![](\"http://jsonfeed.org/graphics/icon.png\"){kind=icon}
On Wednesday night I know where I’ll be — playing keyboard for a few songs at the James Dempsey and the Breakpoints concert benefitting App Camp for Girls.
\n\nYou should get tickets. It’s a fun time for a great cause.
\n\nBonus: James writes about how this concert is full circle for him. It’s a special night.
", "date_published": "2017-06-02T22:05:47-07:00" }, { "id": "http://inessential.com/2017/06/01/evergreen_diary_1_open_source", "url": "http://inessential.com/2017/06/01/evergreen_diary_1_open_source", "title": "Evergreen Diary #1: Open Source", "content_html": "Evergreen is a new feed reader for Macs. It’s not actually done yet — in fact, it’s not even alpha yet, much less beta. It’s still in the painful-to-use stage, for sure.
\n\nI’ve been working on it (among other things) on nights and weekends for a couple years. For much of the time I planned to make it a for-pay app — the plan was a free Lite version and a for-pay version.
\n\nBut as time went on I was less and less motivated to make a for-pay app. Doing all that stuff — dealing with licenses, money, a store, support, and everything else that goes along with a commercial app — just didn’t sound like any fun, and it would have taken time away from actually working on the app, which is all I really want to do. I just don’t have time to spare.
\n\nSo I decided to make it free and open source. (The code is up on GitHub.) This fits with my goals:
\n\nI like developing in public. Publishing the code makes it feel like a performance, a kind of tightwire act. Which suits me.
\n\n* * *
\n\n\nThe one thing that almost held me back from making it open source was the effect on other developers. There are for-pay Mac feed readers, after all, and I don’t want to take anything away from them.
\n\nAnd I don’t want to send the message that software ought to cost nothing.
\n\nI think that making it open source makes it an obvious special case. There is at least one other open source Mac feed reader, and there are other open source Mac apps, and I don’t think that these projects are fueling the race to the bottom with app pricing.
\n\nI went over and over this decision for months. It wasn’t easy! But in the end I decided it’s a good thing, and there are always good reasons not to do a good thing.
\n\n* * *
\n\n\nThe app doesn’t have any icons yet. Brad Ellis, who I’ve worked with before on some versions of my previous feed reader, and who is my favorite designer, is working on icons.
\n\nBrad is not only my favorite designer, he’s the favorite designer of people who thought they might be my favorite designer. :)
\n\n* * *
\n\n\nAt some point it will sync with some existing systems (such as Feedly, FeedBin, and similar) — but probably not till after 1.0, though as top priority.
\n\nI have no plans to make an iOS version (though anything could happen). The plan is to make it a great Mac app. Period. But if it syncs with Feedly and so on, then you could use some other reader on iOS and it would sync with Evergreen.
\n\n* * *
\n\n\nThere is a road not taken here that’s worth exploring, though probably not by me (for reasons of time).
\n\nI would love to see a casual feed reader (as opposed to productivity-style) that just provides a timeline, with new stuff at the top. The idea is to make something like a Twitter client but for feeds. You’d get a list of articles, and when you want to read something you’d click (or whatever) to open the article in your browser.
\n\nSuch an app wouldn’t have per-article read/unread status — instead it would maintain a high-water mark, the date of the newest item you’ve seen in the timeline.
\n\nFor a little while I was planning to do both styles of reader, since so much of the code would be shared. But that was overly ambitious, so I dropped the idea.
\n\nBut you could do it.
\n\n* * *
\n\n\nI made a Twitter account: evergreen_mac. Though I have no fondness for Twitter, it seems like app makers need to be accessible that way. Most Evergreen users will probably be on Twitter.
\n\nBut you don’t have to use it: you can report bugs and make feature requests via GitHub. And that way they’re in the system, which is good.
\n\nYou can also email me: I’m brent at the domain name that appears in the link that starts the first sentence of this post.
", "date_published": "2017-06-01T17:27:32-07:00" }, { "id": "http://inessential.com/2017/05/26/app_the_human_story_screening_in_san_", "url": "http://inessential.com/2017/05/26/app_the_human_story_screening_in_san_", "title": "“App: The Human Story” Screening in San Jose", "content_html": "Here’s the scoop. It’s Sunday, June 4 at 5 pm. There’s a panel afterward with a bunch of people from the movie (including me).
\n\nYou can get tickets. You should get tickets — the event benefits App Camp for Girls.
\n\nPlus I think you’ll enjoy it. :)
", "date_published": "2017-05-26T12:57:19-07:00" }, { "id": "http://inessential.com/2017/05/17/json_feed", "url": "http://inessential.com/2017/05/17/json_feed", "title": "JSON Feed", "content_html": "I was hesitant, even up to this morning, to publish the JSON Feed spec.
\n\nIf you read Dave Winer’s Rules for standards-makers, you’ll see that we did a decent job with some of the rules — the spec is written in plain English, for example — but a strict application of the rules would have meant not publishing at all, since “Fewer formats is better.”
\n\nI agree completely — but I also believe that developers (particularly Mac and iOS developers, the group I know best) are so loath to work with XML that they won’t even consider building software that needs an XML parser. Which says to me that JSON Feed is needed for the survival of syndication.
\n\nI could be wrong, of course. I admit.
\n\nSee my RSXML repository for Objective-C code that reads RSS, Atom, and OPML. I’ve done the work for you of supporting those formats. Go write a feed reader! Seriously. Do it.
