[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.62,0:00:05.04,Default,,0000,0000,0000,,all right everyone let's get started
Dialogue: 0,0:00:03.12,0:00:07.65,Default,,0000,0000,0000,,with the next lecture so today we're
Dialogue: 0,0:00:05.04,0:00:09.75,Default,,0000,0000,0000,,gonna that tackle the topic of meta
Dialogue: 0,0:00:07.65,0:00:11.70,Default,,0000,0000,0000,,programming and this title is a little
Dialogue: 0,0:00:09.75,0:00:13.59,Default,,0000,0000,0000,,weird it's not entirely clear what we
Dialogue: 0,0:00:11.70,0:00:14.97,Default,,0000,0000,0000,,mean by meta programming we couldn't
Dialogue: 0,0:00:13.59,0:00:17.13,Default,,0000,0000,0000,,really come up with a better name for
Dialogue: 0,0:00:14.97,0:00:20.76,Default,,0000,0000,0000,,this lecture because this lecture is
Dialogue: 0,0:00:17.13,0:00:22.26,Default,,0000,0000,0000,,about the processes that surround the
Dialogue: 0,0:00:20.76,0:00:24.69,Default,,0000,0000,0000,,work that you do when working with
Dialogue: 0,0:00:22.26,0:00:27.51,Default,,0000,0000,0000,,software it is not about programming
Dialogue: 0,0:00:24.69,0:00:30.54,Default,,0000,0000,0000,,itself necessarily but about the process
Dialogue: 0,0:00:27.51,0:00:33.84,Default,,0000,0000,0000,,this can be things like how your system
Dialogue: 0,0:00:30.54,0:00:35.94,Default,,0000,0000,0000,,is built how it's tested how you add
Dialogue: 0,0:00:33.84,0:00:37.41,Default,,0000,0000,0000,,dependencies to your software that sort
Dialogue: 0,0:00:35.94,0:00:39.72,Default,,0000,0000,0000,,of stuff that becomes really relevant
Dialogue: 0,0:00:37.41,0:00:42.42,Default,,0000,0000,0000,,when you build larger pieces of software
Dialogue: 0,0:00:39.72,0:00:44.12,Default,,0000,0000,0000,,but they're not really programming in
Dialogue: 0,0:00:42.42,0:00:46.47,Default,,0000,0000,0000,,and of themselves
Dialogue: 0,0:00:44.12,0:00:49.08,Default,,0000,0000,0000,,so the first thing we're going to talk
Dialogue: 0,0:00:46.47,0:00:51.72,Default,,0000,0000,0000,,about in this lecture is the notion of
Dialogue: 0,0:00:49.08,0:00:53.79,Default,,0000,0000,0000,,build systems so how many of you have
Dialogue: 0,0:00:51.72,0:00:59.40,Default,,0000,0000,0000,,used a build system before or know what
Dialogue: 0,0:00:53.79,0:01:01.80,Default,,0000,0000,0000,,it is okay so about 1/2 of you so for
Dialogue: 0,0:00:59.40,0:01:04.95,Default,,0000,0000,0000,,the rest of you the the central idea
Dialogue: 0,0:01:01.80,0:01:07.32,Default,,0000,0000,0000,,behind a build system is that you're
Dialogue: 0,0:01:04.95,0:01:09.51,Default,,0000,0000,0000,,writing a paper you're writing software
Dialogue: 0,0:01:07.32,0:01:12.09,Default,,0000,0000,0000,,you're like working on a class whatever
Dialogue: 0,0:01:09.51,0:01:14.01,Default,,0000,0000,0000,,it might be and you have a bunch of
Dialogue: 0,0:01:12.09,0:01:15.81,Default,,0000,0000,0000,,commands that you like either written
Dialogue: 0,0:01:14.01,0:01:17.52,Default,,0000,0000,0000,,down in your shell history or you wrote
Dialogue: 0,0:01:15.81,0:01:19.05,Default,,0000,0000,0000,,them down in a document somewhere that
