How to detect if a field contains a character in Lua - lua

I'm trying to modify an existing lua script that cleans up subtitle data in Aegisub.
I want to add the ability to delete lines that contain the symbol "♪"
Here is the code I want to modify:
-- delete commented or empty lines
function noemptycom(subs,sel)
progress("Deleting commented/empty lines")
noecom_sel={}
for s=#sel,1,-1 do
line=subs[sel[s]]
if line.comment or line.text=="" then
for z,i in ipairs(noecom_sel) do noecom_sel[z]=i-1 end
subs.delete(sel[s])
else
table.insert(noecom_sel,sel[s])
end
end
return noecom_sel
end
I really have no idea what I'm doing here, but I know a little SQL and LUA apparently uses the IN keyword as well, so I tried modifying the IF line to this
if line.text in (♪) then
Needless to say, it didn't work. Is there a simple way to do this in LUA? I've seen some threads about the string.match() & string.find() functions, but I wouldn't know where to start trying to put that code together. What's the easiest way for someone with zero knowledge of Lua?

in is only used in the generic for loop. Your if line.text in (♪) then is no valid Lua syntax.
Something like
if line.comment or line.text == "" or line.text:find("\u{266A}") then
Should work.

In Lua every string have the string functions as methods attached.
So use gsub() on your string variable in loop like...
('Text with ♪ sign in text'):gsub('(♪)','note')
...thats replace the sign and output is...
Text with note sign in text
...instead of replacing it with 'note' an empty '' deletes it.
gsub() is returning 2 values.
First: The string with or without changes
Second: A number that tells how often the pattern matches
So second return value can be used for conditions or success.
( 0 stands for "pattern not found" )
So lets check above with...
local str,rc=('Text with strange ♪ sign in text'):gsub('(♪)','notation')
if rc~=0 then
print('Replaced ',rc,'times, changed to: ',str)
end
-- output
-- Replaced 1 times, changed to: Text with strange notation sign in text
And finally only detect, no change made...
local str,rc=('Text with strange ♪ sign in text'):gsub('(♪)','%1')
if rc~=0 then
print('Found ',rc,'times, Text is: ',str)
end
-- output is...
-- Found 1 times, Text is: Text with strange ♪ sign in text
The %1 holds what '(♪)' found.
So ♪ is replaced with ♪.
And only rc is used as a condition for further handling.

Related

Check if String Contains an Emoji in Ruby

In ruby, here is how you can check for a substring in a string:
str = "hello world"
str.include?("lo")
=> true
When I am attempting to save an emoji in a text column in a rails application (the text column within a mysql database is utf8), it comes back with this error:
Incorrect string value: \xF0\x9F\x99\x82
For my situation in a rails application, it suffices to see if an emoji is present in the submitted text. If an emoji is present: raise a validation error. Example:
class MyModel < ApplicationRecord
validate :cannot_contain_emojis
private
def cannot_contain_emojis
if my_column.include?("/\xF0")
errors.add(:my_column, 'Cannot include emojis")
end
end
end
Note: The reason I am checking for \xF0 is because according to this site, it appears that all, or most, emoji's begin with this signature.
This however does not work. It continues to return false even when it is true. I'm pretty sure the issue is that my include statement doesn't work because the emoji is not converted to bytes for the comparison.
Question
How can I make a validation to check that an emoji is not passed in?
Example bytes for a smiley face in UTF8: \xF0\x9F\x99\x82
You can use the Emoji Unicode property to test for Emoji using a Regexp, something like this:
def cannot_contain_emojis
if /\p{Emoji}/ =~ my_column
errors.add(:my_column, 'Cannot include emojis')
end
end
Unicode® Technical Standard #51 "UNICODE EMOJI" contains a more sophisticated regex:
\p{RI} \p{RI}
| \p{Emoji}
( \p{EMod}
| \x{FE0F} \x{20E3}?
| [\x{E0020}-\x{E007E}]+ \x{E007F} )?
(\x{200D} \p{Emoji}
( \p{EMod}
| \x{FE0F} \x{20E3}?
| [\x{E0020}-\x{E007E}]+ \x{E007F} )?
)*
[Note: some of those properties are not implemented in Onigmo / Ruby.]
However, checking for Emojis probably not going to be enough. It is pretty clear that your text processing is somehow broken at some point. And if it is broken by an Emoji, then there is a chance it will also be broken by my name, or the name of Ruby's creator 松本 行弘, or by the completely normal English word “naïve”.
Instead of playing a game of whack-a-mole trying to detect every Emoji, mathematical symbol, Arabic letter, typographically correct punctuation mark, etc., it would be much better simply the fix the text processing.
I found Jörg's solution was only working when passing in the string itself and not a variable. Not sure why that is.
/\p{Emoji}/ =~ "🎃"
=> 0
value = "1f383"
=> "1f383"
/\p{Emoji}/ =~ value
=> 0
/\p{Emoji}/ =~ "hello"
=> nil
Regardless I'd recommend using the unicode-emoji gem, as its approach is comprehensive. Its source code and documentation can be found on GitHub.