\n\nI planned to have a JSON Feed parser for Swift done for today, but other things got in the way. It’s coming soon. But you probably don’t actually need any sample code, since JSON is so easy to handle.
\n\nFeedback has been interesting so far. Some questions on the GitHub repo need answering.
\n\nSome people have said this should have happened ten years ago, and other people have said that they hate how developers jump on the latest fad (JSON).
\n\nAnd some people really like the icon:
\n\n
One of the more serious criticisms was this: why not just support the hAtom microformat instead? Why do another side-file?
\n\nMy thinking:
\n\nMy experience as a feed reader author tells me that people screw up XML, badly, all the time — and they do even less well with HTML. So embedding info in HTML is just plain too difficult. In practice it would be even buggier than XML-based feeds.
\n\nAnd there are other advantages to decoupling: a side-file can have 100 entries where there are only 10 on an HTML page, for instance. A side-file can have extra information that you wouldn’t put on an HTML page. And yet, despite the extra information, a side-file can be much smaller than an HTML page, and it can often be easier to cache (since it’s not different based on a logged-in user, for instance).
\n\nMicroformats sounds elegant, but I don’t prize elegance as much as I value things that work well.
", "date_published": "2017-05-17T13:22:14-07:00" }, { "id": "http://inessential.com/2017/05/01/frontier_diary_8_when_worlds_collide", "url": "http://inessential.com/2017/05/01/frontier_diary_8_when_worlds_collide", "title": "Frontier Diary #8: When Worlds Collide", "content_html": "I spent the weekend making a bunch of progress on the compiler. It has two pieces: a tokenizer, which I created by rewriting the original C code (langscan.c) in Swift, and a parser.
\n\nThe parser in OrigFrontier was generated by MacYacc, which is similar to Yacc, which is similar to Bison, which is on my Mac. The thing about the parser is that it’s C code, and the rest of the app is Swift.
\n\nHow do you bridge the two worlds? Easy answer: with Objective-C, which is a superset of C and which plays nicely (enough) with Swift.
\n\nSo I renamed langparser.y — the rules file that the parser generator uses — to langparser.ym so that Xcode would know to treat the generated parser source as Objective-C. I edited it slightly, not to change the grammar rules but to change how nodes are created (as return values rather than via inout).
\n\nI also made my CodeTreeNode class, written in Swift, an Objective-C class so that it would be visible to my Objective-C code.
\n\nAnd then, finally, I started a build…
\n\n…and then it stopped with an error because the parser places my CodeTreeNode in a C union, which isn’t allowed in ARC.
Crushed.
\n\n* * *
\n\n\nI think I have three options:
\n\nCodeTreeNode objects, and then disposes the C-struct-node-tree.My thinking:
\n\nI could waste a ton of time on #1, and bending tools in that way can be pretty frustrating work when they refuse to bend.
\n\nWith #2 I’d feel a bit weird about the redundancy: building a tree and then building a copy of that tree with a different type of object.
\n\nMy heart tells me #3 is the answer. After all, I’ve already done the tokenizer. How hard would it be to parse those tokens into a code tree? I could skip C and Objective-C altogether and stay in Swift. And it would be so fun. (Because that’s precisely the style of weirdo I am.)
\n\n* * *
\n\n\nBut the real answer is #2. Writing a parser by hand would take way longer than I think. Given enough tests, it shouldn’t be a huge source of bugs, but still.
\n\nThe thing about #2 is that yes, it’s redundant, it’s doing more work than it needs to, ideally — but my bet is that it would still be so fast that you wouldn’t be able to tell the difference. Computers are so good at this kind of thing. It’s not like reading files or networking; it’s just in-memory traversal and creating/releasing things.
\n\nYou remember in Indiana Jones that guy with the twirling swords, and Indy gives that look and then just shoots him? The second option is the Indiana Jones solution.
\n\nUpdate 2:05 pm: Two people have already written me to recommend ANTLR. So I will definitely give that a look. It might be exactly what I need.
", "date_published": "2017-05-01T13:34:23-07:00" }, { "id": "http://inessential.com/2017/04/27/frontier_diary_7_pretty_much_everythin", "url": "http://inessential.com/2017/04/27/frontier_diary_7_pretty_much_everythin", "title": "Frontier Diary #7: Pretty Much Everything Throws", "content_html": "A script can throw an error, either intentionally (via the scriptError verb) or by doing something, such as referencing an undefined object, that generates an error.
OrigFrontier was written in C, which has no error-throwing mechanism, and so it worked like this: most runtime functions returned a boolean (for success or failure), and the return value was passed in by reference. If there was an error, the function would set a global error variable and return false. The caller would then have to check that global to see if there was an error, and then do the right thing.
\n\nThis was not unreasonable, given the language and the times (early ’90s) and also given the need to be very careful about unwinding memory allocations.
\n\nBut, these days, it seems to me that Swift’s error system is the way to go. There’s just one downside to that, and it’s that I have to do that do/try/catch dance all over the place, since pretty much any runtime function can throw an error.
\n\nEven the coercions can throw, so last night I changed the Value protocol so that asInt and so on are now functions, since properties can’t throw (at least not yet).
The extra housekeeping — the do/try/catch stuff — kind of bugs me, but it’s honest. I considered making script errors just another type of Value — but that meant that all those callers have to check the returned Value to see if it’s an error, and then do the right thing. Better to just use Swift’s error system, because it makes for more consistent code, and it makes sure I’m catching errors in every case.
