@FaheemMitha Well you said a.lua and b.lua have shared code, so I imagined they would both require("foo.lua"), which would contain those shared functions
@FaheemMitha you either need to arrange that the local definition is in scope where you need it, or declare it as a global, impossible to say in general.
In Douglas Adams' sci-fi series "The Hitchhiker's Guide to the Galaxy," a pair of programmers task the galaxy's largest supercomputer with answering the ultimate question of the meaning of life, the universe and everything. After 7.5 million years of processing, the computer reaches an answer: 42. Only then do the programmers realize that nobody knew the question the program was meant to answer. Now, in this week's most satisfying example of life reflecting art, a pair of mathematicians have used a global network of 500,000 computers to solve a centuries-old math puzzle that just happens to…
$ a68g
Algol 68 Genie 2.8.4
Copyright 2016 Marcel van der Veer <algol68g@xs4all.nl>.
This is free software covered by the GNU General Public License.
There is ABSOLUTELY NO WARRANTY for Algol 68 Genie;
not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
Please report bugs to Marcel van der Veer <algol68g@xs4all.nl>.
Usage: a68g [options | filename]
For help: a68g --apropos [keyword]
@PauloCereda I had friends in cs at the time who did a lot of algol68 as one of the professors at Manchester was I think one of the editors of the spec, I'll check:-)
@PauloCereda in first year of pure maths they inflicted real analysis on us where it took the whole of the first term to be able to construct a model of the real numbers via Dedekind cuts (which thinned out the audience a bit) I think they used the first year algol68 course in the same way in cs, people who came thinking they could already program having to learn about 15 levels of dereferencing before they could work out what a variable meant:-)
So, a more specific Lua question. Say in a.lua, there is an array called Tables={}, for example. Then I need to access Tables from b.lua. If it's local I can't access it. But is there some way to not make it global, but still access it from b.lua?
Actually, in Python a file is automatically a namespace. But it doesn't seem to be the same thing in Lua. E.g. in Python, import foo would means that everything from foo.py would be made available within the foo namespace.
@FaheemMitha I don't think it's fair to compare these two languages, it's like mixing apples with oranges. The import's from Python are basically what require does in Lua, and the return of require is a namespace.
But as @JosephWright said, there's nothing but tables in Lua.
local charcat_table = l3kernel.charcat_table or 1
local function charcat(charcode, catcode)
setcatcode(charcat_table, charcode, catcode)
sprint(charcat_table, utf8_char(charcode))
end
l3kernel.charcat = charcat
@PauloCereda Also doable, though that depends on you not wanting globals, whereas for the L3 core stuff, we really do (as they are supposed to sort-of work like TeX macros)
@FaheemMitha It's just an observation really: it's how Lua works, so everything else is syntactic sugar
@FaheemMitha It depends what you want to do: Lua was designed for certain light-weight applications, and its good for those
@FaheemMitha I find the whole namespace business quite odd, I guess because I'm a TeX programmer: having multiple things with the same name seems to be to be a recipe for confusion ...
@JosephWright Namespaces can be useful under certain circumstances, such as when sharing stuff between different files. And there are standard names for some local variables, at least. But you don't want them to propagate.
@JosephWright In this case, does it mean that all the globals from shared would not be visible in b?
@FaheemMitha I mean that as a TeX programmer, I'm used to have \foo@bar@baz and \bong@bar@baz, so I never have to think 'what's the meaning of \baz here?'
If there are multiple files, one presumably doesn't want to import them all for usage in some other place. Is it common practice to have a single file act as a collection for all the other files? E.g. that single file just requires the other files?
So x.lua consists of only require "a" and require "b", for example.
@JosephWright So your chemistry work doesn't involve things like Python or R?
Excel statistical features are pretty sucky. As I recall, they had these glaring bugs, and nobody would fix them.
I remember running into one of them, and the idiot professor I was dealing with suggested (in an email) that it was somehow my fault. Turned out to be an Excel bug.
Of course, things may have improved. That was a long time ago.
@FaheemMitha I only need to do simple regression: I'm more at the 'wet' end of chemistry, so do simple fitting of linear data sets, no global fitting or whatnot
@FaheemMitha Yes, that's not unreasonable
@FaheemMitha Yes, either local function foo() or local foo = function()
@FaheemMitha tables can hold functions as values, which is what I do when writing "modules". My functions are defined as table elements, so I simply export the table afterwards.
@FaheemMitha Did some data analysis a while ago using some big-ish tables. I made the mistake of using multiple sheets: turns out, this means Excel stops using a sparse approach to data storage. Result: massive memory usage, at least for the 32-bit version :(
@PauloCereda Yes, I was considering doing that. Actually, the table I mentioned earlier already contains functions, because those functions share values.
