path: root/2023/info/overlay-after.md

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# Transcript


[[!template new="1" text="""Introduction""" start="00:00:00.000" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Hi, I'm Jeff Trull, and today I'm going to talk to you""" start="00:00:00.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""about improving C++ compiler diagnostics""" start="00:00:04.898" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""using overlays and other features from Emacs.""" start="00:00:08.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""First an overview of my talk.""" start="00:00:13.600" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I'm going to cover what overlays are""" start="00:00:15.840" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and how you can use them in code,""" start="00:00:17.657" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""then I'm going to talk about C++""" start="00:00:19.326" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and why its compiler errors can be so onerous.""" start="00:00:21.479" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Finally, we'll take that information""" start="00:00:24.480" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and build a new minor mode""" start="00:00:26.751" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""using overlays and other Emacs features.""" start="00:00:28.448" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Overlays and what they can do""" start="00:00:33.560" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""First of all, overlays.""" start="00:00:33.560" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""What are they?""" start="00:00:35.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""They are objects consisting of a buffer range""" start="00:00:36.680" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and a set of properties.""" start="00:00:39.125" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""That means that they cover a region in a buffer.""" start="00:00:40.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The properties can be a certain set""" start="00:00:43.120" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""of special property names,""" start="00:00:45.534" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""in which case they can be used to cause""" start="00:00:47.345" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""special effects in the buffer,""" start="00:00:50.289" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but they never change the underlying text.""" start="00:00:52.570" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""You can use them for things like hiding things.""" start="00:00:55.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So, for example, overlays are working right now""" start="00:00:59.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""in this window. `org-present`,""" start="00:01:02.887" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the technology I'm using for this presentation,""" start="00:01:04.661" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""is hiding the asterisk before every headline,""" start="00:01:07.596" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""as well as the things called emphasis markers;""" start="00:01:10.032" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that is, those things that make things look""" start="00:01:12.521" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""monospaced for verbatim, or italic, or bold.""" start="00:01:16.270" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The special characters we use to mark off those sections""" start="00:01:20.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""are also hidden by `org-present` using overlays.""" start="00:01:24.422" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""But those things are still in the buffer""" start="00:01:28.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and they're still visible to code.""" start="00:01:30.602" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So if I run this little snippet of code down here,""" start="00:01:31.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it's going to go up to the headline &quot;Overlays""" start="00:01:34.922" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and what they can do,&quot; and it's going to tell us""" start="00:01:37.404" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""what's there in the buffer.""" start="00:01:40.052" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's go down and run this.""" start="00:01:41.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So according to this code, the contents of the buffer""" start="00:01:45.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to the left of the headline is a star in a space,""" start="00:01:48.958" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which means that even though we can't see that star,""" start="00:01:51.991" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it's still there, because it's hidden by an overlay.""" start="00:01:55.205" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And that's kind of the essence of what overlays are.""" start="00:01:58.220" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Simple overlay example - creating an overlay""" start="00:02:02.500" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Let's do a simple overlay example.""" start="00:02:02.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We have some text on the right here,""" start="00:02:04.780" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which is a famous poem by William Carlos Williams,""" start="00:02:06.720" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which has been the subject of many memes.""" start="00:02:09.340" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's create an overlay that covers it.""" start="00:02:12.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I'll go down here and use this snippet of code here.""" start="00:02:17.860" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We'll go up to the top, and we'll mark everything""" start="00:02:20.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""between `#+BEGIN_VERSE` and `#+END_VERSE`.""" start="00:02:25.919" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""You can see we've created an overlay""" start="00:02:29.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""from position 74 to 224.""" start="00:02:33.277" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Adding properties""" start="00:02:35.700" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Now we can take that overlay that we already created""" start="00:02:35.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and add a property, in this case a `face` property,""" start="00:02:38.064" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to change the appearance of the text.""" start="00:02:41.212" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""This is a poem, and it's currently using""" start="00:02:43.