thanks, Elan... handy stuff.
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: Monday, September 18, 2000 4:09 PM
> To: [EMAIL PROTECTED]
> Subject: [REBOL] Even I make mistakes<g> Re:
>
>
> Hi Ralph,
>
> modules will hopefully reduce the likelyhood of name clashes in
> the future.
> For now I think that using objects helps to avoid this kind of errors in
> scripts that evolve over time.
>
> Another trick is to execute a trial run while PROTECTing all of
> those words
> that one wishes to keep unique. Name clashes will then become evident when
> a word is inadvertently reused.
>
> The following script can be helpful. Given a script file filename.r it
> writes a new filename.rp file.
>
> input: filename.r
> output: filename.rp
>
> When you DO the script filename.rp all globally defined words in this
> script will be PROTECTed. Attempting to redefine any of these words will
> result in an error message.
>
> How it works:
> The script prompts you for a filename or a directory name.
> If you provide a comma separated list of filename, the script will process
> all the filenames provided.
> If you provide a directory name the script will process all the files in
> that directory.
> Hit return if you want to process all script files in the current
> directory. You do not need to provide the current directory name.
>
> The script assumes that the files you wish to process have the extension
> ".r". If a filename does not have the ".r" extension, the script will add
> that extension, regardless of whether or not the filename contains a
> different extension.
>
> The script loads the script file, identifies tokens that will be
> defined in
> the global context by the script it loaded and creates a new script file
> that has the same filename as the original file. It replaces the ".r"
> extension by the extension ".rp".
>
> The script appends two things to the original script file which
> it saves in
> the
> .rp file.
> 1. A block called __set-words. This block contains all globally defined
> words in the script (with exception of words that are defined by using the
> set function.)
> 2. A foreach expression that protects all the words listed in the
> __set-words block.
>
> If you subsequently attempt to load a script that redefines the same word,
> you will get a word protected error, which will alert you to
> those globally
> defined words that are being redefined in this other script.
>
> You can easily test the script by first running it to generate a ".rp"
> file, DO the .rp file and then DO the original .r file.
>
> Example:
>
> 1. First prepare a .rp file:
>
> >> do %protect-words.r
> Script: "Protect-Words" (none)
>
> Note: Only files with a .r extension will be protected. They will be
> saved to
> a file that has the same name and the extension .rp.
> Please enter
> 1. the names of the files you wish to protect separated by
> commas; or
> 2. the qualified pathname to the directory containing the files you
> wish to protect; or
> 3. hit <enter> to protect all files with a .r extension in the
> current directory.
> >: %test-prscript.r
>
> 2. Now evaluate the .rp file
>
> >> do %test-prscript.rp
> Script: "Untitled" (none)
>
> 3. When you now try to redefine the globally defined word in
> test-prscript.rp by evaluating the original test-proscript.r file, you are
> notified of the attempt to redefine protected words:
>
> >> do %test-prscript.r
> Script: "Untitled" (none)
> ** Script Error: Word this is protected, cannot modify.
> ** Where: this: 1
> that: func []
>
> The file test-prscript.r contains the following script:
>
> REBOL []
>
> this: 1
> that: func [] [ x: 1]
> and-more: "this is more."
>
> The resulting file test-prscript.rp contains:
> REBOL []
>
> this: 1
> that: func [] [ x: 1]
> and-more: "this is more."
> __set-words: [and-more that this]
>
> foreach word __set-words [
> protect word
> ]
>
> The protect-words.r script file contains:
>
> REBOL
> title: "Protect-Words"
> file: %protect-words.r
> ]
> script: none
> set-words: none
> protect-set-words: {
> foreach word __set-words [
> protect word
> ]
> }
>
> dir: system/script/path
>
> read-script: func [filename [%file]] [
> set-words: make block! 100
> script: read filename
> filename
> ]
>
> collect-set-words: func [filename [file!] /local tokens] [
> set-words: make block! 100
> tokens: load/next filename
> while [not empty? tokens]
> if set-word? first tokens [
> insert set-words to word! first tokens
> ]
> tokens: load/next second tokens
> ]
> set-words
> ]
>
> make-protected-script: func [filename [file!] /local protected-filename
> tokens]
> tokens: mold collect-set-words read-script filename
> append script join newline "__set-words: "
> append script tokens
> append script join newline protect-set-words
> protected-filename: append filename #"p"
> write protected-filename script
> ]
>
> protect-these-files: ask {
> Note: Only files with a .r extension will be protected. They will be
> saved to
> a file that has the same name and the extension .rp.
> Please enter
> 1. the names of the files you wish to protect separated by
> commas; or
> 2. the qualified pathname to the directory containing the files you
> wish to protect; or
> 3. hit <enter> to protect all files with a .r extension in the
> current directory.
> >: }
> either found? find protect-these-files "," [
> protect-these-files: parse/all protect-these-files ","
> ][
> either empty? protect-these-files [
> protect-these-files: load %./
> ][
> either dir? load protect-these-files [
> dir: load protect-these-files
> if (last dir) <> #"/" [ append dir #"/" ]
> protect-these-files: load dir
> ][
> protect-these-files: load protect-these-files
> ]
> ]
> ]
>
> either block? protect-these-files [
> foreach file protect-these-files [
> if not found? find file ".r" [
> append file ".r"
> ]
> file: join dir load file
> if all [
> file? file
> not dir? file
> exists? file
> (last file) = #"r"
> ][
> make-protected-script file
> ]
> ]
> ][
> if not found? find file ".r" [
> append file ".r"
> ]
> make-protected-script protect-these-files
> ]
>
>
>
> At 10:02 AM 9/18/00 -0400, you wrote:
> >If anyone tried to order either REBOL FOR DUMMIES or REBOL: THE OFFICIAL
> >GUIDE yesterday, you found your order would not go through, even with all
> >the correct information. Why? Even I flub up on occasion. The
> forms are now
> >fixed and orders go though fine.
> >
> >The mistake was a dumb one (as opposed to a Dummies one) and I reveal it
> >since you may find such instructive in your own coding. I wrote
> this really
> >slick little credit card validation function (published earlier on this
> >list) Saturday. Tested it rigorously, and it worked fine. So I dropped it
> >into the order forms; tested them briefly; all seemed fine; so I
> went live
> >with the changes. Then I get e-mail this morning from a couple
> of people who
> >tried to order books yesterday and the orders would not record.
> Here's the
> >mistake! One of the REBOL words I defined in my credit card validation
> >function was the same as one in my form processing script (but
> the words, of
> >course, did different functions). This mismatch did not crash the script
> >(such would have pointed to an obvious problem) but rather caused a more
> >subtle misoperation; i.e. orders would not record.
> >
> >The moral of this tale? Document! I stress that in REBOL FOR
> DUMMIES. If you
> >don't document, scripts sometimes will coil around and bite you
> on the ....
> >well, anyway, I fixed it<g>.
> >
> >Best,
> >
> >--Ralph Roberts
> >Soldier of the REBOLution
> >
> >
> >
> >
>
> ;- Elan [ : - ) ]
> author of REBOL: THE OFFICIAL GUIDE
> REBOL Press: The Official Source for REBOL Books
> http://www.REBOLpress.com
> visit me at http://www.TechScribe.com
>