\n\nIt also means I’m not multiplying entities. A Swift error is a script error, and vice versa.
\n\n* * *
\n\n\nWorking on this code is like applying the last 25 years of programming history all at once.
\n\nA completely different type of error is a bug, and I’m certain to write a bunch of them, because that’s how programming goes.
\n\nThat’s where unit tests come in. Frontier has long had a stress-test suite of scripts — you’d launch the app, run that suite, wait a while, and see if there are any errors. This was critically helpful.
\n\nBut OrigFontier didn’t have unit tests at the C code level. The new version does. (Well, I’ve started them anyway.) This means I can more easily follow Rule 1 — the no-breakage rule — and can also more easily follow Rule 1b — the don’t-break-Dave rule.
\n\nPS I’ve added a collection page for the Frontier Diary, as I did with earlier diaries. There’s a link to it in the footer of every page on the blog.
", "date_published": "2017-04-27T13:30:42-07:00" }, { "id": "http://inessential.com/2017/04/26/frontier_diary_6_ballard_from_the_par", "url": "http://inessential.com/2017/04/26/frontier_diary_6_ballard_from_the_par", "title": "Frontier Diary #6: Ballard, from the Parallel Universe", "content_html": "In another universe I didn’t decide to port Frontier — instead, I started over from scratch on an app inspired by Frontier.
\n\nIn that universe, the new scripting language, descended from UserTalk, is called Ballard. And it’s documented.
", "date_published": "2017-04-26T13:04:04-07:00" }, { "id": "http://inessential.com/2017/04/25/my_microblog", "url": "http://inessential.com/2017/04/25/my_microblog", "title": "My Microblog", "content_html": "I’m on Manton‘s cool new microblogs system. Here’s where you can follow me, once you’re on the system: http://micro.blog/brentsimmons.
\n\nAnd here’s my microblog: http://brent.micro.blog/. (Which you can read using RSS, whether you’re on the system or not.)
\n\nI wrote about three-quarters of my own single-user microblog system — and then stopped because I didn’t feel like running a server and because Manton’s service is so good.
", "date_published": "2017-04-25T14:27:28-07:00" }, { "id": "http://inessential.com/2017/04/25/frontier_diary_5_values_and_progress_o", "url": "http://inessential.com/2017/04/25/frontier_diary_5_values_and_progress_o", "title": "Frontier Diary #5: Values and Progress on the Language", "content_html": "I put the Frontier repository up on GitHub.
\n\n(The build is currently broken. This is bad discipline, but since it’s still just me, I forgive myself. Sometimes I run out of time and I just commit what I have.)
\n\nThe repo has my new code and it also contains FrontierOrigFork, which is the original Frontier source with a bunch of deletions and some changes. The point is to give me 1) code to read and 2) a project that builds and runs on my 10.6.8 virtual machine.
\n\nThe original code is in C, and the port is, at least so far, all in Swift. In the end it should be almost all in Swift, but I anticipate a couple places where I may need to use Objective-C.
\n\nHere’s one of the Swift wins:
\n\nSince Frontier contains a database and scripting language, there’s a need for some kind of value object that could be a boolean, integer, string, date, and so on.
\n\nOriginal Frontier used a tyvaluedata union, with fields for the various types of values.
\n\nThis is a perfectly reasonably approach in C. It’s great because you can pass the same type of value object everywhere.
\n\nWere I writing this in Objective-C, however, I’d create a Value protocol, and then create new value objects for some types and also extend existing objects (NSNumber, NSString, etc.) to conform to the Value protocol. This would still give me the upside — passing a Value type everywhere — while reducing the amount of boxing.
But: this still means I have an NSNumber when I really want a BOOL. Luckily, in Swift I can go one better: I can extend types such as Bool and Int to conform to a Value protocol.
This means passing around an actual Bool rather than a boxed boolean. I like this a ton. It feels totally right.
Other topic:
\n\nI’m still in architectural mode, where I’m writing just enough code to validate and refine my decisions. A couple days ago I started on the language evaluator — the thing that actually runs scripts.
\n\nIt works as you expect: it takes a compiled code tree and recursively evaluates it. It’s not difficult — it’s just that it’s going to end up being a fair amount of code.
\n\nI’ve done just enough to know that I’m on the right path. (The Swift code looks a lot like the C code in OrigFrontier’s langevaluate.c. See evaluateList, for instance.)
The next step is for me to build the parser. I thought about writing a parser by hand, because it sounds like fun, and it would give me some extra control — but, really, it would slow me way down, so forget it.
\n\nOrigFrontier generated its parser by passing a grammar file — langparser.y — to MacYacc (there was such a thing!), which generated langparser.c.
\n\nI’ll do a similar thing, except using Bison (which is compatible with Yacc). Or, possibly, using the Lemon parser generator instead. Either way, I’ll want the generated code to be Objective-C. (Well, mostly C, but with Objective-C objects instead of structs.) (I don’t know of a generator that would create Swift code.)
\n\nThis is completely new territory for me, and is exciting.
\n\n(Almost forgot to mention: I’ll need to write a tokenizer. This means porting langscan.c. I’ll need to do this first, since the parser generator needs it. So this is the real next step.)
