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Talk:1313: Regex Golf

2015-09-05T17:57:39Z

108.162.212.51:

This is fairly simple fun little one.

Regex is sort for regular expressions. A regular expression is a series of characters that denotes a search criteria. For example, you could write a regular expression that would search for anything that looks like an address (a la [http://www.xkcd.com/208/ comic 208]).

Regex golf is a game in which you attempt to write a regular expression that will search through a list of items and bring back only those items that meet a certain criteria, but not anything else. The joke is that regular expressions are used to search text, but themselves are text strings. This means that you could write a regular expression that would look for another regular expression. You can then apply ''ad infinitum'', and the universe implodes or something.

--[[User:Holshy|Holshy]] ([[User talk:Holshy|talk]]) 05:40, 6 January 2014 (UTC)

The last panel includes, of course, a regex "/(meta-)*regex golf/," which represents the phrase "regex golf" preceded by the phrase "meta-" up to ''infinite'' times.

As a punchline, it also refers to Jamie Zawinski's well-known quote about regex,

<blockquote>Some people, when confronted with a problem, think "I know, I'll use regular expressions." Now they have two problems.</blockquote>

Thus, the punchline is that the addition of meta layers to regex golf generates more problems for the programmer, but that was also the setup of the comic. So either the punchline is really weak—worth a chuckle if you got the above two references—or I missed the joke.
[[Special:Contributions/199.27.128.63|199.27.128.63]] 06:22, 6 January 2014 (UTC)

Could anybody comment on the first regex? Do I get it right that
beyond others it will match all strings that contain a "b"? I can hardly believe that is not the case for any star trek subtitle... [[Special:Contributions/173.245.53.194|173.245.53.194]] 06:54, 6 January 2014 (UTC)
:This is the case for all Star Trek Subtitles. Wikipedia's list of movies had no b. It'll match anything containing a word ending in ''m'', any word beginning with ''n'' or ''t'' that is not the first word, or any word with a ''b''. No Trek movies match. Oddly, so far as I can figure out, the regex in the first panel is wrong, in that it doesn't match the second Star Wars movie at all. And before you tell me prequels don't count, the sole purpose of "m " is to match The Phanto''m ''Menace.[[Special:Contributions/199.27.128.138|199.27.128.138]] 07:10, 6 January 2014 (UTC)
Attack of[ t]he Clones (to be read plainly, not as a regular expression). [[Special:Contributions/173.245.53.107|173.245.53.107]] 07:29, 6 January 2014 (UTC)
:Ah, I thought it was ''The Clone Wars''. [[Special:Contributions/199.27.128.138|199.27.128.138]] 15:36, 6 January 2014 (UTC)
So, if I add an "e" to the "tn" and delete the "|b" I'm a better golf player than her? [[Special:Contributions/108.162.212.194|108.162.212.194]] 08:23, 6 January 2014 (UTC)
:Or you could just move the "b" into the "tn" group. --11:08, 6 January 2014 (UTC)

I got a sneak preview of this comic at about 6:34 EST...at first it appeared to be random text in a irc message, but with this comic it now makes sense to me. [[User:Verticalbar|Verticalbar]] ([[User talk:Verticalbar|talk]]) 09:31, 6 January 2014 (UTC)

'''Regex golf''' (c.f. {{w|Perl golf}}) is a programming competition / is a pastime of finding regular expression that matches one set of strings while matching none of the other set. See for example http://regex.alf.nu --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 11:03, 6 January 2014 (UTC)

The title text isn't exactly true... I haven't tried everything, but that regex doesn't match "gerald ford" at all. [[Special:Contributions/199.27.128.109|199.27.128.109]] 11:23, 6 January 2014 (UTC)
: Gerald Ford wasn't elected, he became President following Nixon's resignation.
[[Special:Contributions/173.245.52.209|173.245.52.209]] 12:12, 6 January 2014 (UTC)