Dialogue: 0,0:01:17.52,0:01:20.76,Default,,0000,0000,0000,,you know you have to run if you want to
Dialogue: 0,0:01:19.05,0:01:22.59,Default,,0000,0000,0000,,do a particular thing so for example
Dialogue: 0,0:01:20.76,0:01:23.82,Default,,0000,0000,0000,,like there are a sequence of commands so
Dialogue: 0,0:01:22.59,0:01:27.48,Default,,0000,0000,0000,,you need to run in order to build your
Dialogue: 0,0:01:23.82,0:01:29.34,Default,,0000,0000,0000,,paper or build your thesis or just to
Dialogue: 0,0:01:27.48,0:01:32.94,Default,,0000,0000,0000,,run the tests for whatever class you're
Dialogue: 0,0:01:29.34,0:01:35.07,Default,,0000,0000,0000,,currently in and a build system sort of
Dialogue: 0,0:01:32.94,0:01:37.65,Default,,0000,0000,0000,,idea is that you want to encode these
Dialogue: 0,0:01:35.07,0:01:40.38,Default,,0000,0000,0000,,rules for what commands to run in order
Dialogue: 0,0:01:37.65,0:01:43.56,Default,,0000,0000,0000,,to build particular targets into a tool
Dialogue: 0,0:01:40.38,0:01:45.21,Default,,0000,0000,0000,,that can do it for you and in particular
Dialogue: 0,0:01:43.56,0:01:47.25,Default,,0000,0000,0000,,you're going to teach this tool about
Dialogue: 0,0:01:45.21,0:01:51.09,Default,,0000,0000,0000,,the dependencies between those different
Dialogue: 0,0:01:47.25,0:01:54.30,Default,,0000,0000,0000,,artifacts that you might build there are
Dialogue: 0,0:01:51.09,0:01:56.58,Default,,0000,0000,0000,,a lot of different types of tools of
Dialogue: 0,0:01:54.30,0:01:57.84,Default,,0000,0000,0000,,this kind and many of them are built for
Dialogue: 0,0:01:56.58,0:02:00.29,Default,,0000,0000,0000,,particular purposes particularly
Dialogue: 0,0:01:57.84,0:02:02.40,Default,,0000,0000,0000,,languages some of them are built for
Dialogue: 0,0:02:00.29,0:02:04.35,Default,,0000,0000,0000,,building like papers some of them are
Dialogue: 0,0:02:02.40,0:02:06.12,Default,,0000,0000,0000,,built for building software some of them
Dialogue: 0,0:02:04.35,0:02:09.99,Default,,0000,0000,0000,,are built for particularly programming
Dialogue: 0,0:02:06.12,0:02:13.14,Default,,0000,0000,0000,,languages like Java or some some tools
Dialogue: 0,0:02:09.99,0:02:15.63,Default,,0000,0000,0000,,even have built in tools for for builds
Dialogue: 0,0:02:13.14,0:02:17.34,Default,,0000,0000,0000,,so NPM for example you might be aware if
Dialogue: 0,0:02:15.63,0:02:19.25,Default,,0000,0000,0000,,you've done Nodejs development has a
Dialogue: 0,0:02:17.34,0:02:21.42,Default,,0000,0000,0000,,bunch of built-in tools for doing
Dialogue: 0,0:02:19.25,0:02:23.28,Default,,0000,0000,0000,,tracking of dependencies and building
Dialogue: 0,0:02:21.42,0:02:25.23,Default,,0000,0000,0000,,them and building all of the dependent
Dialogue: 0,0:02:23.28,0:02:27.24,Default,,0000,0000,0000,,stuff of your software but more
Dialogue: 0,0:02:25.23,0:02:29.55,Default,,0000,0000,0000,,generally these are known as build
Dialogue: 0,0:02:27.24,0:02:32.76,Default,,0000,0000,0000,,systems and at their core they all
Dialogue: 0,0:02:29.55,0:02:35.70,Default,,0000,0000,0000,,function in a very similar way and that
Dialogue: 0,0:02:32.76,0:02:37.47,Default,,0000,0000,0000,,is you have a number of targets these
