4

Is there way to get a Record by the value of one of its keys without looping?

I've been doing this:

set theKey to 22

set theRecords to {{key:11, value:"foo"}, {key:22, value:"bar"}}
repeat with theRecord in theRecords
    if key of theRecord = theKey then
      display dialog (key of theRecord as text) & ":" & value of theRecord
    end if
end repeat
3

I suppose that you are worried about the speed of iterating. Iterating would be a time of order-n O(n).

In AppleScript, you can possibly use a record of records instead of a list of records, but I believe that then the class of the key would have to be an identifier -- not integer like in your example.

Here is a link to somebody with a similar question: Emulating associative arrays in AppleScript

Lauri Ranta's answer is to use the command-line tool called "awk".

The solution that I toyed with was to make a faceless background app that would be what is called an "Agent" which AppleScript's could call upon for using its datastructures such as an associative array (also known as a dictionary or a Mapping.)

I didn't get my solution done. It's just an idea, but you could use Lauri's answer, she usually knows what she's talking about.

Since I know a little Pyton, and since Pyton comes with OS X, pre-installed in the System Folder, I would consider using Python myself.

I tried it again in "pure AppleScript" with the following code which I'm not really happy with:

set theRecords to {fooKey:{key:"fooKey", value:"fooValue"}, barKey:{key:"barKey", value:"barValue"}}
try
    set theRecord to get barKey of theRecords
    display dialog (key of theRecord & ":" & value of theRecord)
on error errorMessage number errorNumber
    if errorNumber is not equal to -128 then
        display dialog "No match"
    end if
end try

You can mix shell script and AppleScripts:

-- in AppleScript, you can call a shell script
do shell script "<enter your shell script here>"

Or, you can call an AppleScript from a shell script with the command-line tool called "osascript".

  • 1
    I had exactly the same question. What I don't understand is why AppleScript does not allow the following one-liner: (every item in theRecords whose key is theKey) or (first item in theRecords whose key is theKey). This would be very powerful and similar to Python's list comprehensions. – Bill Nov 26 '17 at 22:44

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