I posted this script at http://bbs.applescript.net/viewtopic.php?id=12758, which also should handle lower, UPPER, Title and Sentence.

Applescript:

property lower_alphabet : "abcdefghijklmnopqrstuvwxyz"
property upper_alphabet : "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
property white_space : {space, tab, return, ASCII character 10, ASCII character 13}

set this_string to "THIS STRING WILL COME BACK WITH THE FIRST LETTER OF EVERY WORD BEING A CAPITAL AND THE REST WILL BE LOWER CASE. Text containing punctuation: x-ray, don't."

get change_case(this_string, "Title")

on change_case(this_text, this_case)
   set new_text to ""
   if this_case is not in {"UPPER", "lower", "Title", "Sentence"} then
       return "Error: Case must be UPPER, lower, Title or Sentence"
   end if
   if this_case is "lower" then
       set use_capital to false
   else
       set use_capital to true
   end if
   repeat with this_char in this_text
       set x to offset of this_char in lower_alphabet
       if x is not 0 then
           if use_capital then
               set new_text to new_text & character x of upper_alphabet as string
               if this_case is not "UPPER" then
                   set use_capital to false
               end if
           else
               set new_text to new_text & character x of lower_alphabet as string
           end if
       else
           if this_case is "Title" and this_char is in white_space then
               set use_capital to true
           end if
           set new_text to new_text & this_char as string
       end if
   end repeat
   return new_text
end change_case

BTW, thank you Ray for re-enabling replies in Code Exchange!

UPPER, lower, Title works for me (in my script). Sentence really doesn't work, how obvious!
Yes, your's is much faster. I find your script quite difficult to understand in some spots, especially towards the end. Is their any chance you could make a commented version (with english variable names)?

Hi, kai. On a point of pendantry, since t is definitely a string or Unicode text at this point, not a list, its 'item 1' is properly its 'character 1'. Both work, but since there's no speed advantage either way, my vote's for clarity. 

Ditto. And we forgive the off-topic stickies in the OS X forum. 

To be honest, I'm having difficulty understanding how "lower" and "Title" can possibly work with uppercase input text - because I just can't see a mechanism for switching to lowercase when required. Here's my take on what happens...

At the start of your repeat loop, you have the following statements:

Since anything immediately below this relates to converting a lowercase character (and bearing in mind that we're tracking an uppercase character), we can skip straight to the corresponding 'else' statement further below:

Within the else section, we start with another if/then block, which may (or may not) change the value of the variable 'use_capital'. However, this can affect only what happens in the repeat loop's subsequent iteration (influencing how the next character is treated - and not the current one).

The next statement, 'set new_text to', etc., which does not refer or react to the value of 'use_capital' (or indeed anything else), will evidently be executed regardless. This surely means that the value of 'this_char' (an uppercase character) is added to the end of 'new_text' - whether 'this_case' is "lower", "Title", "Sentence" - or whatever.

That's the theory - but what of the practice? When I run your script, the returned values I get are, specifically:

Results:

These results are exactly what I'd have expected, given my understanding of your code - which is why I'm so puzzled as to why it should apparently work for you...

Can anyone please tell me what I'm missing in my analysis of Qwerty's script - and why his script should work for him (at least in "lower" and "Title" modes) - and not for me?

In fact, the only way I can get this particular approach to work - is to do something like this:

Applescript:

property lower_alphabet : "abcdefghijklmnopqrstuvwxyz"
property upper_alphabet : "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
property white_space : {space, tab, return, ASCII character 10, ASCII character 13}

on change_case(this_text, this_case)
   
   if this_case is not in {"UPPER", "lower", "Title", "Sentence"} then return "Error: Case must be UPPER, lower, Title or Sentence" -- can't continue
   
   set new_text to "" -- initialise the new string
   
   set use_capital to this_case is not "lower" -- if this_case is "lower", set use_capital to false (otherwise true)
   