", "date_published": "2017-04-25T13:26:33-07:00" }, { "id": "http://inessential.com/2017/04/14/save_300_on_coccoaconf_next_door", "url": "http://inessential.com/2017/04/14/save_300_on_coccoaconf_next_door", "title": "Save $300 on CocoaConf Next Door", "content_html": "My pals at CocoaConf asked me to remind you that the Early Bird sale ends in two weeks for CocoaConf Next Door — the one taking place in San Jose during WWDC.
\n\nI’ll be there. At least in the afternoons.
\n\nCheck out the speakers list. Yummy, chewy, nutty speakers list.
", "date_published": "2017-04-14T13:53:02-07:00" }, { "id": "http://inessential.com/2017/04/14/frontier_diary_4_the_quickdraw_problem", "url": "http://inessential.com/2017/04/14/frontier_diary_4_the_quickdraw_problem", "title": "Frontier Diary #4: The QuickDraw Problem and Where It Led Me", "content_html": "In my fork of Frontier there are still over 600 deprecation warnings. A whole bunch of these are due to QuickDraw calls.
\n\nFor those who don’t know: QuickDraw was how, in the old days, you drew things to the Mac’s screen. It was amazing for its time and pretty easy to work with. Functions included things like MoveTo, LineTo, DrawLine, FrameOval, and so on. All pretty straightforward.
These days we have Core Graphics instead, and we have higher-level things like NSBezierPath. QuickDraw was simpler — though yes, sure, that was partly because it did less.
* * *
\n\n\nI was looking at all these deprecation warnings for QuickDraw functions and wondering how I’m ever going to get through them.
\n\nI could, after all, convert all or most of them to the equivalent Core Graphics thing. But sheesh, what a bunch of work.
\n\nAnd, in the end, it would still be a Carbon app, but with modern drawing.
\n\n* * *
\n\n\nSo I thought about it from another angle. The goal is to get to the point where it’s a 64-bit Cocoa app. All these QuickDraw calls are in the service of UI — so why not just start over with a Cocoa UI?
\n\nThe app has some outlines (database browser, script editor, etc.), a basic text editor, and a handful of small dialogs. And all of that is super-easy in Cocoa.
\n\nUse an NSOutlineView, NSTextView, and some xibs for the dialogs, and we’re done. (Well, after some work, but not nearly the same amount of work as actually writing an outliner from scratch.)
In other words, instead of going from the bottom up — porting the existing source code — I decided to start from the top down.
\n\nI started a new workspace and started a new Frontier project: a Cocoa app with Swift as the default language.
\n\nThen I looked at the existing source and thought about how to organize things. I came up with this:
\n\nI like using frameworks, because it helps enforce separation, and it helps in doing unit testing. And frameworks are so easy with Swift these days.
\n\nHardly any of this is filled-in yet. I’ve got the barest start on FrontierVerbs. Ted Howard, my partner in all this, is taking UserTalk.framework and FrontierDB.framework.
\n\nIn the end, it’s possible that no code from the original code base survives. Which is totally fine. But it also means that this is no quick project.
\n\nAt this point I should probably put it up on GitHub, since it’s easier to write about it if I can link to the code. I’ll do that soon, possibly on the weekend.
", "date_published": "2017-04-14T13:14:20-07:00" }, { "id": "http://inessential.com/2017/04/13/frontier_diary_3_built-in_verbs_config", "url": "http://inessential.com/2017/04/13/frontier_diary_3_built-in_verbs_config", "title": "Frontier Diary #3: Built-in Verbs Configuration", "content_html": "Frontier’s standard library is known as its built-in verbs. There are a number of different tables: file, clock, xml, and so on. Each contains a number of verbs: file.readWholeFile, clock.now, and so on.
Most of these verbs are implemented in C, in the kernel, rather than as scripts. At the moment, to add one of these kernel verbs, you have to jump through a few hoops: edit a resource, add an integer ID, add to a switch statement, etc. It’s a pain and is error-prone.
\n\nSo I want to re-do this in Swift, because I’m all about Swift. And I want adding verbs to be fool-proof: I don’t want to remember how to configure this every single time I add a verb. Adding a verb needs to be easy.
\n\nMy thinking:
\n\nTo make things easy and obvious, I think it should work like this: the selector for a given verb is its name plus a parameter. Then there’s not even a lookup step.
\n\nEach verb will take a VerbParameters object and return a VerbResult object.
\n\ndynamic func readWholeFile(_ params: VerbParameters) -> VerbResult\nThe flow goes like this:
\n\nfile.readWholeFile.file suffix and so we know we need a FileVerbs object.fileVerbs.supportedVerbs (an array) to see if readWholeFile is in the list. It is.readWholeFile part of the string and we add a : character: NSSelectorFromString(verbName + \":\")This is great! We’re almost home free. Then we run the verb:
\n\nif let result = perform(selector, with: params) as? VerbResult {\n return result\n}\nThat doesn’t work. We get:
\n\nCast from 'Unmanaged<AnyObject>! to unrelated type 'VerbResult' always fails\nNuts.
\n\n* * *
\n\n\nIt was so close.
\n\nIn Objective-C this would have worked. And obviously, apparently, I still think in Objective-C.
\n\nI investigated some other options. At one point enums were abused, because there’s always, in Swift, an enum-abuse step. But everything I tried was more code and was more error-prone, and my goal here is to improve the situation.
\n\nI think, in the end, I’m going to do something that looks kind of ugly: a switch statement where the cases are string literals.