@FaheemMitha -- The city budget is in such bad shape that such things are ignored. Actually, street tree care is handled more carefully by the utilities that are responsible for overhead wires; if they don't take care of regular trimming, weak branches can fall and break the wires during a storm, and that has even more serious consequences.
The memory handling is not especially good, but the same could be said of R.
Actually, R memory handling used to be worse.
@barbarabeeton I always assumed that those small East Coast states were in good shape.
Relatively speaking.
But perhaps that's more a European thing.
Anyway, sorry to hear about your trees.
I actually had to spend some time here trying to get the local municipality to cut the trees here. They were rather overgrown, though otherwise in good shape, as far as I could tell.
Unfortunately, Bombay has the most useless and corrupt municipal corporation on earth. At least, it seems that way sometimes. So it took a while.
Those trees were over 50 ft high and overhanging the terrace. So it was getting a little inconvenient.
I doubt anyone does maintenance aside from that.
I had to write them a letter before they would do anything. In TeX, naturally.
Are there any restrictions on what I can name a file in Lua? For example, would util.lua work? I guess I'd have to avoid keywords, at least.
@FaheemMitha you can I think always refer to it as a string (even if other syntax is available if the name is a valid lua name) similar to table keys you can only use the table.key=3 syntax if key is a valid name, but you always have table["this key ///:"]=3 possibility.
@FaheemMitha -- The smallest one has, unfortunately, some serious problems, although I haven't been affected personally. It's the youngest generation that's being most seriously deprived.
! Package doc Error: Checksum not passed (714<>583).
See the doc package documentation for explanation.
Type H <return> for immediate help.
...
l.823 % \Finale
@UlrikeFischer originally \Finale complained if there was no checksum but some time ago we changed it so it only checks one if it is there and silently skips the check if no checksum is specified.
@DavidCarlisle I added the changes from Frank to hyperref. For me the tests failed in four cases with luatex as for some reason it decided that the Xheight of latin modern is different now. Do you get this failures too?
@PauloCereda (actually that's always a pain: if I need people to write my name correctly I hand them a document. Otherwise I let them do what their imagination allows :-)
@JosephWright If you are doing data analysis, there is something to be said for relational databases. SQLite is very popular, as it is extremely lightweight, but if you want something more serious PG is the way to go. DBs are language agnostic, so it's helpful if you want to switch between different analysis tools. Much better than serialization (ugh).
@StefanKottwitz I hope that the hurricane that was downgraded to force 2 if I remember correctly did not cause excessive damage in your area. my most sincere and welcome greetings.
Though not really an SQL fan, which everyone insists of using. And I think there are better things possible than the standard relational model, but I haven't checked out available options, if any.
And I have my reservations about PG, specifically the query optimizer, which IMO is kind of braindead, but it seems remarkably solid/stable. I never found a PG bug, for example, and I never managed to crash it.
And I run into bugs all the time, all over the place.
@UlrikeFischer you learn something, and it’s funny. but mostly because he keeps insulting his audience, albeit with a glint in his eye. (”you’re too dumb to understand this“.)
@FaheemMitha sqlite is fine even if you’re extremely serious. but if you want multiple writers, postgres is it. the sqlite site has a page dedicated to discussing when you should or should not use sqlite.
@FaheemMitha It was already fun when I was ship crew, working as IT Officer.
@FaheemMitha Now I’m employed by an airline but flying around as consultant engineer for cruise ships of various cruise lines, that’s fun on the fast lane, on speed. A big wage doesn't hurt either.
I try to understand some strange floating mechanism of my figures. Is it correct, that a figure which is too large for a page will float to the end of a chapter, because it is always too large?
@JonasStein You have a bunch of options. Can you make it smaller? If not, you can try to use [h] to start with. I think there are other things you can do too.
And I think removing float is also a possibility.
Normally people here will want a MWE first. Otherwise it will just be general advice.
@FaheemMitha No, a macro expansion text processing language is great for automating network config tasks. Especially if it does the documentation texts and drawings at the same time too.
@FaheemMitha The best way doesn't have to be using the best tool. You cannot invest months in learning a different language because it fits better, than to do it in a language that your team already knows it well, in some hours or days.
@FaheemMitha if the choice is have no backup, tell someone to at least dump a tar file somewhere safe or teach someone how to use git/mercurial/svn/whatever the tar file has lots of advantages.
@FaheemMitha why? I have been doing this with my thesis. Worked pretty well. It has the least overhead for setup, and I only needed it like 20 times. So what's the matter? Right-clicking a folder and clicking "Compress" takes like 3 seconds :)
For things that can evolve over years? That's a different story, and I think I should have set up a version control for some of my sheet music, for instance. However, I still mark the published versions with publish date, and so far this has been sufficient.
@Sebastiano I usually send a photo from the plane with the map on the screen to my girlfriend before it starts. It often contains champagne or sparkling wine as it's often served when you take a seat ;)