   repeat with this_char in this_text
       
       if use_capital then
           
           set currentOffset to offset of this_char in lower_alphabet -- get alphabetical index of lowercase character
           if currentOffset is 0 then -- this_char is not lowercase anyway, so:
               set new_text to new_text & this_char -- don't change it
           else -- this_char is lowercase, so:
               set new_text to new_text & upper_alphabet's item currentOffset -- change it to uppercase
           end if
           
           
           if this_case is in {"Title", "Sentence"} then set use_capital to false -- next character should not use_capital
           
       else -- don't use_capital
           
           set currentOffset to offset of this_char in upper_alphabet -- get alphabetical index of uppercase character
           if currentOffset is 0 then -- this_char is not uppercase anyway, so:
               set new_text to new_text & this_char -- don't change it
           else -- this_char is uppercase, so:
               set new_text to new_text & lower_alphabet's item currentOffset -- change it to lowercase
           end if
           
           if this_char is in white_space and this_case is not "lower" then -- should next character use_capital?
               ignoring white space -- in case new_text already ends with white space
                   if this_case is "Title" or new_text ends with "." and this_case is "Sentence" then set use_capital to true -- next character should use_capital
               end ignoring
           end if
       end if
       
   end repeat
   return new_text
end change_case

Results:

Didn't your modified script aim to treat characters following white space in a similar way, Qwerty?

Title case is generally assumed to mean that each word's first character is uppercase, and that any remaining letters are lowercase. An alternative interpretation treats words in a broadly similar manner, apart from definite and indefinite articles (e.g. 'the' and 'a'), conjunctions (e.g. 'and') and prepositions (e.g. 'in', 'of'). These exceptions can consist of entirely lowercase characters.

For simplicity, I obviously based my script on the former definition. However, I don't really understand why, when considering title case, you question capitalising in this way. If you don't capitalise after white space, then surely most words would be lower case?

(I'm aware of some potential issues with the algorithm that I used, but I don't think they include the more common forms of white space.)

Thanks very much, Nigel. I'd noted your point previously about the behaviour of tids with Unicode text in Tiger - but hadn't yet assimilated the impact of changes affecting offset. Taking that script apart was driving me nuts! Just something else to watch out for - but that's progress I suppose.

And now that you've put my mind at rest, I can get some shuteye too. Thanks again, Mr. G. - and g'night, folks!

Gosh, what have I been missing out on! Sorry kai, I did mean "Sentence" case, not "Title", how stupid of me! Nigel, I'm using 10.3.9, so it's not only Tiger.
Does this work for you? (still slow):

Applescript:

(*
Evolved from Apple's 'Change Case of Item Names.scpt' - part of the Finder scripts.
You have the option of UPPER, lower, Title or Sentence cases.
Accepts non-alphabetic characters.
*)

property lower_alphabet : "abcdefghijklmnopqrstuvwxyz"
property upper_alphabet : "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
property white_space : {space, tab, return, ASCII character 10, ASCII character 13}

set this_string to "THIS STRING WILL COME BACK WITH THE FIRST LETTER OF EVERY WORD BEING A CAPITAL AND THE REST WILL BE LOWER CASE. Text containing punctuation: x-ray, don't."

get change_case(this_string, "Sentence")

on change_case(this_text, this_case)
   if this_case is not in {"UPPER", "lower", "Title", "Sentence"} then
       return "Error: Case must be UPPER, lower, Title or Sentence"
   end if
   set new_text to ""
   if this_case is "lower" then
       set use_capital to false
   else
       set use_capital to true
   end if
   repeat with i from 1 to count of this_text
       set this_char to character i of this_text
       ignoring case
           set x to offset of this_char in lower_alphabet
       end ignoring
       if x is not 0 then
           if use_capital then
               set new_text to new_text & character x of upper_alphabet as string
               if this_case is not "UPPER" then
                   set use_capital to false
               end if
           else
               set new_text to new_text & character x of lower_alphabet as string
           end if
       else
           if this_case is "Title" and this_char is in white_space then
               set use_capital to true
           else if this_case is "Sentence" and this_char is "." and ¬
               i is not (count of this_text) and ¬
               character (i + 1) of this_text is in white_space then
               set use_capital to true
           end if
           
           set new_text to new_text & this_char as string
       end if
   end repeat
   return new_text
end change_case

Hi, Qwerty. Gosh! Nothing like a bit of confusion to start the day.    If you and kai are both using Panther, I've no idea why your script works for you and not for him. However, what I said last night about the script working in Tiger but not in Jaguar still seems to be true.