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""a face that is monospaced,""" start="00:02:46.280" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and so it looks like a computer program,""" start="00:02:48.084" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""even though it's a poem.""" start="00:02:50.492" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I think it would be nicer to use something""" start="00:02:51.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with variable-width font, maybe with some serifs.""" start="00:02:54.586" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So let's give that a try.""" start="00:02:57.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now you can see that the poem looks quite a bit different.""" start="00:03:01.140" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It looks more like what we'd see in a book.""" start="00:03:03.700" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Deleting an overlay""" start="00:03:10.940" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""We can also delete overlays.""" start="00:03:10.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So I've named this one.""" start="00:03:13.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So we can just go down and run `delete-overlay`""" start="00:03:15.140" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and get rid of it, and it'll go back to""" start="00:03:17.766" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the appearance it had before.""" start="00:03:20.049" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And there it is.""" start="00:03:22.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It's back to normal.""" start="00:03:23.660" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Setting fonts the right way""" start="00:03:24.660" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Now, if you're interested in changing all of the verses""" start="00:03:24.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""inside an Org Mode file to a different face""" start="00:03:28.474" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or a different font family,""" start="00:03:31.109" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""this isn't the way you'd really do it.""" start="00:03:32.786" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I'll just show you that real quick.""" start="00:03:35.060" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The right way is probably to change the `org-verse` face,""" start="00:03:37.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which is the face used for all of the verse blocks""" start="00:03:43.472" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""inside your Org Mode file.""" start="00:03:48.869" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And so this is how you do it here:""" start="00:03:51.620" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""`face-remap-add-relative`.""" start="00:03:55.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's give it a try.""" start="00:03:56.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It worked!""" start="00:03:58.340" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""More properties""" start="00:03:59.540" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""There are more advanced things that you can do""" start="00:03:59.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""other than just changing fonts.""" start="00:04:01.806" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There's a whole long list of them in the manual,""" start="00:04:03.300" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but let's talk about the ones we're going to use today.""" start="00:04:05.544" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Visibility""" start="00:04:12.580" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""You can make text invisible, just like `org-present` did.""" start="00:04:12.580" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The simplest way is to set the `invisible` property to true,""" start="00:04:17.380" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""so here's a code snippet that will do that.""" start="00:04:21.820" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""What we're going to do is""" start="00:04:24.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""go and find the word &quot;plums&quot; inside the poem,""" start="00:04:26.160" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and then we're going to make it invisible""" start="00:04:28.967" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""by creating an overlay that covers it,""" start="00:04:31.285" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and then setting the invisible property to true.""" start="00:04:33.437" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Boom!""" start="00:04:36.820" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It's gone.""" start="00:04:37.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We've eaten the plums.""" start="00:04:38.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Visibility is a huge topic and very complicated.""" start="00:04:39.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There are powerful mechanisms for using it.""" start="00:04:42.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I suggest reading the manual""" start="00:04:44.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""if you'd like to know more about that.""" start="00:04:46.627" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Adding text""" start="00:04:49.780" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Another thing we can do with properties""" start="00:04:49.780" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""is to add text either before or after an overlay.""" start="00:04:52.118" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Since we've made the word &quot;plums&quot; invisible,""" start="00:04:54.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or anything that you make invisible in the buffer,""" start="00:04:57.348" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""if you add text then afterwards,""" start="00:05:00.575" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it looks like you've replaced the original words""" start="00:05:02.663" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with new words.""" start="00:05:05.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So let's add a property, a `before-string` property,""" start="00:05:08.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to the overlay that we used before""" start="00:05:12.047" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to make it seem as though we're eating cherries""" start="00:05:14.194" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""instead of plums.""" start="00:05:17.138" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Boom!""" start="00:05:18.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There it is.""" start="00:05:19.580" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So that's how you can replace words using overlays.""" start="00:05:22.020" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Custom properties""" start="00:05:27.820" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""You can also have custom properties""" start="00:05:27.820" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that you name and then use yourself.""" start="00:05:29.761" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""For example, you can use it to mark regions in the buffer.""" start="00:05:31.