\n\nswitch(verbName) {\ncase \"readWholeFile\":\n return readWholeFile(params)\n…\n}\n“Nooooo!” you cry. I hear ya.
\n\nMy experience as an object-oriented programmer tells me this: if I write a switch statement, I blew it.
And my experience as a programmer tells me that string literals are a bad idea.
\n\nBut the above may actually be the easiest to configure and maintain. Each string literal appears only in that one switch statement and nowhere else in the code. And the mapping between a verb name and its function couldn’t be more clear — it’s right there.
\n\n(Yes, instead of using a string literal, I could create a String enum and switch on that. But that’s actually more code and more room for error. I’m going to have to type those string literals somewhere, so why not right where they’re used?)
\n\nIt does mean that readWholeFile appears three times in the code (the string literal, the call, and the function itself), and in an Objective-C version it would appear only twice (in a supportedVerbs array and the method itself).
But. Well.
\n\nI’m torn between shuddering in abject and complete horror at this solution and thinking, “Hey, that’s pretty straightforward. Anybody could read it. Anybody could edit it.” Which was the plan all along.
\n\nAnd I get to stick with Swift, so there’s that.
\n\nBut, sure as shootin’, some day someone’s going to come across this code and say, “Brent, dude, are ya new?” And I’ll send them the link to this page.
\n\n* * *
\n\n\nUpdate the next day: well, the performSelector thing would work, if only I’d known about Swift Unmanaged objects.
Joe Groff told me how this works.
\n\nHere’s the gist: the Unmanaged<AnyObject> just needs to be unwrapped by calling takeRetainedValue or takeUnretainedValue. Once unwrapped, it can be cast to VerbResult.
All this means that I can use my original design, which is great news.
\n\n* * *
\n\n\nUpdate April 25, 2017: I ended up using enums after all. See MathVerbs.swift for an example.
", "date_published": "2017-04-13T22:25:41-07:00" }, { "id": "http://inessential.com/2017/04/11/frontier_diary_2_two_good_ideas_that_a", "url": "http://inessential.com/2017/04/11/frontier_diary_2_two_good_ideas_that_a", "title": "Frontier Diary #2: Two Good Ideas that Aren’t Good Anymore", "content_html": "Strings in Frontier are usually either Pascal strings or Handles.
\n\nYou probably don’t know what I’m talking about. I’ll explain.
\n\nFrontier is a Mac Toolbox app that’s been Carbonized just enough to run on OS X. You may recall that the Mac Toolbox was written so long ago that the original API was in Pascal. That Pascal heritage lived on in many ways, even after everyone switched to C — and one of those ways was Pascal strings.
\n\nA Pascal string is n bytes long, and the first byte specifies the length of the string, which leaves the rest of the bytes for the actual string. Str255 was probably most common, and certainly is most common in Frontier, but there are also smaller sizes: Str63 and Str31, for instance.
Unlike C strings, they’re not zero-terminated, since there’s no need to calculate the length: you always know it from that first byte.
\n\nYou create a literal Pascal string like this…
\n\nStr255 s = \"\\pThis is a string\";\n…and the compiler turns the \\p into the correct length (16 in this case).
Now, I bet you’re saying to yourself, “Self, those Pascal strings are too small to be useful.”
\n\nBut consider this: every menu item name can fit into a Pascal string. You can fit a window title or a file name into a Pascal string (in fact, memory suggests that file names were even shorter, were Str31 Pascal strings). Any label or message on any bit of UI is probably short enough to fit into a Pascal string. (Especially if you assume English.)
So for GUI apps these were terrifically useful, and the 255-byte limit was no problem. (You can fit a tweet in a Pascal string, after all, with a bunch of room left over. [Well, depending on the size of the characters.])
\n\nFrontier still uses them internally a ton. (For some reason, in the Frontier code, Str255 strings are called bigstring, which sounds ironic, since they’re so small, but I think it was to differentiate them from even smaller Pascal strings such as Str31.)
You might ask what the text encoding was for these strings.
\n\n“Text whatzit?” I’d reply. “Oh, I see. Just regular.” (MacRoman.)
\n\nIt was a good idea, but its time has come and gone. We have better strings these days.
\n\nFrontier includes a scripting language and a database, which means it certainly has a need for strings much larger than 255 bytes.
\n\nIt also needs heap storage for other things — binary data, structs, etc. — that could be much larger than 255 bytes.
\n\nEnter the Handle. A Handle points to a pointer that might move: the memory you access via a Handle is relocatable.
\n\nWhich sounds awful, I know, but it was a smart optimization in the days when your Mac’s memory would be a single-digit number of megabytes, or even less than that.
\n\nHere’s the problem: your application’s heap space can become fragmented. It could have a whole bunch of gaps in it after a while. So, to regain that memory, the system could compact the heap — it would remove those gaps, which means relocating the memory pointed to via a Handle.
\n\nThis is better than running out of memory, obviously. But it means that you have to be careful when dereferencing a Handle: you have to actually lock it first — HLock(h) — so that it can’t be moved while you’re using it. (And then you unlock it — HUnlock(h) — when finished.)
Handles are also resizable — SetHandleSize(h, size) — and resizing a Handle can result in it needing to move, if there’s not enough space where it is. Or other Handles might move. You don’t ever know, and don’t care, and you think this is elegant because the system handles it all for you.
All you have to deal with is an additional level of indirection (**h instead of *p), locking and unlocking it when needed, and disposing of it — DisposeHandle(h) — when finished. (No, there’s no reference counting, slacker.)