I hadn't checked "Sentence" mode then. My results with that this morning are:

JAGUAR:
Both versions of your script capitalise the first letter of a sentence if it was lower case, but capitalise the second letter too if the first was already upper case. (And the third if the first two were already upper case, etc.)

TIGER:
Your first version capitalises the first letter of the first sentence, but actively lower-cases the first letter of subsequent sentences. The second version appears to work OK, but not, of course, if the previous sentence ends with a question mark, exclamation mark, or quote.

Putting the 'offset' line in an 'ignoring case' block has no effect. 'Ignoring' is the default setting for case where 'ignoring' and 'considering' apply. In Jaguar (and Panther?), they don't apply: 'offset' is exclusively case sensitive.

Here's a version of your approach that works properly in both Jaguar and Tiger. Obviously it'll need a longer alphabet if it's likely to encounter diacritical characters.

Applescript:

property alphabet : "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
property white_space : {space, tab, return, ASCII character 10, ASCII character 13}
property terminators : ".!?"

set this_string to "THIS STRING WILL COME BACK WITH THE FIRST LETTER OF EVERY WORD BEING A CAPITAL AND THE REST WILL BE LOWER CASE. Text containing punctuation: x-ray, don't." as Unicode text

get change_case(this_string, "title")

on change_case(this_text, this_case)
   set new_text to {}
   if this_case is not in {"UPPER", "lower", "Title", "Sentence"} then
       return "Error: Case must be UPPER, lower, Title or Sentence"
   end if
   
   set is_upper_mode to (this_case is "UPPER")
   set is_title_mode to (this_case is "Title")
   set is_sentence_mode to (this_case is "Sentence")
   set use_capital to (this_case is not "lower")
   if (this_text's class is Unicode text) then
       set alpha to alphabet as Unicode text
   else if (this_text's class is string) then
       set alpha to alphabet as string
   else
       display dialog "OH NO! WE'RE ALL GOING TO DIE!" buttons {"AAAGGHHH!"} default button 1 with icon caution
       error number -128
   end if
   
   considering case -- for speed and to customise 'offset' in Tiger
       repeat with this_char in this_text
           set x to offset of this_char in alpha
           if (x > 0) then
               if (use_capital) then
                   set end of new_text to character ((x - 1) mod 26 + 27) of alpha
                   set use_capital to (is_upper_mode)
               else
                   set end of new_text to character ((x - 1) mod 26 + 1) of alpha
               end if
           else
               if (is_sentence_mode and this_char is in terminators) or (is_title_mode and this_char is in white_space) then
                   set use_capital to true
               end if
               set end of new_text to this_char's contents
           end if
       end repeat
   end considering
   
   set astid to AppleScript's text item delimiters
   set AppleScript's text item delimiters to ""
   tell new_text to set new_text to its beginning & its rest
   set AppleScript's text item delimiters to astid
   return new_text
end change_case

PS. This is nothing to do with your latest post, which I've only just seen. What do you mean by tab "bug"?

PPS. kai doesn't seem to take much sleep, does he? 

The tab bug is where  "gibberish    gibberish" (gibberish«tab»gibberish), when converted to sentence case, is "Gibberish    Gibberish" in kai's script. The second word should not be capitalized.
P.S. Yes, kai seems to be full time on this forum.

P.P.S. Good point about the different sentence terminators!?.!