Inspired by regex.alf.nu, a reader built a page where the objective is to make a regular expression to match all Star Wars and no Star Trek: http://zegnat.github.io/xkcd1313/. [[Special:Contributions/173.245.53.127|173.245.53.127]] 14:00, 6 January 2014 (UTC)

I added a list of all US elected presidents and the part of the title regex they match. I used a python script to generate it, with input from [http://http://en.wikipedia.org/wiki/List_of_United_States_presidential_candidates here], then I removed all presidents that do not match after finding they really weren't elected. There may still be superflous ones, that weren't elected but do match the regex, please check. [[Special:Contributions/173.245.49.64|173.245.49.64]] 14:29, 6 January 2014 (UTC)

Does anyone understand the final "No, I had those already"? Is it a reference to regexes in some way or could it be something like that there are infinite problems in life, even when not doing (Meta-)*-Regexes? --[[Special:Contributions/173.245.53.199|173.245.53.199]] 20:32, 6 January 2014 (UTC)

According to Peter Norvig (Director of research at google), one of the Regular Expression of Randall is wrong as demonstrated here : http://nbviewer.ipython.org/url/norvig.com/ipython/xkcd1313.ipynb [[User:Mbussonn|Mbussonn]] ([[User talk:Mbussonn|talk]]) 20:47, 6 January 2014 (UTC)
: It's happening. --[[Special:Contributions/173.245.53.153|173.245.53.153]] 11:39, 7 January 2014 (UTC)

"No one wins at [^ ]+ golf." [[Special:Contributions/141.101.98.209|141.101.98.209]] 09:50, 7 January 2014 (UTC)
: Gee, would that be "No one wins at \S+ golf."? [[User:IronyChef|IronyChef]] ([[User talk:IronyChef|talk]]) 23:57, 9 January 2014 (UTC)

Why does this say that it is Case Sensitive. As far as I can tell it would not work if that were true.[[Special:Contributions/108.162.219.59|108.162.219.59]] 02:28, 7 February 2014 (UTC)

"Note that if one included the animated film “Star Wars: The Clone Wars” it would be matched by “ [tn]”."
- I don't see how this is true, since the T is at the beginning of the subtitle. If this matched, then surely so would all of the original series Star Trek films. {{unsigned ip|141.101.99.41}}

"I got infinite problems and a bitch ain,t one" 15:50, 29 August 2014 (UTC) {{unsigned ip|173.245.56.191}}

Looks like the algorithm is a bit outdated. It fails to match {{w|Star Wars: The Force Awakens|The Force Awakens}} but matches {{w|Star Trek Beyond|Beyond}}--[[Special:Contributions/108.162.212.51|108.162.212.51]] 17:57, 5 September 2015 (UTC)

Talk:1090: Formal Languages

2014-04-10T03:35:31Z

108.162.212.51: /* Grammar vs Language */

==Where to dicuss (moved from article body)==
Maybe the word "Grammar" is just supposed to sound like "Ta-Da" (as in the fanfare sound made in circuses). Which - as odd as this is going to sound - is somewhat similar to how grammar is used in formal languages.

Is it possible that the word crash is some sort of play on the computer term 'crash'? I know that formal linguistics is important to computer science... Just throwing that out there.

You know, either:

a) I'm REALLY dumb (98% probability) and I simply can't find the comments on this comic (or any other for that matter now "it's come to this" (the Wiki). Or...

b) (2% probablity) nobody else has managed to work out how to comment yet either. Is this the way to do it? (seems logical) or is option a) corect? In which case, can someone give me a Noddy's Guide to how to find the comments and add them, please?
(Obviously kindly delete this if option a) is indeed correct!) Steve B. -- ''The explaination is up now. Basically it's a big play on the words 'context free grammar' ''

If only there were some sort of Discussion page where comics could be discussed. There could be a convenient link at the top of the page right next to a link back to the comic page itself. Maybe it could be colored red to stand out from the rest of the page. ''-- It's a blue button next to "Prev"''

