
There is an undocumented feature of Lua's pattern matching library called the Frontier Pattern, which will let you write something like this:
function replacetext(source, find, replace, wholeword)
if wholeword then
find = '%f[%a]'..find..'%f[%A]'
end
return (source:gsub(find,replace))
end
local source = 'test testing this test of testicular footest testimation test'
local find = 'test'
local replace = 'XXX'
print(replacetext(source, find, replace, false)) --> XXX XXXing this XXX of XXXicular fooXXX XXXimation XXX
print(replacetext(source, find, replace, true )) --> XXX testing this XXX of testicular footest testimation XXX
do you mean if you pass nocase() foo, you want [fooFOO] instead of [fF][oO][oO]? if so, you could try this?
function nocase (s)
s = string.gsub(s, "(%a+)", function (c)
return string.format("[%s%s]", string.lower(c),
string.upper(c))
end)
return s
end
and if you want an easy way to split a sentence into words, you can use this:
function split(strText)
local words = {}
string.gsub(strText, "(%a+)", function(w)
table.insert(words, w)
end)
return words
end
once you've gotten the words split, it's pretty easy to iterate over the words in the table and do a full comparison against each word.
Related
I have a file database. Inside that file I have something like:
DB_A = ...
DB_B = ...
.
.
.
DB_N = ...
I would like to parse the data and group them in lua code like this:
data={}
-- the result after parsing a file
data={
["DB_A"] = {...},
["DB_B"] = {...},
.
.
.
["DB_N"] = {...}
}
In other words, is it possible to create a table inside a table dynamically and assign the key to each table without previously knowing what will be the names of the key (that is something I can figure out after parsing the data from a database).
(Just as a note, I am using Lua 5.3.5; also, I apologize that my code resembles C more than Lua!)
Iterating through your input file line-by-line--which can be done with the Lua FILE*'s lines method--you can use string.match to grab the information you are looking for from each line.
#!/usr/bin/lua
local PATTERN = "(%S+)%s?=%s?(%S+)"
local function eprintf(fmt, ...)
io.stderr:write(string.format(fmt, ...))
return
end
local function printf(fmt, ...)
io.stdout:write(string.format(fmt, ...))
return
end
local function make_table_from_file(filename)
local input = assert(io.open(filename, "r"))
local data = {}
for line in input:lines() do
local key, value = string.match(line, PATTERN)
data[key] = value
end
return data
end
local function main(argc, argv)
if (argc < 1) then
eprintf("Filename expected from command line\n")
os.exit(1)
end
local data = make_table_from_file(argv[1])
for k, v in pairs(data) do
printf("data[%s] = %s\n", k, data[k])
end
return 0
end
main(#arg, arg)
The variable declared at the top of the file, PATTERN, is your capture pattern to be used by string.match. If you are unfamiliar with how Lua's pattern matching works, this pattern looks for a series of non-space characters with zero or one spaces to its right, an equal sign, another space, and then another series of non-space characters. The two series of non-space characters are the two matches--key and value--returned by string.match in the function make_table_from_file.
The functions eprintf and printf are my Lua versions of C-style formatted output functions. The former writes to standard error, io.stderr in Lua; and the latter writes to standard output, io.stdout in Lua.
In your question, you give a sample of what your expected output is. Within your table data, you want it to contain keys that correspond to tables as values. Based on the sample input text you provided, I assume the data contained within these tables are whatever comes to the right of the equal signs in the input file--which you represent with .... As I do not know what exactly those ...s represent, I cannot give you a solid example for how to separate that right-hand data into a table. Depending on what you are looking to do, you could take the second variable returned by string.match, which I called value, and further separate it using Lua's string pattern matching. It could look something like this:
...
local function make_table_from_value(val)
// Split `val` into distinct elements to form a table with `some_pattern`
return {string.match(val, some_pattern)}
end
local function make_table_from_file(filename)
local input = assert(io.open(filename, "r"))
local data = {}
for line in input:lines() do
local key, value = string.match(line, PATTERN)
data[key] = make_table_from_value(value)
end
return data
end
...
In make_table_from_value, string.match will return some number of elements, based on whatever string pattern you provide as its second argument, which you can then use to create a table by enclosing the function call in curly braces. It will be a table that uses numerical indices as keys--rather than strings or some other data type--starting from 1.
I see several posts about making a string in to a lua table, but my problem is a little different [I think] because there is an additional dimension to the table.