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""You can also use it to add information""" start="00:05:35.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to regions in the buffer for your own tracking""" start="00:05:38.009" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""in a minor mode or something like that, which we will use.""" start="00:05:41.180" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Notes on properties""" start="00:05:45.380" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Finally, two notes on properties.""" start="00:05:45.380" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We've been talking about overlay properties,""" start="00:05:49.620" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but there's also something called text properties.""" start="00:05:51.951" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Text properties are attached to text in a buffer.""" start="00:05:54.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""When you copy that text, the properties come along with it.""" start="00:05:57.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""If you modify the properties,""" start="00:06:00.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the buffer is considered modified.""" start="00:06:03.057" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Org Mode makes heavy use of text properties,""" start="00:06:05.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""as we can see by running this little code snippet here,""" start="00:06:08.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which is going to tell us the properties""" start="00:06:11.678" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and the string attached""" start="00:06:14.060" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to the &quot;Some poetry&quot; headline on the right.""" start="00:06:16.566" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There's also some controversy regarding performance.""" start="00:06:20.740" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It may be that text properties""" start="00:06:23.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""perform better than overlay properties,""" start="00:06:25.521" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""so do some research""" start="00:06:27.860" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""if you're going to make heavy use of them.""" start="00:06:28.893" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I prefer overlays because they're just easier to use.""" start="00:06:31.060" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Improving C++ compiler output""" start="00:06:36.100" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""C++ compiler output.""" start="00:06:36.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So my day job is C++ programmer,""" start="00:06:37.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and although I've been an Emacser for many years,""" start="00:06:41.171" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it can be a little bit of a chore dealing with errors.""" start="00:06:46.561" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The error messages that come out of the compiler""" start="00:06:52.860" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""can be pretty hard to understand.""" start="00:06:55.681" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""This has often been a barrier,""" start="00:06:57.580" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""particularly for people who are new to C++.""" start="00:07:00.538" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So let's see what that's like.""" start="00:07:04.640" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I have an example""" start="00:07:09.040" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which is generously supplied by Ben Deane of Intel.""" start="00:07:10.560" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So let's see what it looks like""" start="00:07:14.780" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""when you compile a C++ program""" start="00:07:17.083" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that has a difficult error in it.""" start="00:07:19.314" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Okay.""" start="00:07:24.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Okay.""" start="00:07:28.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So you see we have a lot of fairly verbose messages.""" start="00:07:31.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The most verbose one I think is probably here.""" start="00:07:35.680" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""This one here.""" start="00:07:39.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""These are pretty bad.""" start="00:07:41.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I think there might be bigger ones.""" start="00:07:42.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Oh, yeah. Here we go.""" start="00:07:43.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Here's my favorite one.""" start="00:07:43.721" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""You can see... Let's look for specialization... Basically,""" start="00:07:44.961" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""this whole section of the buffer here,""" start="00:07:51.064" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that is specifying the specific types""" start="00:07:55.179" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that a function template was instantiated with.""" start="00:07:58.229" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And it's a lot there.""" start="00:08:02.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So if you're trying to figure out""" start="00:08:04.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""what's wrong with your program""" start="00:08:05.474" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and you're looking at something like this,""" start="00:08:06.818" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it can be really, really hard to understand.""" start="00:08:08.885" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Okay.""" start="00:08:11.000" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Back to our presentation.""" start="00:08:12.000" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""The problem with C++ error messages""" start="00:08:17.680" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""So it's often this way in C++""" start="00:08:17.680" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""because we compose types from other types.""" start="00:08:20.064" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""They can be long to begin with,""" start="00:08:23.