It may be worth noting that, on long strings, Qwerty's rewrite will break due to a stack overflow error. OMM, it tripped over a string (based largely on those tested earlier) of 57,586 characters. (As some of you will know, the overflow threshold can vary considerably, depending on string content - and possibly on OS, too. In the most extreme cases, it might even be as low as 4000 - 5000 characters.) In addition, a few sentence case issues still remain (to which I may now have a solution, of sorts). These include white space at the beginning of a string and multiple white spaces following a full point.

However, I'm slightly concerned that this thread is kinda 'growing like topsy' for a Code Exchange item. Since I feel somewhat responsible for much of the noise, now might be an appropriate time for me to bow out (to attend, anyway, to a rather pressing local issue) - and to leave the conclusion of this lively discussion to you good guys. I look forward to seeing the results with great interest.

That's just one of the burdens of a perpetual insomniac, Nigel. Can play havoc with one's social life, too!

Last edited by kai (2005-07-09 10:11:17 am)

Using my rewrite of kai's, I can use this code to generate the input string and it still does not crash for me (using his reply to me as the source text ). I don't know what the problem is?

Applescript:

set this_string to ""
repeat until (count of this_string) > 500000
   set this_string to this_string & "It may be worth noting that, on long strings, Qwerty's rewrite will break due to a stack overflow error. OMM, it tripped over a string (based largely on those tested earlier) of 57,586 characters. (As some of you will know, the overflow threshold can vary considerably, depending on string content - and possibly on OS, too. In the most extreme cases, it might even be as low as 4000 - 5000 characters.) In addition, a few sentence case issues still remain (to which I may now have a solution, of sorts). These include white space at the beginning of a string and multiple white spaces following a full point.

However, I'm slightly concerned that this thread is kinda 'growing like topsy' for a Code Exchange item. Since I feel somewhat responsible for much of the noise, now might be an appropriate time for me to bow out (to attend, anyway, to a rather pressing local issue) - and to leave the conclusion of this lively discussion to you good guys. I look forward to seeing the results with great interest. "
end repeat

No, I'm not really familiar with this. It seems so logical! Anyway, my rewrite of kai's cannot handle Unicode text, and so is inferior. We also need to watch out for things like 'I', in sentence case it is not capitalized.

Apologies for the delayed response, NovaScotian. I believe I wrote the comments that prompted your reply - but I take your point about the possible usefulness of such discussions. (Indeed, I've found the discussion of differences in script behaviour between OS versions quite illuminating.)

I’ve therefore added a further version (below) that sacrifices some speed & brevity to address several of the issues discussed previously. In exploring these, it's clear that a comprehensive solution might be possible only with access to a substantial dictionary (proper nouns, acronyms, etc.) - which is perhaps beyond the scope of a relatively simple script such as this. (The script introduces various properties, partly to accelerate runtime execution, but also to accommodate any further adjustments that might be considered necessary.)

I might be able to clear up the confusion there, Nigel. At the time, I was working in Jaguar (not Panther) - which would explain the differences in behaviour. (However, for the record, the script below was written and tested in Tiger).

The problem to which I was referring is a stack overflow error (errOSAStackOverflow: -2706), rather than a crash. In older versions of the Mac OS (including some versions of Mac OS X), the error can occur when the resulting number of string elements (text items, characters [items], words or paragraphs) exceeds about 4,060 (the precise figure can vary).

So, apart from getting a list of characters, the problem has very little to do with actual string length - since it depends primarily on the number of resulting string elements.

While such considerations may be of little concern to those using later versions of the Mac OS, they may still be worth noting for anyone interested in portability (for example, if a script is to be distributed generally - such as in a forum like this).

In later versions, the limit appears to have been removed. However, the algorithm to achieve this seems somewhat buggy - and, where there may be several thousand string elements involved, the dreaded, ever-spinning beach ball can appear. (The point at which this occurs appears to vary quite considerably, so it’s difficult to pin it down with any precision. OMM, it’s very likely to occur above 300,000 or 400,000 items - but has sometimes struck at around 60,000 items.)