Nowadays, on OS X, Handles don’t ever move and there’s no heap compaction. So there’s no reason for them whatsoever. And they are, as expected, deprecated.
\n\nNevertheless, Frontier, a Mac Toolbox app written in C, uses Handles everywhere.
\n\n(I remember being shocked, when I first started learning Cocoa 15 years ago, that there were no Handles. It seemed incredibly daring that objects were just pointers. It made me nervous!)
\n\nAlmost all the Mac APIs that Frontier uses are deprecated. That’s one thing.
\n\nBut it’s worse than just that: the ways Frontier handles strings and pretty much every single thing it stores on the heap are also deprecated.
\n\nSo: what to do?
\n\nThe end goal is a Cocoa app, which means I’ll be able to use Foundation, CoreFoundation, and Swift data types: NSString and Swift String, for instance. There are a number of different structs in the code, and those will be turned into Objective-C and Swift objects and Swift structs.
\n\nThe tricky part, though, is getting from here to there. I think the first step is to start with Objective-C and Foundation types and use them where possible. I can do that without actually turning it into a Cocoa app (the app will still have its own WaitNextEvent event loop and Carbon windows) — which means I’ll have to bracket all Objective-C code in autorelease pools, and I’ll have to use manual retains and releases. I’m not sure how far that will get me, but it will get me closer.
\n\nPS Here are a couple articles by Gwynne Raskind on the Mac Toolbox you might enjoy: Friday Q&A 2012-01-13: The Mac Toolbox and The Mac Toolbox: Followup.
", "date_published": "2017-04-11T13:01:55-07:00" }, { "id": "http://inessential.com/2017/04/05/two_little-known_and_completely_unrelate", "url": "http://inessential.com/2017/04/05/two_little-known_and_completely_unrelate", "title": "Two Little-Known and Completely Unrelated Facts", "content_html": "One. OmniOutliner’s outline view is implemented as CALayers rather than as a view with subviews. (I don’t think I’m giving away a trade secret here.)
\n\nTwo. If you eat fenugreek, your armpits will smell like maple syrup.
", "date_published": "2017-04-05T16:57:59-07:00" }, { "id": "http://inessential.com/2017/04/05/ios_javascript_and_object_hierarchies", "url": "http://inessential.com/2017/04/05/ios_javascript_and_object_hierarchies", "title": "iOS, JavaScript, and Object Hierarchies", "content_html": "\n\n", "date_published": "2017-04-05T14:53:01-07:00" }, { "id": "http://inessential.com/2017/04/05/cocoaconf_near_wwdc", "url": "http://inessential.com/2017/04/05/cocoaconf_near_wwdc", "title": "CocoaConf Near WWDC", "content_html": "Given x-callback-url and App URL schemes in general it would be extremely cool to use those to create object hierarchies using JavaScript. Why JavaScript? Well, it’s native to iOS and applications can use the runtime.
There are a bunch of things happening near WWDC this year. Me, I’ll be at CocoaConf Next Door. I’m not preparing a talk, but I’ll probably be on a panel. And hanging out.
\n\nCheck out the speakers list, which includes Omni’s own Liz Marley. And a bunch of other people you totally want to see — Manton Reece, Jean MacDonald, Laura Savino, and plenty more.
\n\nAlso… AltConf and Layers will be near WWDC. If you could be in three places at once, you would. Well, four, including WWDC itself, I suppose. :)
", "date_published": "2017-04-05T14:35:05-07:00" }, { "id": "http://inessential.com/2017/04/05/omnioutliner_5_0_for_mac", "url": "http://inessential.com/2017/04/05/omnioutliner_5_0_for_mac", "title": "OmniOutliner 5.0 for Mac", "content_html": "I’ve been on the OmniOutliner team for over a year now. Though we don’t have positions like junior and senior developer, I enjoy calling myself the junior developer on the Outliner team, since I’m newest.
\n\nI may be a new developer, but I’m not a new user — I’ve been using the app since the days when OmniOutliner 3 came installed on every Mac.
\n\nEvery time I start a talk, I outline it first. I organize the work I need to do in my side-project apps in OmniOutliner. And — don’t tell the OmniFocus guys, who are literally right here — sometimes I even use it for to-do management in general. I’d be lost without a great outliner.
\n\nAnyway… there’s a new version: OmniOutliner 5.0. It’s my first dot-oh release at Omni, and I’m proud of it and proud of the team.
\n\nAs is common with our apps, we have two levels: a regular level and a Pro level. The regular level is called “Essentials” and is just $9.99. There’s a demo so you can try it out first.
\n\nIt syncs with iOS and with other Macs, by the way. Sync is free. And of course it comes with extensive documentation, and Omni’s awesome support humans are standing by.
\n\n", "date_published": "2017-04-05T10:44:45-07:00" }, { "id": "http://inessential.com/2017/04/03/frontier_diary_1_vm_life", "url": "http://inessential.com/2017/04/03/frontier_diary_1_vm_life", "title": "Frontier Diary #1: VM Life", "content_html": "It’s been years since I could build the Frontier kernel — but I finally got it building.
\n\nIt’s really a ’90s Mac app that’s been Carbonized just enough to run on MacOS, but it’s by no means modern: it uses QuickDraw and early Carbon APIs. It’s written entirely in C.
\n\nI got it building by installing MacOS 10.6.8 Server in VMWare. Installed Xcode 3.2.6. And now, finally, I can build and run it.