I have a table of tables saved as a file [i have no issue reading the file to a string].
let's say we start from this point:
local tot = "{{1,2,3}, {4,5,6}}"
When I try the answers from other users I end up with:
local OneDtable = {"{1,2,3}, {4,5,6}"}
This is not what i want.
how can i properly create a table, that contains those tables as entries?
Desired result:
TwoDtable = {{1,2,3}, {4,5,6}}
Thanks in advance
You can use the load function to read the content of your string as Lua code.
local myArray = "{{1,2,3}, {4,5,6}}"
local convert = "myTable = " .. myArray
local convertFunction = load(convert)
convertFunction()
print(myTable[1][1])
Now, myTable has the values in a 2-dimensional array.
For a quick solution I suggest going with the load hack, but be aware that this only works if your code happens to be formatted as a Lua table already. Otherwise, you'd have to parse the string yourself.
For example, you could try using lpeg to build a recursive parser. I built something very similar a while ago:
local lpeg = require 'lpeg'
local name = lpeg.R('az')^1 / '\0'
local space = lpeg.S('\t ')^1
local function compile_tuple(...)
return string.char(select('#', ...)) .. table.concat{...}
end
local expression = lpeg.P {
'e';
e = name + lpeg.V 't';
t = '(' * ((lpeg.V 'e' * ',' * space)^0 * lpeg.V 'e') / compile_tuple * ')';
}
local compiled = expression:match '(foo, (a, b), bar)'
print(compiled:byte(1, -1))
Its purpose is to parse things in quotes like the example string (foo, (a, b), bar) and turn it into a binary string describing the structure; most of that happens in the compile_tuple function though, so it should be easy to modify it to do what you want.
What you'd have to adapt:
change name for number (and change the pattern accordingly to lpeg.R('09')^1, without the / '\0')
change the compile_tuple function to a build_table function (local function build_tanle(...) return {...} end should do the trick)
Try it out and see if something else needs to be changed; I might have missed something.
You can read the lpeg manual here if you're curious about how this stuff works.
I need to find a way to see how many times an entry is listed in a table.
I have tried looking at other code for help, and looking at examples online none of them help
local pattern = "(.+)%s?-%s?(.+)"
local table = {"Cald_fan:1", "SomePerson:2", "Cald_fan:3","anotherPerson:4"}
for i,v in pairs(table) do
local UserId, t = string.match(v, pattern)
for i,v in next,UserId do
--I have tried something like this
end
end
it is suppose to say Cald_fan was listed 2 times
Something like this should work:
local pattern = "(.+)%s*:%s*(%d+)"
local tbl = {"Cald_fan:1", "SomePerson:2", "Cald_fan:3","anotherPerson:4"}
local counts = {}
for i,v in pairs(tbl) do
local UserId, t = string.match(v, pattern)
counts[UserId] = 1 + (counts[UserId] or 0)
end
print(counts['Cald_fan']) -- 2
I renamed table to tbl (as using table variable makes the table.* functions not available) and fix the pattern (you had unescaped '-' in it, while your strings had ':').
If the format of your table entries is consistent, you can simply split the strings apart and use the components as keys in a map of counters.
It looks like your table entries are formatted as "[player_name]:[index]", but it doesn't look like you care about the index. But, if the ":" will be in every table entry, you can write a pretty reliable search pattern. You could try something like this :
-- use a list of entries with the format <player_name>:<some_number>
local entries = {"Cald_fan:1", "SomePerson:2", "Cald_fan:3","anotherPerson:4"}
local foundPlayerCount = {}
-- iterate over the list of entries
for i,v in ipairs(entries) do
-- parse out the player name and a number using the pattern :
-- (.+) = capture any number of characters
-- : = match the colon character
-- (%d+)= capture any number of numbers
local playerName, playerIndex = string.match(v, '(.+):(%d+)')
-- use the playerName as a key to count how many times it appears
if not foundPlayerCount[playerName] then
foundPlayerCount[playerName] = 0
end
foundPlayerCount[playerName] = foundPlayerCount[playerName] + 1
end
-- print out all the players
for playerName, timesAppeared in pairs(foundPlayerCount) do
print(string.format("%s was listed %d times", playerName, timesAppeared))
end
If you need to do pattern matching in the future, I highly recommend this article on lua string patterns : http://lua-users.org/wiki/PatternsTutorial
Hope this helps!