Silent hanging aside, there also appear to be efficiency issues when getting particularly long lists of string elements - which may therefore take a disproportionate time to evaluate.

I've now modified my original ‘textItems’ handler (see script below) in an effort to side-step all three issues. So far, it seems to have worked quite effectively - as demonstrated by the following results (all the usual caveats for interpreting execution times apply):

                execution time (secs)
number of        with    without
text items    handler    handler

    1000        0.01          0.01

  10000        0.2            0.5
  20000        0.4            3.8
  30000        0.7            7.8
  40000        1.1          11.7
  50000        1.4          25.1
  60000        1.9          40.8
  70000        2.0          42.7
  80000        2.7          68.5
  90000        3.6        127.8
100000        4.7        138.2

The following version introduces an additional option for case type: "mixed" - a variation of title-case that renders definite and indefinite articles, conjunctions and prepositions as lowercase (except where they start a sentence):

Applescript:

-- syntax : changeCase of someText to caseType
-- someText (string) : plain or encoded text
-- caseType (string) : the type of case required ("upper", "lower", "sentence", "title" or "mixed")

-- "upper" : all uppercase text (no exceptions)
-- "lower" : all lowercase text (no exceptions)
-- "sentence" : uppercase character at start of each sentence, other characters lowercase (apart from words in sentenceModList)
-- "title" : uppercase character at start of each word, other characters lowercase (no exceptions)
-- "mixed" : similar to title, except for definite and indefinite articles, conjunctions and prepositions (see mixedModList) that don't start a sentence

property lowerStr : "abcdefghijklmnopqrstuvwxyzáàâäãåæçéèêëíìîïñóòôöõøœúùûüÿ"
property upperStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZÁÀÂÄÃÅÆÇÉÈÊËÍÌÎÏÑÓÒÔÖÕØŒÚÙÛÜŸ"
property alphaList : lowerStr's characters & reverse of upperStr's characters
property sentenceBreak : {".", "!", "?"}
property wordBreak : {space, ASCII character 202, tab}
property everyBreak : wordBreak & sentenceBreak
property whiteSpace : wordBreak & {return, ASCII character 10}
property currList : missing value
property sentenceModList : {"i", "i'm", "i’m", "i've", "i’ve", "I’ve", "I've", "I’m", "I'm", "I"} (* could be extended to include certain proper nouns, acronyms, etc. *)
property mixedModList : {"By Means Of", "In Front Of", "In Order That", "On Account Of", "Whether Or Not", "According To", "As To", "Aside From", "Because Of", "Even If", "Even Though", "In Case", "Inside Of", "Now That", "Only If", "Out Of", "Owing To", "Prior To", "Subsequent To", "A", "About", "Above", "Across", "After", "Against", "Along", "Although", "Among", "An", "And", "Around", "As", "At", "Because", "Before", "Behind", "Below", "Beneath", "Beside", "Between", "Beyond", "But", "By", "De", "Down", "During", "Except", "For", "From", "If", "In", "Inside", "Into", "Like", "Near", "Of", "Off", "On", "Onto", "Or", "Out", "Outside", "Over", "Past", "Since", "So", "The", "Though", "Through", "Throughout", "To", "Under", "Unless", "Until", "Up", "Upon", "When", "Whereas", "While", "With", "Within", "Without", "Ye", "ye", "without", "within", "with", "while", "whereas", "when", "upon", "up", "until", "unless", "under", "to", "throughout", "through", "though", "the", "so", "since", "past", "over", "outside", "out", "or", "onto", "on", "off", "of", "near", "like", "into", "inside", "in", "if", "from", "for", "except", "during", "down", "de", "by", "but", "beyond", "between", "beside", "beneath", "below", "behind", "before", "because", "at", "as", "around", "and", "an", "among", "although", "along", "against", "after", "across", "above", "about", "a", "subsequent to", "prior to", "owing to", "out of", "only if", "now that", "inside of", "in case", "even though", "even if", "because of", "aside from", "as to", "according to", "whether or not", "on account of", "in order that", "in front of", "by means of"}