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but then a couple of other factors come into play.""" start="00:08:26.217" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Many standard class templates have defalut arguments""" start="00:08:30.240" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""First of all, we can have default template arguments.""" start="00:08:30.240" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""These are arguments you didn't write,""" start="00:08:33.280" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but that are implicitly there""" start="00:08:35.364" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and can sometimes refer""" start="00:08:37.009" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to the arguments that you did write,""" start="00:08:38.326" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which causes them to get a bit bigger,""" start="00:08:40.301" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""such as these allocator arguments here and here.""" start="00:08:42.441" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Some types are aliases for longer things, too""" start="00:08:47.520" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Then there are type aliases.""" start="00:08:47.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""For example, `std::string` here expands to""" start="00:08:49.360" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""a type with three template arguments.""" start="00:08:54.015" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So you can imagine, when we combine""" start="00:08:58.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""those two things together,""" start="00:09:01.941" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""our simple vector of maps from strings to ints""" start="00:09:04.734" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""becomes this humongous thing here, which...""" start="00:09:09.764" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's run the comparison.""" start="00:09:14.258" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Yeah.""" start="00:09:18.360" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Reporting type information accurately means long lines""" start="00:09:20.960" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""So in summary, to properly understand an error""" start="00:09:20.960" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""when you're a C++ programmer""" start="00:09:24.925" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""requires knowing the exact types""" start="00:09:27.371" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that were supplied to your function.""" start="00:09:29.719" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And types are built recursively,""" start="00:09:32.280" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and therefore the types can--""" start="00:09:34.431" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the correct exact name for the type""" start="00:09:36.647" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""can just be really huge""" start="00:09:40.514" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and have many levels and layers to it.""" start="00:09:42.777" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So when I was trying to understand""" start="00:09:46.360" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the things I'd done wrong,""" start="00:09:48.114" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""especially when I was a newer C++ programmer,""" start="00:09:49.467" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but honestly still even recently,""" start="00:09:52.402" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""if I was having a really intractable problem,""" start="00:09:54.571" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I would just copy the entire error message out,""" start="00:09:57.440" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""stick it in the scratch buffer,""" start="00:10:00.124" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and then manually reformat it""" start="00:10:01.736" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""so I could see what it was telling me""" start="00:10:03.650" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I'd actually called the function""" start="00:10:05.564" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or whatever it was with, the exact type.""" start="00:10:07.262" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I had to sit there""" start="00:10:09.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and go through the whole thing.""" start="00:10:11.312" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""But there's a better way.""" start="00:10:13.240" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now, anyway.""" start="00:10:15.240" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Emacs can help - Treat C++ type names as just another kind of balanced expression""" start="00:10:18.240" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""So what can Emacs do to help us with this problem?""" start="00:10:18.240" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""First of all, if you think about a type name,""" start="00:10:23.960" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it's a lot like what we call S-expressions""" start="00:10:28.871" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or balanced expressions.""" start="00:10:33.080" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Lisp code itself is an S-expression.""" start="00:10:35.480" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It's basically things with parentheses""" start="00:10:38.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and little atoms or symbols in it,""" start="00:10:41.465" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or strings or numbers.""" start="00:10:44.215" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""But parenthesized balanced expressions""" start="00:10:46.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""are things that Emacs was actually built to deal with.""" start="00:10:50.232" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""They were... I found an old manual from 1981,""" start="00:10:55.800" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and the two major modes that they recommended""" start="00:10:58.945" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or that they actually documented in the manual were""" start="00:11:02.160" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""one, assembly language, and two, Lisp.""" start="00:11:05.766" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""They mentioned that there were other modes,""" start="00:11:08.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""but they didn't say anything about them.""" start="00:11:10.653" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So Lisp is something""" start="00:11:12.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with a really long history with Emacs.""" start="00:11:14.626" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Balanced expressions and manipulating them""" start="00:11:17.440" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and doing them efficiently""" start="00:11:19.977" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""is just a thing that Emacs knows how to do,""" start="00:11:21.435" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and Emacs is good at it.""" start="00:11:24.156" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There's just a legacy""" start="00:11:25.640" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""of algorithms and functions for doing it.""" start="00:11:27.706" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So we take types,""" start="00:11:31.