oh great! thanks! :) I thought noone read that huge mail, lol.. KKRT
On Mon, Jun 04, 2007 at 06:08:13PM +0100, Tom Hennigan wrote: > Okay I've got round to putting it on the wiki > (http://amsn-project.net/wiki/Dev:TclTk_Tutorial). I didn't put > anything about multiline commands yet. But I think everything else is > there! > > - Tom > > On 5/31/07, Youness Alaoui <[EMAIL PROTECTED]> wrote: > > Yeah, you reminded me of something... > > Most 'common problems' with tcl/tk are the "lists theory", substitution > > theory, and command theory. > > In short, the 'lists theory' is that everything is a list, and tcl works a > > lot with list manipulations. > > substitution theory is that, if I do "function $arg" the $arg will be > > substituted, and if it had a space, the > > 'function' will get two arguments, if I do {function $arg} (the {} means > > it's a list) the $arg will not be > > substituted and the argument will be the same as if I wrote "function > > \$arg". If I do [list function $arg] then > > $arg will be substituted but if it had a space in it, it will still count > > as one argument (not two like > > before).. actually $arg will become a list element. > > Example : > > set file "c:\My documents\file.txt" > > if you do > > button .b -command "open $file" > > then it will fail because it would be the same as doing : > > button .b -command "open c:\My documents\file.txt" > > (this is what will be stored), so once evaluated, it will evaluate "C:\My" > > as the first argument and > > "documents\file.txt" as the second argument. > > If you do : > > button .b -command {open $file} > > then it will fail because it will say "$file : file not found" unless you > > create a file named "$file" > > if you do : > > button .b -command [list open $file] > > then it will work because Tcl will store the callback as : {open {C:\My > > documents\file.txt}} (a list with two > > elements, the first being the command, the second being the argument). > > and finally, about the 'command theory', it's to say that EVERYTHING is a > > command. even 'if'.. so the if is a > > command which takes : > > if expression body ?elseif body? ?elseif body? ... ?else body? > > so if you do : > > if $a return > > it works, if you want to do : > > if $a == $b return > > it won't work because you sent "$a" as one argument "==" as a second > > argument (the body '==' is invalid, it > > would say that '==' is not a valid command) and $b as the third argument > > (again error because it only accepts > > else and elseif) and return as the 4th argument. So you group them into a > > list : > > if {$a == $b} return > > the {$a == $b} becomes a list. You could have also done : > > if [list $a == $b] return > > but it's better to put braces, and the 'if' command will evaluate the > > expression and *substitute in the parent > > namespace* (which is why it works, even if { } will disable substitution). > > Also, you CAN'T do : > > if {$a == $b} { > > return 0 > > } > > else > > { > > return 1 > > } > > > > because it will say "else : invalid command". The commands are delimited by > > either a ';' or by a newline, so > > when you close the brace after the if and go to the next line, it means > > that you finished with the 'if'. This > > means you HAVE to put the 'else' on the same line as the closing brace of > > the body, like this : > > if {$a == $b} { > > return 0 > > } else { > > return 1 > > } > > The same applies for the 'else' you can't put a newline after the 'else', > > otherwise it will say "{ : invalid > > command". > > You can put newlines inside the body of the if only because we do a { } (if > > you do [list] you'll need to put a > > backslash at the end of each line otherwise it will say "missing close > > bracket", like this : > > if {$a == $b} [list \ > > return 0 \ > > ] else [list \ > > return 1 > > ] > > but you DON'T WANT TO DO THIS because... well, remember { } allows you to > > disable substitution, so if you do for > > example : > > if {$a == $b} [list return [exit]] > > then when evaluation the 'if', the [list return [exit]] will be evaluated > > (to go as an argument of the if) and > > 'exit' will be called even if $a != $b. > > So to continue, when you do the { }, nothing is evaluated, so if you do > > if { $a == $b } { > > return 0 > > } > > then if will get 2 arguments, the first being the expression and the second > > being a list containing multiple > > elements : a newline, a series of spaces, a 'return', a '0' and a newline. > > When the 'if' will evaluated that > > list, it will be evaluated as code and the variables/commands will be > > substituted/evaluated and the newlines > > will be interpreted as command delimiters. > > You can also do something like this : > > set body { whatever_function $arg > > return 0 > > } > > if {$a == $b} $body > > and since $body is not between { } it will be replaced by the code above... > > beware, if you did : > > if {$a == $b} {$body } > > then $body will only be substituted AFTER the if is entered and will be > > evaluated as one command, it will say > > that : > > {whatever_function $arg > > return 0 > > } : invalid command > > > > oh and yes, if you were meant to ask, yes, you can put newlines and put > > spaces in a command, so if you do : > > proc {a > > b > > c} { } {puts 'abc called'} > > > > a command called {a > > b > > c} will be created. And you can call it with > > {a > > b > > c} > > or with : > > set command "a\nb\nc" > > $command > > > > it's fun Tcl, right ? you just need to understand those three basics, > > anything is a command getting executed.. > > the tcl keywords are just 'built-in' commands (like if), understand lists > > and substitutions... and once you get > > that, you can do a lot of fancy stuff (like commands with spaces or > > newlines in them :p) > > > > Finally, here are three interesting links in the forums in which I > > explained what I just explained in this mail, > > a bit differently, maybe better, with other examples, and probably with a > > bit more info. So please read them > > too. > > http://www.amsn-project.net/forums/viewtopic.php?p=17467 > > http://www.amsn-project.net/forums/viewtopic.php?p=5801#5801 > > http://www.amsn-project.net/forums/viewtopic.php?p=4461#4461 > > > > and I would REALLY love it if someone could summarize all this (or just > > copy/paste it?) to the wiki in a page > > like Dev:Tcl/Tk_Tutorials > > > > > > > > p.s.: I never tried/tested the commands with newlines, but I'm guessing > > they will work,I know that if I had put > > $body, it will tell me an error trying to execute a command containing the > > newline, but I never created one in > > itself. > > > > Thanks and have fun! > > KaKaRoTo > > > > > > On Thu, May 31, 2007 at 12:05:49AM +0200, Mirko Hansen wrote: > > > Wow thanks a lot everybody for this nice welcome. It's a real pleasure to > > > me. I think I should introduce myself roughly. Well, I think you all > > > already > > > know, but my name is Mirko. ;) I'm 24 years old, living in Germany, and > > > actually I'm studying computer science at university. It's sometimes > > > really > > > time-consuming, especially if we have those really nice homeworks like the > > > last two days, but I hope I'll be of use for the team, anyway I'll give my > > > best to. As Youness said, I'm very new to TCL, I never had to deal with it > > > before, so I would be really grateful if you advise me of my possibly made > > > mistakes, to be able to learn from them. :) > > > > > > I think you'll hear from me soon. To a great teamwork! :) > > > > > > Bye, > > > Mirko > > > > > > 2007/5/30, Youness Alaoui <[EMAIL PROTECTED]>: > > > > > > > >yeah, sounds intriguing right ? > > > >well, baaazen is the username of Mirko. And this mail is to announce that > > > >he's been added as part of the team. > > > >So everyone, please welcome Mirko into the team, and please be helpful. > > > >Mirko, if you need anything, don't hesitate to ask. I think you've been > > > >following the ML for a little while now > > > >so you should know how we work. in short ; > > > >1 - a bugfix, you can commit > > > >2 - a change to the UI should be discussed > > > >3 - a change of behavior should be discussed > > > >4 - a new feature should be discussed. > > > > > > > >Mirko is still studying and won't have much time (like everyone else) but > > > >he promised to do his best to try and > > > >help. He doesn't know much Tcl but from the patches he sent, it shows > > > >that > > > >he's very skilled and I'm sure he'll > > > >learn it all pretty soon. > > > > > > > >KaKaRoTo > > > > > > > >------------------------------------------------------------------------- > > > >This SF.net email is sponsored by DB2 Express > > > >Download DB2 Express C - the FREE version of DB2 express and take > > > >control of your XML. No limits. Just data. Click to get it now. > > > >http://sourceforge.net/powerbar/db2/ > > > >_______________________________________________ > > > >Amsn-devel mailing list > > > >Amsn-devel@lists.sourceforge.net > > > >https://lists.sourceforge.net/lists/listinfo/amsn-devel > > > > > > > > > ------------------------------------------------------------------------- > > > This SF.net email is sponsored by DB2 Express > > > Download DB2 Express C - the FREE version of DB2 express and take > > > control of your XML. No limits. Just data. Click to get it now. > > > http://sourceforge.net/powerbar/db2/ > > > _______________________________________________ > > > Amsn-devel mailing list > > > Amsn-devel@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/amsn-devel > > > > > > ------------------------------------------------------------------------- > > This SF.net email is sponsored by DB2 Express > > Download DB2 Express C - the FREE version of DB2 express and take > > control of your XML. No limits. Just data. Click to get it now. > > http://sourceforge.net/powerbar/db2/ > > _______________________________________________ > > Amsn-devel mailing list > > Amsn-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/amsn-devel > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. 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