AppleScript清單及其子句

Question

AppleScript初學者在這裏，仍然苦於基本的語法。

這工作：

tell application "Mail" 
    set flagged to messages of inbox whose flagged status is true 
    log count of flagged 
end tell 

這不起作用：

tell application "Mail" 
    set msgs to messages of inbox 
    set flagged to msgs whose flagged status is true 
    log count of flagged 
end tell 

爲什麼？ （我懷疑它是在逃避我一個簡單的語法規則）

Answer 1

當你寫set msgs to messages of inbox，你真正想說的是set msgs to GET messages of inbox作爲AppleScript的自動執行命令get如果你不告訴它，否則，其結果是（消息引用）一個AppleScript列表，如：

{message id 123 of mailbox "Inbox" ..., message 124 of mailbox "Inbox" ...} 

然而，whose查詢（引用）只能在應用對象的工作，而不是AppleScript的列表，如：

every item of {1, 2, 3, 4, 5} where it > 3 
-- error "Can’t get {1, 2, 3, 4, 5} whose it > 3." number -1728 

請嘗試改爲：

tell application "Mail" 
    set msgs to a reference to messages of inbox 
    set flagged to msgs whose flagged status is true 
    log count of flagged 
end tell