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and we take the angle brackets in the types,""" start="00:11:33.183" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and we get the symbols right.""" start="00:11:37.840" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Then we can treat them""" start="00:11:40.840" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""as though they were balanced expressions or S-expressions,""" start="00:11:41.815" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the same kind that Emacs is really good at handling.""" start="00:11:44.313" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Add overlays to improve readability""" start="00:11:49.320" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Secondly, we can use overlays""" start="00:11:49.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to improve the readability of errors.""" start="00:11:51.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We can take long lines and break and indent them""" start="00:11:55.260" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""using `before-string`s, so the same thing""" start="00:11:58.013" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I used to add &quot;cherries&quot; into the poem.""" start="00:12:00.200" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We can use that to insert new lines""" start="00:12:03.440" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""followed by indentation""" start="00:12:06.612" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and produce a much nicer-looking listing of a type.""" start="00:12:08.726" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We can also use the `invisible` property""" start="00:12:15.160" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to hide unwanted detail.""" start="00:12:19.642" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Create a minor mode that runs during compilation""" start="00:12:22.400" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Last of all, we can create a minor mode.""" start="00:12:22.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""When we're compiling things in Emacs,""" start="00:12:24.960" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""we often use `compilation-mode`.""" start="00:12:27.855" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""`compilation-mode` allows you to install""" start="00:12:30.140" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""compilation filters that run""" start="00:12:32.098" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""when the compiler is producing output,""" start="00:12:33.554" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and at that time, then, we can add our overlays.""" start="00:12:36.435" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We can also add in minor-mode commands""" start="00:12:39.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that do whatever we want to the keymap.""" start="00:12:42.869" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""In this case, we're going to show and hide""" start="00:12:45.758" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""lower-level details interactively""" start="00:12:48.322" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""so that we can see a simplified version""" start="00:12:50.177" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or a more detailed version of a type, depending on our needs.""" start="00:12:53.907" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Parsing types as balanced expressions""" start="00:12:59.500" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""First of all, parsing types as balanced expressions.""" start="00:12:59.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We need to be able to quickly locate""" start="00:13:03.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the boundaries and the contents""" start="00:13:05.687" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""of parenthesized expressions,""" start="00:13:07.163" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""or in this case, expressions in angle brackets.""" start="00:13:08.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We use a syntax table inside Emacs""" start="00:13:12.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to allow movement functions like `forward-list`""" start="00:13:14.996" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to jump between matching angle brackets.""" start="00:13:18.801" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""By default, they're just parentheses.""" start="00:13:21.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""First of all, let's look at our syntax table.""" start="00:13:23.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We're going to add here syntax entries""" start="00:13:25.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to handle angle brackets as though they were parentheses.""" start="00:13:29.190" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Then we have a lot of types""" start="00:13:33.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that have colons in them, and those are namespaces in C++.""" start="00:13:37.248" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""By default, Emacs does not recognize them""" start="00:13:42.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""as parts of symbols, so we're going to tell Emacs""" start="00:13:45.767" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that a colon is something called a symbol constituent,""" start="00:13:49.135" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that it can be part of a name.""" start="00:13:52.840" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Once we do that, then we can use our functions""" start="00:13:54.860" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""like `forward-list`, `backward-word`,""" start="00:13:57.614" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""all of the navigation and movement functions that we have""" start="00:13:59.443" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that do things, that do more complicated things""" start="00:14:03.289" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""like S-expressions and so on,""" start="00:14:06.624" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""can be used now with our angle brackets""" start="00:14:08.708" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and inside of our types.""" start="00:14:11.486" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Indent and fill with overlays - Use ancient "pretty printing" algorithms"""" start="00:14:16.100" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""The next thing we can do is""" start="00:14:16.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""perform indent and fill with overlays.""" start="00:14:18.463" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We're going to use `before-string` properties""" start="00:14:21.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to break lines and create indentation""" start="00:14:23.736" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to make the output look a little better.""" start="00:14:25.631" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Today, we fill mostly text and we indent mostly code.""" start="00:14:28.