Applescript: Condense multiple lines into one in TextWrangler - applescript

Question

I am trying to make an Applescript that condenses multiple lines down to one line.
For example
"a
b
c
d"
to
('a','b','c','d')
The string is in TextWrangler, and my script is
set AppleScript's text item delimiters to {return & linefeed, return, linefeed, character id 8233, character id 8232}
tell application "TextWrangler"
tell text window 1
set i to 2
set selection to "('
"
repeat while i < 6
select (insertion point before line i)
select line the (startLine of the selection)
copy (contents of the selection) as text to myText
set newText to text items of myText
set AppleScript's text item delimiters to {""}
set newText to newText as text
select insertion point after line 1
if i = 2 then
set selection to newText
else
set selection to "','" & newText
end if
set i to i + 1
end repeat
set selection to "')"
end tell
end tell
The issue is that result of the script is ('a','b','b'), so I am unable to remove 'new line' character. If someone help me to improve it to work with dynamic number of lines, I will be grateful.

Answer 1

To get the text from TextWrangler, you would use:
tell application "TextWrangler"
set myString to text of window 1
end tell
To update the text in TextWrangler, you use:
tell application "TextWrangler"
set text of window 1 to myString
end tell
So, you can wrap those two pieces of code around adayzdone's code.
tell application "TextWrangler"
set myString to text of window 1
end tell
set myList to paragraphs of myString
set listCount to count myList
repeat with i from 1 to my listCount
set item i of myList to quoted form of item i of myList
end repeat
set {TID, text item delimiters} to {text item delimiters, ", "}
set newString to ("(" & myList as text) & ")"
set text item delimiters to TID
tell application "TextWrangler"
set text of window 1 to myString
end tell

Answer 2

You can try something like this:
set myString to "a
b
c
d"
set myList to paragraphs of myString
set listCount to count myList
repeat with i from 1 to my listCount
set item i of myList to quoted form of item i of myList
end repeat
set {TID, text item delimiters} to {text item delimiters, ", "}
set newString to ("(" & myList as text) & ")"
set text item delimiters to TID
return newString