Re: The merge function is redundant?
Folks:
I’m looking at Jan Schenkel’s posting on the “Power of Merge”.
I can’t make any of the examples work.
Obviously, there is some code or some very basic thing that everybody (but me)
knows, but ??
Please illuminate me. I see the " placeholder in some of the lessons. The
dictionary is no help.
BTW: No search in the dictionary’s user guide?
Thanks,
Bill
e.g.
on mouseUp
put "Testing" into Foobar
put merge("[[quote]]Foobar[[quote]] [[the short name of \
this stack]]") & return & \
merge("[[the layer of this card]] / [[the short ID \
of me]]") into tVariable
end mouseUp
Bill
William A. Prothero, Ph.D.University of California, Santa Barbara Dept. of
Earth Sciences (Emeritus)Santa Barbara, CA. 93105
http://earthlearningsolutions.org/
> On Jan 18, 2019, at 2:35 PM, kee nethery via use-livecode
> wrote:
>
> Thanks everyone. Templates makes sense.
>
> Just for grins, perhaps the dictionary entry could be enhanced with Jacque’s
> example.
>
> It makes sense to me now.
>
> Kee
>
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Re: The merge function is redundant?
Thanks everyone. Templates makes sense. Just for grins, perhaps the dictionary entry could be enhanced with Jacque’s example. It makes sense to me now. Kee ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: The merge function is redundant?
Kee, I can spend hours on why merge is useful and underappreciated but I will boil it down to one use case only: templates. Merge is crucial if you're assembling some textual template that is not LiveCode but want to generate parts of it in LiveCode. For example, the first step in understanding the power of merge is "variable interpolation" in which we use merge to place values inside our text, for example, consider the following HTML snippet: Name: [[tFirstName]] Surname: [[tSurname]] Email: [[tEmail]] --- Calling merge and having those variables filled with the data you want will get you the HTML you want. You can extrapolate it further by calling functions from merge such as: --- The current time is: [[the long english date]] --- You can even do loops and assemble more stuff. This is way better than error prone string concatenation. It is good for generating all sorts of textual formats, from HTML/XML to more niche stuff such as scripts to run in another language or even in LC itself. Cheers andre On 18/01/2019 18:33, kee nethery via use-livecode wrote: I’m confused. Can someone explain why merge function exists when the put function works just as well? merge( [[ 1 + 2 ]] = 3) vs put 1 + 2 && “= 3” What is it that merge can do that a put cannot do? Just asking because I don’t want LiveCode to end up like Perl where there are so many completely different ways to do the exact same thing that one person’s perl code can be unreadable to another equally talented Perl coder. Kee ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: The merge function is redundant?
> Kee N. wrote:
> I’m confused. Can someone explain why merge function exists when
> the put function works just as well?
> merge([[ 1 + 2 ]] = 3) vs put 1 + 2 && “= 3”
merge([[ 1 + 2 ]] = 3) produces a script error,
this should read merge("[[ 1 + 2 ]] = 3").
Merge is the one and only function to do *multiple* replacements in
large strings in *one* shot. This is especially *very* important when
setting wordy strings like htmltext (or emails, as JLG denoted).
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Re: The merge function is redundant?