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We fill text in order to prevent it""" start="00:14:35.320" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""from running off the side of the right margin,""" start="00:14:37.308" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and we indent code to line up syntactic elements.""" start="00:14:39.903" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Back in the day, they had algorithms that could do both.""" start="00:14:43.940" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Those are what we're going to leverage.""" start="00:14:47.080" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Overlays can mimic line breaks and indentation""" start="00:14:52.260" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""We can use the `before-string` property""" start="00:14:52.260" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to insert a new line in the correct number of spaces""" start="00:14:54.583" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to emulate indentation.""" start="00:14:57.760" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""As a simplified example, here's some code""" start="00:15:00.240" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that will indent 4 upon each open angle bracket.""" start="00:15:03.526" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's give it a try.""" start="00:15:07.280" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Hiding details - Marking depths with overlays""" start="00:15:14.520" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""The next thing we're going to need to do is hide details.""" start="00:15:14.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So we have nested types, and the user is going to want to""" start="00:15:18.280" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""be able to reveal lower-level or hide lower-level parts""" start="00:15:22.689" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""of the nested type interactively""" start="00:15:27.372" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""once we've already reformatted the error messages.""" start="00:15:30.132" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's see how we can do that using invisible properties.""" start="00:15:35.480" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""The first thing we're going to do is""" start="00:15:40.440" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""mark depths within the type.""" start="00:15:43.993" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""When we're originally analyzing and formatting""" start="00:15:46.680" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and doing the indentation and the line breaks,""" start="00:15:49.329" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""at the same time, we're going to go through""" start="00:15:51.920" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and mark the nested levels inside the type names,""" start="00:15:55.072" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""just as this diagram shows.""" start="00:15:58.818" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So depth 1, for example, will be everything""" start="00:16:00.840" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""inside the first level of angle brackets.""" start="00:16:03.574" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Depth 2 will be everything inside the second level,""" start="00:16:06.120" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and so on.""" start="00:16:09.039" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And then later on, when the users request it,""" start="00:16:09.760" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""we can go and look at the depth that they've selected""" start="00:16:12.071" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and then mark those sections invisible.""" start="00:16:16.304" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's see how that might work.""" start="00:16:19.360" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""First of all, let's delete the overlays""" start="00:16:20.520" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that we already have that created the indentation.""" start="00:16:24.023" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now we're going to go and do that marking""" start="00:16:28.400" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with the custom depth properties here.""" start="00:16:32.420" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""To prove that I didn't pull a fast one,""" start="00:16:35.740" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""let's go and see what `describe-char` tells us""" start="00:16:38.761" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""about the depths inside here.""" start="00:16:42.083" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's start here.""" start="00:16:44.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Okay, so inside this part here, `std::string`,""" start="00:16:46.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""There are two overlays.""" start="00:16:52.820" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""One of them is of depth 1, and the other is of depth 2,""" start="00:16:54.980" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which makes sense, because depth 1 is going to be""" start="00:16:57.781" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""from about here to here,""" start="00:17:00.602" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and depth 2 is going to be from about here to this area.""" start="00:17:02.012" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So it's reasonable that there should be two,""" start="00:17:07.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and that's what we expect.""" start="00:17:10.830" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Hiding to a target depth""" start="00:17:12.660" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Now that we've marked the nested types with their depths,""" start="00:17:12.660" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""let's experiment with hiding details.""" start="00:17:17.354" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""This fragment of code takes a user-supplied depth,""" start="00:17:21.380" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""in this case 2, and will hide,""" start="00:17:26.774" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""based on those markings""" start="00:17:29.086" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that we've already made on the overlays,""" start="00:17:30.876" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""the custom depth properties.""" start="00:17:33.933" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We'll take those and apply your requested level of detail.""" start="00:17:36.020" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So let's try it out.""" start="00:17:40.020" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Depth 2.""" start="00:17:42.020" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""All right, that hid everything under the `std::map`,""" start="00:17:43.020" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""so the deepest level.""" start="00:17:46.006" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""If we make it 1, we should get a level higher than that.""" start="00:17:47.260" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So now level 1 and below are hidden.""" start="00:17:52.140" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now if we put it back to 3, it should reveal everything.""" start="00:17:54.