\n\nFrontier — as some of you know — was a UserLand Software product in the ’90s and 2000s. I worked there for about six years.
\n\nThe app is a development environment and runtime: a persistent, hierarchical database with a scripting language and a GUI for browsing and editing the database and for writing, debugging, and running scripts.
\n\nThe Nerd’s Guide to Frontier gives some idea of what it’s like, though it was written before many of the later advances.
\n\nMaybe you’ve never heard of it. But here’s the thing: it was in Frontier that the following were either invented or popularized and fleshed-out: scripted and templated websites, weblogs, hosted weblogs, web services over http, RSS, RSS readers, and OPML. (And things I’m forgetting.)
\n\nThose innovations were due to the person — Dave Winer — and to the times, the relatively early web days. But they were also in part due to the tool: Frontier was a fantastic tool for implementing and iterating quickly.
\n\nThe high-level goal is to make that tool available again, because I think we need it.
\n\nThe plan is to turn it into a modern Mac app, a 64-bit Cocoa app, and then add new features that make sense these days. (There are so many!) But that first step is a big one.
\n\nThe first part of the first step is simple, and it’s where I am now: mass deletions of code. Every reference to THINK_C and MPWC has to go. All references to the 68K and PPC versions must go. There was a Windows port, and all that code is getting tossed. And then I’ll see the scale of what needs to be done.
\n\n(Note: my repo is a fork, and it’s not even on the web yet. The code I’m deleting is never really gone.)
\n\nI’m doing a blog diary on it because it helps keep me focused. Otherwise I’m jumping around on my side projects. But if I have to write about it, then I’ll stay on target.
", "date_published": "2017-04-03T13:44:34-07:00" }, { "id": "http://inessential.com/2017/03/31/the_goal", "url": "http://inessential.com/2017/03/31/the_goal", "title": "The Goal", "content_html": "The goal isn’t specifically impeachment and conviction. It’s for Trump to leave office.
\n\nThe stretch goal is that he dies broke and in prison.
\n\nBut we could settle for him going down in history as our worst President, as the worst person ever to become President, with the name Trump held in less esteem than that of Benedict Arnold, with Trumpism — that pseudo-populist white nationalism for the benefit of the super-rich — thoroughly loathed and seen for the brutish scam that it is.
\n\nI think there comes a point before an actual trial in the Senate where Republican leaders — in Congress, in the Cabinet, wherever — realize that Trump can no longer govern, and they tell him so and urge him to resign.
\n\nAnd I think he actually does resign at that point. He’s been through bankruptcy, and he’s shown that when there’s no path to winning, he’ll take the easiest route out of the situation, the route that leaves him the most status. He doesn’t have the stick-to-it-iveness to go to trial in the Senate: he’d quit.
\n\nI don’t know what it will take to bring Republican leaders to this point. Their ongoing cowardice is the real scandal — when faced with a threat to our democracy, they play along because they’re hoping for some goodies.
\n\nI don’t think they get to this point unless the public gets to this point, and so I look to the approval polls. If it gets below 30%, it’s probably there because of further revelations in the Russia affair, and it’s probably at the point where even cowards feel safe in doing the right thing — even if only to save their own necks, which will need saving.
\n\nBut right now Speaker Ryan won’t even replace Devin Nunes as chair of the house intelligence committee. So there’s still a long way to go.
", "date_published": "2017-03-31T13:47:44-07:00" }, { "id": "http://inessential.com/2017/03/25/my_cocoaconf_yosemite_2017_talk", "url": "http://inessential.com/2017/03/25/my_cocoaconf_yosemite_2017_talk", "title": "My CocoaConf Yosemite 2017 Talk", "content_html": "Yosemite 2017 was so great. It always is.
\n\nBelow is the rough draft of my first-night talk. A few notes…
\n\nThe actual spoken version is probably not even close to the text, which was written before any rehearsal, and of course it’s never my intent to memorize it exactly.
\n\nThe bit with Laura Savino was a quick three-chord rock medley. We both played acoustic guitar and sang. It went like this:
\n\nB: Louie Louie, oh baby, we gotta go
\nL: Yeah yeah yeah yeah yeah
\nB: Louie Louie, oh baby, we gotta go
\nL: Yeah yeah yeah yeah yeah
\nB: I live on an apartment on the 99th floor of my block
\nL: Hang on Sloopy, Sloopy hang on
\nB: I look out my window imagining the world has stopped\nL: Hang on Sloopy, Sloopy hang on
\n[Slight change of chords]
\nB & L: Teenage wasteland, oh yeah, only teenage wasteland [repeated]
Here’s my favorite video for Brimful of Asha.
\n\nDuring the Squirrel Picture interlude (slide #3) I told the Squirrel Story, which wasn’t planned or recently rehearsed, but I’ve told it often enough that it didn’t really need rehearsal.
\n\nI dedicated the performance of Hallelujah to Dori Smith.
\n\nThe talk was meant to be about 20 minutes long. Afterward I went around the room with a microphone and each person introduced themselves. (The talk’s job is to be a first-night ice-breaker talk.)
\n\nI spent about 10 hours on rehearsal for those 20 minutes.
\n\nHere’s the talk:
\n\nHi. I’m Brent.