kee nethery wrote: > I’m confused. Can someone explain why merge function exists when the > put function works just as well? > > merge( [[ 1 + 2 ]] = 3) > vs > put 1 + 2 && “= 3” > > What is it that merge can do that a put cannot do? Just asking because > I don’t want LiveCode to end up like Perl where there are so many > completely different ways to do the exact same thing that one person’s > perl code can be unreadable to another equally talented Perl coder. Not to worry about new things in the language stinking up the place. Merge has been in the xTalk family of languages for a long time, and serves a distinct purpose. A little history may be helpful: Gary Poppitz of the SuperCard team introduced the merge function to the xTalk world in the mid-90s, to support a server-side version of SuperCard called Flamethrower. The goal was to provide a convenient way to sprinkle xTalk evaluations and statements throughout text that isn't xTalk -- in that use-case, HTML. In short: templating. Without a merge function you'd need to write your own parse to walk through the text to find whatever delimiters you're using, then run the found substring through "do" or "value". Possible, but tedious and error-prone. Indeed there were some HyperCard stacks back in the day with similar functionality done in script (Bob McBurney's Arachnid comes to mind), so one could deliver dynamic web pages from a Mac server in our favorite language. But it was no speed demon compared to what LC does by handling that robustly in the engine. Some time around MetaCard v2.0 Scott Raney added it to the engine we now call LiveCode, so it's been around for more than 20 years. Mark Waddingham has enhanced it since then, and the core functionality is similar in many respects to how LC Server processes .lc files, so it's not going away any time soon. And considering its utility, I'm grateful for it. While I use it most often with HTML templates, I've used it with other formats as well for a wide range of tasks. The ability to quickly and conveniently process any number of LC Script placeholders within a body of non-LC text has many applications once you get the hang of it. Bonus: A sort of logical inverse to using LC expressions in the middle of non-LC text is to put non-LC text in the middle of LC Scripts. In bash this is done with heredoc, and some other languages offer such functionality as well. I've proposed it in the LC request queue: https://quality.livecode.com/show_bug.cgi?id=17471 Comment #5 there from Brian Milby shows existing syntax used in another xTalk, SenseTalk, that could conceivably be adopted, perhaps less useful for compatibility with that dialect than simply having proven design work already done. Used with the merge function, a heredoc-like implementation would make short work of many tasks we currently write "complicated"&space&"and"&space&"difficult-to-read"&space&"concatenation" for. -- Richard Gaskin Fourth World Systems Software Design and Development for the Desktop, Mobile, and the Web ambassa...@fourthworld.comhttp://www.FourthWorld.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: The merge function is redundant?
On 1/18/19 12:33 PM, kee nethery via use-livecode wrote: I’m confused. Can someone explain why merge function exists when the put function works just as well? merge( [[ 1 + 2 ]] = 3) vs put 1 + 2 && “= 3” What is it that merge can do that a put cannot do? For me, it's convenience, precision, and readability (no need for all those ampersands and quote marks.) I use it mostly for reports, auto-generated emails from my server, and sometimes dynamic HTML construction. It also eliminates the need for multiple "replace" commands. For example, imagine a text template in a custom property named "cText": Dear [[username]], Thank you for your interest in [[productname]]. [[productname]] is available for download at [[productURL]]. And the script: put "John Doe" into username put "Zygodact" into productname put "http://mydomain.com//zygodact.html"; into productURL put merge(the cText of me) into tResponse -- Jacqueline Landman Gay | jac...@hyperactivesw.com HyperActive Software | http://www.hyperactivesw.com ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: The merge function is redundant?
Folks, I’ve been following this discussion, barely. I don’t use merge, but when I need to form a command from several variables, I create the command as a text string and use do to execute it. So, when I look it up in the dictionary, I see a fairly simplistic description with nothing resembling the code being discussed in this thread. So I’m thinking: “What’s with the square brackets?” I haven’t looked at the link that Kee posted, (I’m having breakfast at the beach) but would like to make a request for the dictionary entry to be expanded. Best, Bill William Prothero http://ed.earthednet.org > On Jan 18, 2019, at 10:33 AM, kee nethery via use-livecode > wrote: > > I’m confused. Can someone explain why merge function exists when the put > function works just as well? > > merge( [[ 1 + 2 ]] = 3) > vs > put 1 + 2 && “= 3” > > What is it that merge can do that a put cannot do? Just asking because I > don’t want LiveCode to end up like Perl where there are so many completely > different ways to do the exact same thing that one person’s perl code can be > unreadable to another equally talented Perl coder. > > Kee > > > > ___ > use-livecode mailing list > use-livecode@lists.runrev.com > Please visit this url to subscribe, unsubscribe and manage your subscription > preferences: > http://lists.runrev.com/mailman/listinfo/use-livecode ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
Re: The merge function is redundant?
There's some overlap, but merge has (at least) one feature that put
doesn't: the ability to run code within its statement. A simple example:
put merge("The coin came up .")
The equivalent might be:
put "The coin came up" && item random(2) of "heads,tails" & "."
But consider this:
put 10 into myVar
put merge("The sum of the numbers from 1 to [[myVar]] is .")
There is no way to do that with a simple "put". You could unroll the code,
but for instances like what I'm planning to do with Navigator, that would
be totally unworkable.
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The merge function is redundant?
I’m confused. Can someone explain why merge function exists when the put function works just as well? merge( [[ 1 + 2 ]] = 3) vs put 1 + 2 && “= 3” What is it that merge can do that a put cannot do? Just asking because I don’t want LiveCode to end up like Perl where there are so many completely different ways to do the exact same thing that one person’s perl code can be unreadable to another equally talented Perl coder. Kee ___ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