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""So that's what we're going to use in our minor mode.""" start="00:17:59.660" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Demo""" start="00:18:04.900" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""Let's have a demo.""" start="00:18:04.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We're going to revisit the initial example""" start="00:18:05.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with the minor mode installed.""" start="00:18:08.539" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now we're going to have a compilation filter""" start="00:18:10.380" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that will run on every chunk of output""" start="00:18:12.102" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""produced by the compiler.""" start="00:18:13.594" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It's going to add those overlays""" start="00:18:15.780" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with the line breaks and the indentation.""" start="00:18:17.850" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""It's also going to add overlays""" start="00:18:20.420" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that mark up the nested types""" start="00:18:22.207" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with the depths for each region.""" start="00:18:23.881" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's add the hook for `tspew-mode`.""" start="00:18:26.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And now we can compile again.""" start="00:18:31.580" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""All right, we can already see""" start="00:18:38.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that these things are formatted a little bit better""" start="00:18:41.504" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""than they were before.""" start="00:18:47.196" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""They're not all on one line.""" start="00:18:49.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Things are getting kind of lined up here.""" start="00:18:50.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Here's a good example.""" start="00:18:53.580" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And here's our big ugly one from before""" start="00:19:05.620" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""with all the characters in it.""" start="00:19:08.638" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's try hiding some of this information.""" start="00:19:10.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""We'll just slowly decrease the level of detail""" start="00:19:14.500" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and you can see how it works.""" start="00:19:17.432" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Over here, where there's these ellipses""" start="00:19:19.740" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""next to string constant, the &quot;...&quot; there,""" start="00:19:22.334" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""that's where we are starting to hide information""" start="00:19:25.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and go to the next level.""" start="00:19:30.387" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Hiding more, hiding more, hiding more.""" start="00:19:32.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Now we can go back and start adding it back.""" start="00:19:36.460" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""You can see here now we just have about four layers,""" start="00:19:38.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""which is a lot easier to understand.""" start="00:19:42.737" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And if we start understanding what it is""" start="00:19:45.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and we need more detail, we can just increase detail again.""" start="00:19:47.734" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""And every time we increase or decrease detail,""" start="00:19:52.180" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""it reformats so it still stays kind of consolidated""" start="00:19:55.403" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and nice looking.""" start="00:19:58.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's increase it a little bit more.""" start="00:19:59.900" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Okay, so you can see how that worked.""" start="00:20:02.060" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Let's go back to our presentation.""" start="00:20:04.540" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""All right.""" start="00:20:08.340" video="mainVideo-overlay" id="subtitle"]]

[[!template new="1" text="""Conclusion""" start="00:20:10.220" video="mainVideo-overlay" id="subtitle"]]

[[!template text="""In conclusion, we saw how we could solve""" start="00:20:10.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""a real problem for C++ programmers""" start="00:20:12.997" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""by combining several Emacs features: overlays,""" start="00:20:15.368" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""compilation mode extensions,""" start="00:20:18.535" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""and balanced expression navigation using syntax tables.""" start="00:20:20.490" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Emacs is often compared unfavorably""" start="00:20:25.700" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""to newer IDEs and editors with slicker user interfaces.""" start="00:20:27.979" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""What Emacs has that they don't is powerful abstractions,""" start="00:20:32.220" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""tons of libraries, and decades of work""" start="00:20:36.387" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""by some of the luminaries in the field of software.""" start="00:20:38.863" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""I think that this project would have been much harder to do""" start="00:20:42.100" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""in a prettier but less powerful environment.""" start="00:20:45.344" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""In short, there's plenty of hope for Emacs.""" start="00:20:48.020" video="mainVideo-overlay" id="subtitle"]]
[[!template text="""Thank you.""" start="00:20:50.860" video="mainVideo-overlay" id="subtitle"]]



Captioner: sachac

Questions or comments? Please e-mail [emacsconf-org-private@gnu.org](mailto:emacsconf-org-private@gnu.org?subject=Comment%20for%20EmacsConf%202023%20overlay%3A%20Improving%20compiler%20diagnostics%20with%20overlays)


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