0 Checking if TextBox.Text contains the string in the table. But it doesn't work? Lua

I am making a script inside TextButton script that will check if the TextBox contains any of the word or string inside the table.
text = script.Parent.Parent:WaitForChild('TextBox')
label = script.Parent.Parent:WaitForChild('TextLabel')
a = {'test1','test2','test3'}
script.Parent.MouseButton1Click:connect(function()
if string.match(text.Text, a) then
label.Text = "The word "..text.Text.." was found in the table."
else
label.Text = "The word "..text.Text.." was not found in the table."
end
end)
But it gives an error string expected, got table. from line 7 which is refering to the line if string.match....
Is there any way to get all text in the table?
What's the right way to do it?
Oh boy, there's a lot to say about this.
The error message
Yes.
No, seriously, the answer is yes. The error message is exactly right. a is a table value; you can clearly see that on the third line of code. string.match needs a string as its second argument, so it obviously crashes.
Simple solution
use a for loop and check for each string in a separately.
found = false
for index, entry in ipairs(a) do
if entry == text.Text then
found = true
end
end
if found then
... -- the rest of your code
The better* solution
In Lua, if we want to know if a single element is in a set, we usually take advantage of the fact that tables are implemented as hashmaps, meaning they are very fast when looking up keys.
For that to work, one first needs to change the way the table looks:
a = {["test1"] = true, ["test2"] = true, ["test3"] = true}
Then we can just index a with a string to find out if it is contained int eh set.
if a[text.Text] then ...
* In practice this is just as good as the first solution as long as you only have a few elements in your table. It only becomes relevant when you have a few hundred entries or your code needs to run absolutely as fast as possible.

Confirming existence of a string in an xml table Lua

Good afternoon everyone,
My problem is that I have 2 XML lists
<List1> <Agency>String</Agency> </List1>
and
<List2><Agency2>String</Agency2><List2>.
In Lua I need to create a program which is parsing this list and when the user inputs a matching string from List 1 or List 2, the program needs to actually confirm to the user if the string belongs to either L1 or L2 or if the string is inexistent. I'm new to Lua and to programming generally speaking and I would be very grateful for you answers. I have LuaExpat as a plugin but I can't seem to be able to actually read from file, I can only do some beginner tricks if the xml list is written in the code. At a later time this small program will be fed by an RSS.
require("lxp")
local stuff = {}
xmldata="<Top><A/> <B a='1'/> <B a='2'/><B a='3'/><C a='3'/></Top>"
function doFunc(parser, name, attr)
if not (name == 'B') then return end
stuff[#stuff+1]= attr
end
local xml = lxp.new{StartElement = doFunc}
xml:parse(xmldata)
xml:close()
print(stuff[3].a)
This code is a tutorial over the web that works, everything is just fine it prints nr. 3. Now I want to know how to do that from an actual file, as if I input io.read:(file, "r" or "rb" ) under xmldata variable and run the same thing it returns either empty space or nil.

Adding labels to my programming language

Actually I am writting a programming language in Lua. It was quite fun. I've wrote a bit of standard library (stack op and simple io). Then I've thought about labels. It would look like in assembly. While and for loop aren't funny in any bit so programming in that language can be quite challenging. Here are some requirements for this system:
Label stack (or array, dictionary) must be accessible from global context.
Jump instruction handler will be in separate file.
This is how my label-handling function look like:
function handleLabel(name,currentLine)
end
I have no idea how to implement this kind of magic. First I've thought about that:
LabelLineIDS = {}
Labels = {}
Labelamount = 1;
function handleLabel(name,currentLine)
LabelLineIDS[Labelamount]=currentline
Labels[Labelamount]=name
Labelamount=Labelamount+1
end
-- In file "jump.lua":
local function has_value (tab, val)
for index, value in ipairs(tab) do
if value == val then
return index
end
end
print ("Error: Label not defined.") -- Bail out.
os.exit(1)
end
local function _onlabel()
local labelName = globalparams --Globalparams variable contain parameters to each function, at the moment
--this will contain label name. It _can_ be nil.
return LabelLineIDS[has_value(Labels, labelName)]
end
CurrLine = _onlabel() --Currline - current line that get's parsed.
--1 command per one line.
But I'm unsure is this well written or even work. Can you give me idea how to parse labels in my programming language (and write jump functions)? Or if my code is pretty ok at the moment, can you help me to improve it?
Using line counter in my parser I've decided to implement gotos like we can see in BASIC. Thanks everyone for help.

changing a variable using gets.chomp()

im trying to write to a file using this code:
puts "-------------------- TEXT-EDITOR --------------------"
def tor(old_text)
old_text = gets.chomp #
end
$epic=""
def torr(input)
tore= $epic += input + ", "
File.open("tor.txt", "w") do |write|
write.puts tore
end
end
loop do
output = tor(output)
torr(output)
end
i have read the ultimate guide to ruby programming
and it says if i want to make a new line using in the file im writing to using File.open
i must use "line one", "line two
how can i make this happend using gets.chomp()? try my code and you will see what i mean
thank you.
The gets method will bring in any amount of text but it will terminate when you hit 'Enter' (or once the STDIN receives \n). This input record separator is stored in the global variable $/. If you change the input separator in your script, the gets method will actually trade the 'Enter' key for whatever you changed the global variable to.
$/ = 'EOF' # Or any other string
lines = gets.chomp
> This is
> multilined
> textEOF
lines #=> 'This is\nmultilined\ntext'
Enter whatever you want and then type 'EOF' at the end. Once it 'sees' EOF, it'll terminate the gets method. The chomp method will actually strip off the string 'EOF' from the end.
Then write this to your text file and the \n will translate into new lines.
File.open('newlines.txt', 'w') {|f| f.puts lines}
newlines.txt:
This is
multilined
text
If you dont use .chomp() the \n character will be added whenever you write a new line, if you save this to the file it also will have a new line. .chomp() removes those escape characters from the end of the input.
If this doesnt answer your question, i am sorry i dont understand it.

Resources