==Formal Language==
Because the conference heading implies it is about formal programming languages.
Grammar is about the correct for of language and it's formality and rules (which I break all the time).
It's a pun.
[[Special:Contributions/202.167.15.165|202.167.15.165]] 06:21, 21 November 2012 (UTC)beany
:Formal language is a much broader concept than just programming languages. [[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 15:37, 23 November 2012 (UTC)

==Formal Language==
I'm thinking the page needs a brief description of what a "formal language" is. I linked to the wikipedia article on formal languages, but we should probably add a summary relevant to the comic here. --[[User:DanB|DanB]] ([[User talk:DanB|talk]]) 10:39, 3 August 2012 (EDT)

^
|
'''"Formal languages"''' in a formal language, is '''"Formal languages"'''.

==Norvig vs. Chomsky==
It may be related to this news: http://www.tor.com/blogs/2011/06/norvig-vs-chomsky-and-the-fight-for-the-future-of-ai

==Grammar vs Language==
The pun seems clearly to be related to the difference between a formal language and a formal grammar. A language X is the set of all it's valid statements. On the other hand, a grammar for a language X is a description that can be used produce every single valid statement in the language X, even if it's a language with infinite valid statements. So him shouting "''GRAMMAR''" in a formal ''languages'' forum is most likely meant to be as if he said in a shorthand way everything there was to be said about (the) language.

Talk:1090: Formal Languages

2014-04-10T03:31:48Z

108.162.212.51:

==Where to dicuss (moved from article body)==
Maybe the word "Grammar" is just supposed to sound like "Ta-Da" (as in the fanfare sound made in circuses). Which - as odd as this is going to sound - is somewhat similar to how grammar is used in formal languages.

Is it possible that the word crash is some sort of play on the computer term 'crash'? I know that formal linguistics is important to computer science... Just throwing that out there.

You know, either:

a) I'm REALLY dumb (98% probability) and I simply can't find the comments on this comic (or any other for that matter now "it's come to this" (the Wiki). Or...

b) (2% probablity) nobody else has managed to work out how to comment yet either. Is this the way to do it? (seems logical) or is option a) corect? In which case, can someone give me a Noddy's Guide to how to find the comments and add them, please?
(Obviously kindly delete this if option a) is indeed correct!) Steve B. -- ''The explaination is up now. Basically it's a big play on the words 'context free grammar' ''

If only there were some sort of Discussion page where comics could be discussed. There could be a convenient link at the top of the page right next to a link back to the comic page itself. Maybe it could be colored red to stand out from the rest of the page. ''-- It's a blue button next to "Prev"''

==Formal Language==
Because the conference heading implies it is about formal programming languages.
Grammar is about the correct for of language and it's formality and rules (which I break all the time).
It's a pun.
[[Special:Contributions/202.167.15.165|202.167.15.165]] 06:21, 21 November 2012 (UTC)beany
:Formal language is a much broader concept than just programming languages. [[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 15:37, 23 November 2012 (UTC)

==Formal Language==
I'm thinking the page needs a brief description of what a "formal language" is. I linked to the wikipedia article on formal languages, but we should probably add a summary relevant to the comic here. --[[User:DanB|DanB]] ([[User talk:DanB|talk]]) 10:39, 3 August 2012 (EDT)

^
|
'''"Formal languages"''' in a formal language, is '''"Formal languages"'''.

==Norvig vs. Chomsky==
It may be related to this news: http://www.tor.com/blogs/2011/06/norvig-vs-chomsky-and-the-fight-for-the-future-of-ai

==Grammar vs Language==
The pun seems clearly to be related to the difference between a formal language and a formal grammar. A grammar for a language X can produce all valid statements in the language X, so a finite grammar can even produce an infinite language. So him shouting "GRAMMAR" in a formal "LANGUAGES" forum is most likely meant to be as if he said in a shorthand way everything there was to be said about (the) language.