Dialogue: 0,0:02:35.70,0:02:41.13,Default,,0000,0000,0000,,are the things that you want to build
Dialogue: 0,0:02:37.47,0:02:42.45,Default,,0000,0000,0000,,these are things like paper dot PDF but
Dialogue: 0,0:02:41.13,0:02:45.18,Default,,0000,0000,0000,,they can also be more abstract things
Dialogue: 0,0:02:42.45,0:02:47.25,Default,,0000,0000,0000,,like run the test suite or build the
Dialogue: 0,0:02:45.18,0:02:49.23,Default,,0000,0000,0000,,binary for this program then you have a
Dialogue: 0,0:02:47.25,0:02:51.12,Default,,0000,0000,0000,,bunch of dependencies and dependencies
Dialogue: 0,0:02:49.23,0:02:53.04,Default,,0000,0000,0000,,are things that need to be built in
Dialogue: 0,0:02:51.12,0:02:55.71,Default,,0000,0000,0000,,order for this thing to be built and
Dialogue: 0,0:02:53.04,0:02:57.63,Default,,0000,0000,0000,,then you have rules that define how do
Dialogue: 0,0:02:55.71,0:03:00.84,Default,,0000,0000,0000,,you go from a complete list of
Dialogue: 0,0:02:57.63,0:03:02.82,Default,,0000,0000,0000,,dependencies to the given target so an
Dialogue: 0,0:03:00.84,0:03:05.37,Default,,0000,0000,0000,,example of this might be in order to
Dialogue: 0,0:03:02.82,0:03:08.91,Default,,0000,0000,0000,,build my paper dot PDF I need a bunch of
Dialogue: 0,0:03:05.37,0:03:10.74,Default,,0000,0000,0000,,like plot images they're gonna go into
Dialogue: 0,0:03:08.91,0:03:12.75,Default,,0000,0000,0000,,the paper so they need to be built but
Dialogue: 0,0:03:10.74,0:03:15.21,Default,,0000,0000,0000,,then once they have been built how do i
Dialogue: 0,0:03:12.75,0:03:16.86,Default,,0000,0000,0000,,construct the paper given those files so
Dialogue: 0,0:03:15.21,0:03:18.33,Default,,0000,0000,0000,,that is what a rule is it's a sequence
Dialogue: 0,0:03:16.86,0:03:21.45,Default,,0000,0000,0000,,of command so you run to get from one to
Dialogue: 0,0:03:18.33,0:03:24.21,Default,,0000,0000,0000,,the other how you encode these rules
Dialogue: 0,0:03:21.45,0:03:25.65,Default,,0000,0000,0000,,differs between different tools in this
Dialogue: 0,0:03:24.21,0:03:28.80,Default,,0000,0000,0000,,particular class we're gonna focus on a
Dialogue: 0,0:03:25.65,0:03:31.20,Default,,0000,0000,0000,,tool called make make is a tool that you
Dialogue: 0,0:03:28.80,0:03:33.42,Default,,0000,0000,0000,,will find on almost any system that you
Dialogue: 0,0:03:31.20,0:03:35.70,Default,,0000,0000,0000,,log in today like it'll be on Mac OS
Dialogue: 0,0:03:33.42,0:03:38.31,Default,,0000,0000,0000,,it'll be on basically every Linux and
Dialogue: 0,0:03:35.70,0:03:41.01,Default,,0000,0000,0000,,BSD system and you can pretty easily get
Dialogue: 0,0:03:38.31,0:03:43.05,Default,,0000,0000,0000,,it on Windows um it's not great for very
Dialogue: 0,0:03:41.01,0:03:45.03,Default,,0000,0000,0000,,complex software but it works really
Dialogue: 0,0:03:43.05,0:03:49.50,Default,,0000,0000,0000,,well for anything that's sort of simple
Dialogue: 0,0:03:45.03,0:03:51.54,Default,,0000,0000,0000,,to medium complexity now when you run
Dialogue: 0,0:03:49.50,0:03:53.40,Default,,0000,0000,0000,,make to make user command you can run on