on textItems from currTxt
   tell (count currTxt's text items) to if it > 4000 then tell it div 2 to return ¬
       my (textItems from (currTxt's text 1 thru text item it)) & ¬
       my (textItems from (currTxt's text from text item (it + 1) to -1))
   currTxt's text items
end textItems

on initialCap(currTxt)
   tell currTxt to if (count words) > 0 then tell word 1's character 1 to if it is in lowerStr then
       set AppleScript's text item delimiters to it
       tell my (textItems from currTxt) to return beginning & upperStr's character ((count lowerStr's text item 1) + 1) & rest
   end if
   currTxt
end initialCap

to capItems from currTxt against breakList
   repeat with currBreak in breakList
       set text item delimiters to currBreak
       if (count currTxt's text items) > 1 then
           set currList to my (textItems from currTxt)
           repeat with n from 2 to count currList
               set my currList's item n to initialCap(my currList's item n)
           end repeat
           set text item delimiters to currBreak's contents
           tell my currList to set currTxt to beginning & ({""} & rest)
       end if
   end repeat
   currTxt
end capItems

on modItems from currTxt against modList
   set currList to modList
   set currCount to (count modList) div 2
   repeat with currBreak in everyBreak
       set text item delimiters to currBreak
       if (count currTxt's text items) > 1 then repeat with n from 1 to currCount
           set text item delimiters to my currList's item n & currBreak
           if (count currTxt's text items) > 1 then
               set currTxt to textItems from currTxt
               set text item delimiters to my currList's item -n & currBreak
               tell currTxt to set currTxt to beginning & ({""} & rest)
           end if
       end repeat
   end repeat
   currTxt
end modItems

to changeCase of currTxt to caseType
   if (count currTxt's words) is 0 then return currTxt
   
   ignoring case
       tell caseType to set {upper_Case, lower_Case, sentence_Case, title_Case, mixed_Case} to {it is "upper", it is "lower", it is "sentence", it is "title", it is "mixed"}
   end ignoring
   
   if not (upper_Case or lower_Case or title_Case or sentence_Case or mixed_Case) then
       error "The term \"" & caseType & "\" is not a valid case type option. Please use \"upper\", \"lower\", \"sentence\", \"title\" or \"mixed\"."
   else if upper_Case then
       set n to 1
   else
       set n to -1
   end if
   
   considering case
       set tid to text item delimiters
       
       repeat with n from n to n * (count lowerStr) by n
           set text item delimiters to my alphaList's item n
           set currTxt to textItems from currTxt
           set text item delimiters to my alphaList's item -n
           tell currTxt to set currTxt to beginning & ({""} & rest)
       end repeat
       
       if sentence_Case then
           set currTxt to initialCap(modItems from (capItems from currTxt against sentenceBreak) against sentenceModList)
       else if title_Case or mixed_Case then
           set currTxt to initialCap(capItems from currTxt against whiteSpace)
           if mixed_Case then set currTxt to initialCap(capItems from (modItems from currTxt against mixedModList) against sentenceBreak)
       end if
       
       set text item delimiters to tid
   end considering
   currTxt
end changeCase

set someText to "How far you go in life depends on your being TENDER with the YOUNG, COMPASSIONATE with the AGED, SYMPATHETIC with the STRIVING and TOLERANT of the WEAK and STRONG. Because SOMEDAY in your life you will have been ALL of these." (* George Washington Carver. *)

changeCase of someText to "upper" (* "upper", "lower", "sentence", "title" or "mixed" *)

Script subsequently edited to insert underscore characters in certain variable labels (see discussion below)

Results:

Apologies for the length of all this...

Last edited by kai (2005-07-24 11:02:16 am)