\n\nBefore I get started — seeing my friend Brad Ellis reminded me of the most rock-n-roll moment of my life. Where’s Brad? Hi Brad. Anyway — I was at a party at my friend Chris’s house, and he let me borrow his guitar and do a sing-along. I think we did White Rabbit and Me and Bobby McGee and Hotel California.
\n\nWell, here’s the problem — I have a hard time hanging on to a guitar pick. Especially after a few beers. So at one point the pick goes flying, and I’m strumming with my fingers.
\n\nBut I had a hangnail, and it got a bit aggravated as I was strumming. At the end I noticed that there was my actual blood on the guitar. I felt bad about it, but Chris was gracious, of course, and I thought that right then: that’s rock and roll.
\n\nYou can use this as metaphor. Bleeding? Keep right on playing. Maybe you won’t even notice that you’re bleeding, at least not until you stop.
\n\nChris told me later that the guitar cleaned up fine, so all was well.
\n\nOkay. On to the actual talk…
\n\nI bet most of you have heard the phrase “three chord rock n roll.” Or have heard that “rock is so great because you only need three chords.”
\n\nWhat you may not realize is that it’s even easier than that: it’s three specific chords. Always the same three chords.
\n\nThey might be in any key but they’re the first, fourth, and fifth. In the key of C, the first is C, the fourth is F, and the fifth is G. In the key of A it’s A, D, and E.
\n\nAnd when a song does have more than those three chords, it has at least those three chords. They’re the foundation for almost all pop and rock.
\n\nOne part of music is building tension and then resolving it. I’ll demonstrate on guitar.
\n\n[On guitar] Play the first .... and you’re fine. You’re home. Play the fourth .... and there’s a little tension. Not a ton, but some. But you want to go back to the first, to home.
\n\nThen play the fifth ... and you have maximum tension. You definitely want to go back home to the first.
\n\nSo with those three chords you have everything you need to write a thousand songs.
\n\nNow for a little demo, I’d like to invite Laura Savino up to help me out.
\n\n[music]
\n\nThanks, Laura!
\n\nSO LET ME MAKE TWO POINTS VERY CLEAR.
\n\nONE. If you’re writing apps or a website or doing a podcast or whatever — if you’re just starting out and only know the equivalent of three chords, don’t worry — you can create a masterpiece with just three chords.
TWO. If you do know more than three chords, you might want to consider just using those three chords anyway. People love those three chords. They’re appealing. They’re accessible and intimate. They work.
One of my personal favorite three-chord-rock songs came out in the mid-90s. Brimful of Asha by Cornershop.
\n\nWho here knows this song?
\n\nLet me explain what it’s about:
\n\nAsha Bhosle sang songs for Bollywood musicals. The actresses would lip-sync, but it was her singing. She did this for over a thousand movies. Over 12,000 songs.
\n\nSome of those songs would be released as singles. Years ago a single would come out on vinyl, as a 45. A 45 is smaller than a regular album, and it has one song on each side. The number 45 means 45 revolutions-per-minute — you’d have to set your turntable to 45 instead of the usual 33 1/3. So: a 45 is a single.
\n\nSo here’s a little bit from the song:
\n\n[There’s dancing, behind movie screens…]
\n\nI love that image. That Asha is not just singing but dancing as she’s singing. We never see her dancing, but that joy and engagement shows up in her performance.
\n\nAnd so this song is about hope. It’s about how a song can bring some consolation and hope when people need it.
\n\nAnd her name Asha actually means hope. Brimful of Asha — brimful of hope.
\n\nHERE’S MY POINT.
\n\nWe're in the same business. People form an emotional connection to whatever we’re making. The things we make can bring hope to other people. Knowing that, it’s our job to be as engaged and joyful as she is as we make our things. Maybe we’re not literally dancing, but it should be the metaphorical equivalent.
\n\nSquirrel!
\n\nWhen I was a kid we went to a Methodist church. I haven’t been to church hardly at all since I was a kid, but I remember one cool thing from church services: the minister would pause and ask people to shake hands with the people around them.
\n\nSo here are the rules. Tell people to have a good conference, and shake hands with at least one person from another table. Stand up!
\n\nA few weeks ago I found myself in a hotel bar with a bunch of other nerds. I also found a piano. If there’s a piano, I’m going to play it. So I talked a few people — James Dempsey, Jean McDonald, Curt Clifton, and Jim Correia, into singing some songs.
\n\nI forget who suggested Hallelujah. Might have been James. I didn’t know it very well, but I did my best. James sang, and he was awesome.
\n\nSo when I was thinking about this talk, I was thinking of doing the most beautiful possible thing I could do. So I remembered James singing this song.
\n\nI may not be religious, but I think it’s plain that there is awesome magnificence greater than anything any human could make. It’s right outside.
\n\nI’m not sure bears feel humble at the sight of these mountains; I’m not sure birds are awed at the vistas they fly over.
\n\nBut we do. Humans do. And knowing that we can’t measure up, it doesn’t stop us. Intead, we’re inspired.
\n\nSo here’s what I love about Hallelujah. It’s about trying and failing, and loving and losing — and singing Hallelujah anyway. In Cohen’s words, it may be a broken Hallelujah, but it’s still on our lips.
\n\nJames Dempsey please report to the stage.
\n\nEverybody is encouraged to sing along. Especially to the chorus.
\n\n[Hallelujah]
\n\nI’m going to go around the room and have everyone introduce themselves. RULE: if anyone can’t hear, yell out.
", "date_published": "2017-03-25T11:55:21-07:00" } ] }