Dialogue: 0,0:03:51.54,0:03:56.31,Default,,0000,0000,0000,,the command line and when you type make
Dialogue: 0,0:03:53.40,0:03:58.71,Default,,0000,0000,0000,,and this is an empty directory if I type
Dialogue: 0,0:03:56.31,0:04:02.40,Default,,0000,0000,0000,,make it just has no target specified and
Dialogue: 0,0:03:58.71,0:04:03.57,Default,,0000,0000,0000,,no make file found stop and so it
Dialogue: 0,0:04:02.40,0:04:06.42,Default,,0000,0000,0000,,helpfully tells you that it stopped
Dialogue: 0,0:04:03.57,0:04:09.36,Default,,0000,0000,0000,,running but also tells you that no make
Dialogue: 0,0:04:06.42,0:04:11.34,Default,,0000,0000,0000,,file was found make will look for a file
Dialogue: 0,0:04:09.36,0:04:13.05,Default,,0000,0000,0000,,literally called make file in the
Dialogue: 0,0:04:11.34,0:04:14.94,Default,,0000,0000,0000,,current directory and that is where you
Dialogue: 0,0:04:13.05,0:04:18.45,Default,,0000,0000,0000,,encode these targets dependencies and
Dialogue: 0,0:04:14.94,0:04:19.50,Default,,0000,0000,0000,,rules so let's try to write one let's
Dialogue: 0,0:04:18.45,0:04:22.05,Default,,0000,0000,0000,,imagine that I'm writing this
Dialogue: 0,0:04:19.50,0:04:23.94,Default,,0000,0000,0000,,hypothetical paper and so I'm gonna make
Dialogue: 0,0:04:22.05,0:04:26.49,Default,,0000,0000,0000,,a make file and then this make file I'm
Dialogue: 0,0:04:23.94,0:04:27.96,Default,,0000,0000,0000,,going to say that my paper dog PDF the
Dialogue: 0,0:04:26.49,0:04:30.87,Default,,0000,0000,0000,,hands-on that's what the : here
Dialogue: 0,0:04:27.96,0:04:35.82,Default,,0000,0000,0000,,indicates paper dot text was going to be
Dialogue: 0,0:04:30.87,0:04:40.08,Default,,0000,0000,0000,,a little attack file and plot data dot
Dialogue: 0,0:04:35.82,0:04:42.90,Default,,0000,0000,0000,,PNG and the command in order to build
Dialogue: 0,0:04:40.08,0:04:46.26,Default,,0000,0000,0000,,this is going to be PDF latex of paper
Dialogue: 0,0:04:42.90,0:04:47.55,Default,,0000,0000,0000,,dot Tex so for those of you who are not
Dialogue: 0,0:04:46.26,0:04:50.07,Default,,0000,0000,0000,,familiar with this particular way of
Dialogue: 0,0:04:47.55,0:04:53.10,Default,,0000,0000,0000,,building documents the tech is a really
Dialogue: 0,0:04:50.07,0:04:56.43,Default,,0000,0000,0000,,handy programming language for documents
Dialogue: 0,0:04:53.10,0:04:57.96,Default,,0000,0000,0000,,it's a really ugly language and it's a
Dialogue: 0,0:04:56.43,0:05:01.23,Default,,0000,0000,0000,,pain to work with but it produces pretty
Dialogue: 0,0:04:57.96,0:05:05.12,Default,,0000,0000,0000,,nice documents and the tool you use to
Dialogue: 0,0:05:01.23,0:05:08.52,Default,,0000,0000,0000,,go from a tech file to PDF is PDF latex
Dialogue: 0,0:05:05.12,0:05:12.30,Default,,0000,0000,0000,,and here I'm saying that I also depend
Dialogue: 0,0:05:08.52,0:05:14.46,Default,,0000,0000,0000,,on this plot plot data PNG that's gonna
Dialogue: 0,0:05:12.30,0:05:16.71,Default,,0000,0000,0000,,be included in my document and what I'm
Dialogue: 0,0:05:14.46,0:05:19.35,Default,,0000,0000,0000,,really saying here is if either of those
