Manipulating word chunks

[phaworth]

I have a need to extract the first word of all the lines in a variable.

I have been trying:

Code: Select all

get word 1 of all lines of myvariable

and

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get word 1 of line 1 to (the number of lines in myvariable) of my variable

The first try resulted in a compilation error and the second returned zero, which is the value of word 1 of the first line but no other values.

What is the correct way to achieve this? Do I have to use a repeat loop to go through all the lines and extract the first word from each one or is there a better way?

Thanks,
Pete

[Mark]

Hi Pete,

Yes, a "repeat for each" loop is probably the simplest and fastest solution.

Best,

Mark

[shadowslash]

Try this small bit of code I made..

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on mouseUp
   repeat with x=1 to the num of lines in myVariable
      get the first word of line x of myvariable
   end repeat
end mouseUp

[Janschenkel]

The script as proposed by shadowslash will definitely work, but can be optimized. This should be faster for longer texts:

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on mouseUp
   repeat for each line theLine in myVariable 
      put the first word of theLine & return after theFirstWordList 
   end repeat 
   -- strip the trailing return
   delete the last char of theFirstWordList
end mouseUp

When you use a repeat for each line loop, the engine will go through the data one line at a time, and can remember where it's at in the variable.
If you use a repeat with theIndex = 1 to the number of lines loop, the engine has to start counting lines again from the very beginning of the text, in order to find line theIndex of the data.

Also, when you use a repeat with loop, it's faster to evaluate the end value just once - otherwise the engine may have to recount every time, just to make sure it hasn't gone too far. So it's faster to:

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put the number of lines in theVariable into theCount
repeat with theIndex = 1 to theCount
   ...
end repeat

Anyway, using repeat for each can improve performance dramatically, and it's best to pick up on these peculiarities of the language as quickly as possible

Jan Schenkel.

[shadowslash]

I modified Janschenkel's script a bit and I came up with this:

Code: Select all

on mouseUp
   repeat for each line theLine in myVariable
      get the first word of theLine
      if theFirstWordList is empty then
         put it into theFirstWordList
      else
         put it & return after theFirstWordList
      end if
   end repeat
   -- strip the trailing return
   delete the last char of theFirstWordList
end mouseUp

This ensures that there isn't an empty line at the end of theFirstWordList variable. Alternatively, you can also use:

Code: Select all

delete the last line of theFirstWordList

to make your code smaller but then it's really up to you.

[Klaus]

You could also use an array!

...
set columndelimiter to SPACE
split myVariable by column
put myVariable[1] into list_of_first_words
...

Done


Best

Klaus

[Mark]

Dear shadowslash and Klaus,

Don't use additional if statements only to delete one character at the end. It slows down your script.

Don't use arrays in a repeat loop either. This slows down your script significantly.

Best,

Mark

[Klaus]

Dag Mark,

I NEVER did, do or will do this!


Best

Klaus

[shadowslash]

You could also use an array!

...
set columndelimiter to SPACE
split myVariable by column
put myVariable[1] into list_of_first_words
...

Done


Best

Klaus

Lol arrays are like ancient hieroglyphics to me... Eventhough I already am doing a lot of stuff through Revolution, I haven't even DARED try using an array statement yet.

[!Jerry!]

I modified Janschenkel's script a bit and I came up with this:

Code: Select all

on mouseUp
   repeat for each line theLine in myVariable
      get the first word of theLine
      if theFirstWordList is empty then
         put it into theFirstWordList
      else
         put it & return after theFirstWordList
      end if
   end repeat
   -- strip the trailing return
   delete the last char of theFirstWordList
end mouseUp

Hi shadowslash,

are you sure, that your modification is right?
It seems to me you would get two non-separate words in the first line of "theFirstWordList" ...

regards,
Jerry

[phaworth]

Thanks for all the ideas. I haven't been getting emails about the posts so have only just seen them all. The info about the efficiency considerations in repeat loops is great, thanks for that

I have a repeat loop at the moment that is doing the job for me but the simplicity of using an array is appealing. Would be interesting to measure the efficiency of the array approach vs a repeat loop, although I don;t expect to have enough data for it to make an appreciable difference (a few hundred lines at most).

If anyone from RunRev is watching, I can't help feeling that there should be a way to do this with something like "get word 1 of all lines of myVariable".

Pete

[shadowslash]

Hi shadowslash,

are you sure, that your modification is right?
It seems to me you would get two non-separate words in the first line of "theFirstWordList" ...

regards,
Jerry

Hi Jerry,

Thanks for reminding me! I didn't see that one.

Code: Select all

on mouseUp
   repeat for each line theLine in myVariable
      get the first word of theLine
      if theFirstWordList is empty then
         put it into theFirstWordList
      else
         put it & return after theFirstWordList
      end if
   end repeat
end mouseUp