So I have a string in Lua and I want to remove all occurances ".html" text of the end of the string
local lol = ".com/url/path/stuff.html"
print(lol)
Output i want :
.com/url/path/stuff
local lol2 = ".com/url/path/stuff.html.html"
print(lol2)
Output i want :
.com/url/path/stuff
First, you could define a function like this:
function removeHtmlExtensions(s)
return s:gsub("%.html", "")
end
Then:
local lol = ".com/url/path/stuff.html"
local lol2 = ".com/url/path/stuff.html.html"
local path1 = removeHtmlExtensions(lol)
local path2 = removeHtmlExtensions(lol2)
print(path1) -- .com/url/path/stuff
print(path2) -- .com/url/path/stuff
There is a second value returned from the gsub method that indicates how many times the pattern was matched. It returns, for example, 1 with path1 and 2 with path2. (Just in case that info is useful to you):
local path2, occurrences = removeHtmlExtensions(lol2)
print(occurrences) -- 2
This can easily be done with a tail-recursive function like this:
local function foo(bar)
if bar:find('%.html$') then return foo(bar:sub(1, -5) else return bar end
end
in words:
If bar ends in '.html', remove the last 5 characters
and feed that into foo again (to remove any more occurrences)
Otherwise, return bar as it is
Benefits:
Tail recursive, so it can't overflow the stack even for very long chains '.html'
string.find is pretty fast when you anchor the search to the end of the string with $
string.sub is also rather fast compared to, for example, string.gsub (note that those two do completely different things, despite the similar name).
I need this for a game server using Lua..
I would like to be able to save all combinations of a name
into a string that can then be used with:
if exists (string)
example:
ABC_-123
aBC_-123
AbC_-123
ABc_-123
abC_-123
etc
in the game only numbers, letters and _ - . can be used as names.
(A_B-C, A-B.C, AB_8 ... etc)
I understand the logic I just don't know how to code it:D
0-Lower
1-Upper
then
000
001
etc
You can use recursive generator. The first parameter contains left part of the string generated so far, and the second parameter is the remaining right part of the original string.
function combinations(s1, s2)
if s2:len() > 0 then
local c = s2:sub(1, 1)
local l = c:lower()
local u = c:upper()
if l == u then
combinations(s1 .. c, s2:sub(2))
else
combinations(s1 .. l, s2:sub(2))
combinations(s1 .. u, s2:sub(2))
end
else
print(s1)
end
end
So the function is called in this way.
combinations("", "ABC_-123")
You only have to store intermediate results instead of printing them.
If you are interested only in the exists function then you don't need all combinations.
local stored_string = "ABC_-123"
function exists(tested_string)
return stored_string:lower() == tested_string:lower()
end
You simply compare the stored string and the tested string in case-insensitive way.
It can be easily tested:
assert(exists("abC_-123"))
assert(not exists("abd_-123"))
How to do this?
There's native function in Lua to generate all permutations of a string, but here are a few things that may prove useful.
Substrings
Probably the simplest solution, but also the least flexible. Rather than combinations, you can check if a substring exists within a given string.
if str:find(substr) then
--code
end
If this solves your problem, I highly reccomend it.
Get all permutations
A more expensive, but still a working solution. This accomplishes nearly exactly what you asked.
function GetScrambles(str, tab2)
local tab = {}
for i = 1,#str do
table.insert(tab, str:sub(i, i))
end
local tab2 = tab2 or {}
local scrambles = {}
for i = 0, Count(tab)-1 do
local permutation = ""
local a = Count(tab)
for j = 1, #tab do
tab2[j] = tab[j]
end
for j = #tab, 1, -1 do
a = a / j
b = math.floor((i/a)%j) + 1
permutation = permutation .. tab2[b]
tab2[b] = tab2[j]
end
table.insert(scrambles, permutation)
end
return scrambles
end
What you asked
Basically this would be exactly what you originally asked for. It's the same as the above code, except with every substring of the string.
function GetAllSubstrings(str)
local substrings = {}
for i = 1,#str do
for ii = i,#str do
substrings[#substrings+1]=str:sub(ii)
end
end
return substrings
end
Capitals
You'd basically have to, with every permutation, make every possible combination of capitals with it.
This shouldn't be too difficult, I'm sure you can code it :)
Are you joking?
After this you should probably be wondering. Is all of this really necessary? It seems like a bit much!
The answer to this lies in what you are doing. Do you really need all the combinations of the given characters? I don't think so. You say you need it for case insensitivity in the comments... But did you know you could simply convert it into lower/upper case? It's very simple
local str = "hELlO"
print(str:lower())
print(str:upper())
This is HOW you should store names, otherwise you should leave it case sensitive.
You decide
Now YOU pick what you're going to do. Whichever direction you pick, I wish you the best of luck!