Dialogue: 0,0:05:16.71,0:05:22.02,Default,,0000,0000,0000,,two dependencies change I want you to
Dialogue: 0,0:05:19.35,0:05:23.85,Default,,0000,0000,0000,,build paper PDF they both need to be
Dialogue: 0,0:05:22.02,0:05:26.43,Default,,0000,0000,0000,,present and should they ever change I
Dialogue: 0,0:05:23.85,0:05:28.23,Default,,0000,0000,0000,,wanted to rebuild it but I haven't
Dialogue: 0,0:05:26.43,0:05:30.60,Default,,0000,0000,0000,,really told it how to generate this plot
Dialogue: 0,0:05:28.23,0:05:31.86,Default,,0000,0000,0000,,data PNG so I might want to rule for
Dialogue: 0,0:05:30.60,0:05:34.02,Default,,0000,0000,0000,,that as well
Dialogue: 0,0:05:31.86,0:05:35.82,Default,,0000,0000,0000,,so I'm gonna define another target here
Dialogue: 0,0:05:34.02,0:05:41.67,Default,,0000,0000,0000,,and it's gonna be it's gonna look like
Dialogue: 0,0:05:35.82,0:05:45.36,Default,,0000,0000,0000,,this plot - % & % means and make is any
Dialogue: 0,0:05:41.67,0:05:46.89,Default,,0000,0000,0000,,string sort of a wildcard pattern but
Dialogue: 0,0:05:45.36,0:05:49.74,Default,,0000,0000,0000,,the cool thing is a you go and repeat
Dialogue: 0,0:05:46.89,0:05:53.01,Default,,0000,0000,0000,,this pattern in the dependencies so I
Dialogue: 0,0:05:49.74,0:05:59.10,Default,,0000,0000,0000,,can say that plot - % dot PNG is going
Dialogue: 0,0:05:53.01,0:06:02.09,Default,,0000,0000,0000,,to depend on % dott data or debt that is
Dialogue: 0,0:05:59.10,0:06:05.13,Default,,0000,0000,0000,,a common sort of suffix for data files
Dialogue: 0,0:06:02.09,0:06:07.02,Default,,0000,0000,0000,,and it's also going to depend on some
Dialogue: 0,0:06:05.13,0:06:09.06,Default,,0000,0000,0000,,script that's gonna actually plot this
Dialogue: 0,0:06:07.02,0:06:09.54,Default,,0000,0000,0000,,for me and the rules for to go from one
Dialogue: 0,0:06:09.06,0:06:11.37,Default,,0000,0000,0000,,to the other
Dialogue: 0,0:06:09.54,0:06:13.20,Default,,0000,0000,0000,,these can be multiple lines but in my
Dialogue: 0,0:06:11.37,0:06:15.54,Default,,0000,0000,0000,,particular case they're just one line
Dialogue: 0,0:06:13.20,0:06:21.42,Default,,0000,0000,0000,,I'm gonna explain what this is in a
Dialogue: 0,0:06:15.54,0:06:23.66,Default,,0000,0000,0000,,little second alright so here we're
Dialogue: 0,0:06:21.42,0:06:26.28,Default,,0000,0000,0000,,gonna say that in order to go from a
Dialogue: 0,0:06:23.66,0:06:29.13,Default,,0000,0000,0000,,wildcard dot dot file that matches the
Dialogue: 0,0:06:26.28,0:06:32.94,Default,,0000,0000,0000,,wildcard in the target and a plot dot
Dialogue: 0,0:06:29.13,0:06:34.44,Default,,0000,0000,0000,,python file run the python file with - i
Dialogue: 0,0:06:32.94,0:06:36.33,Default,,0000,0000,0000,,which is going to be like the way we
Dialogue: 0,0:06:34.44,0:06:37.98,Default,,0000,0000,0000,,take the mark what the input is in our
Dialogue: 0,0:06:36.33,0:06:40.01,Default,,0000,0000,0000,,python file I'll show it to you later
Dialogue: 0,0:06:37.98,0:06:42.17,Default,,0000,0000,0000,,dollarz star
Dialogue: 0,0:06:40.01,0:06:45.05,Default,,0000,0000,0000,,is a special variable that is defined
Dialogue: 0,0:06:42.17,0:06:47.81,Default,,0000,0000,0000,,for you and make file rules that matches
Dialogue: 0,0:06:45.05,0:06:50.69,Default,,0000,0000,0000,,whatever the percentile was so if I do
Dialogue: 0,0:06:47.81,0:06:53.24,Default,,0000,0000,0000,,plot to PNG then it's going to look for
Dialogue: 0,0:06:50.69,0:06:55.55,Default,,0000,0000,0000,,food dot that and it dollars stars can
Dialogue: 0,0:06:53.24,0:06:57.29,Default,,0000,0000,0000,,expand to foo so this will produce the
Dialogue: 0,0:06:55.55,0:06:59.78,Default,,0000,0000,0000,,same file name as the one we matched
Dialogue: 0,0:06:57.29,0:07:01.07,Default,,0000,0000,0000,,here and dollar act as a special
Dialogue: 0,0:06:59.78,0:07:04.96,Default,,0000,0000,0000,,variable that means the name of the
Dialogue: 0,0:07:01.07,0:07:07.37,Default,,0000,0000,0000,,target right so the output file and
Dialogue: 0,0:07:04.96,0:07:09.17,Default,,0000,0000,0000,,hopefully what plotter py will do is
Dialogue: 0,0:07:07.37,0:07:11.90,Default,,0000,0000,0000,,that it will take whatever the data is
Dialogue: 0,0:07:09.17,0:07:14.09,Default,,0000,0000,0000,,here it will produce a PNG somehow and
Dialogue: 0,0:07:11.90,0:07:18.11,Default,,0000,0000,0000,,it will write it into the file indicated
Dialogue: 0,0:07:14.09,0:07:19.70,Default,,0000,0000,0000,,by the dollar at all right so now we
Dialogue: 0,0:07:18.11,0:07:21.32,Default,,0000,0000,0000,,have a make file let's see what happens
Dialogue: 0,0:07:19.70,0:07:23.48,Default,,0000,0000,0000,,if the only file in this directory is
Dialogue: 0,0:07:21.32,0:07:25.70,Default,,0000,0000,0000,,the make file and we run make one says
Dialogue: 0,0:07:23.48,0:07:29.84,Default,,0000,0000,0000,,no rule to make target paper dot tex
Dialogue: 0,0:07:25.70,0:07:32.63,Default,,0000,0000,0000,,needed by paper dot PDF stop so what
Dialogue: 0,0:07:29.84,0:07:35.12,Default,,0000,0000,0000,,it's saying here is first of all it
Dialogue: 0,0:07:32.63,0:07:37.58,Default,,0000,0000,0000,,looked at the first rule of our file the
Dialogue: 0,0:07:35.12,0:07:39.26,Default,,0000,0000,0000,,first target and when you give make no
Dialogue: 0,0:07:37.58,0:07:41.06,Default,,0000,0000,0000,,arguments it tries to build whatever the
Dialogue: 0,0:07:39.26,0:07:43.31,Default,,0000,0000,0000,,first target is this is known as the
Dialogue: 0,0:07:41.06,0:07:45.68,Default,,0000,0000,0000,,default goal so in this case it tried to
Dialogue: 0,0:07:43.31,0:07:47.51,Default,,0000,0000,0000,,helpfully build paper dot PDF for us and
Dialogue: 0,0:07:45.68,0:07:49.88,Default,,0000,0000,0000,,then it looked up the dependencies and
Dialogue: 0,0:07:47.51,0:07:53.09,Default,,0000,0000,0000,,it said well in order to build paper dot
Dialogue: 0,0:07:49.88,0:07:56.09,Default,,0000,0000,0000,,PDF I need paper Tex and I need this PNG
Dialogue: 0,0:07:53.09,0:07:58.70,Default,,0000,0000,0000,,file and I can't find paper dot X and I
Dialogue: 0,0:07:56.09,0:08:00.95,Default,,0000,0000,0000,,don't have a rule for generating paper
Dialogue: 0,0:07:58.70,0:08:04.12,Default,,0000,0000,0000,,dot X and therefore I'm gonna exit this
Dialogue: 0,0:08:00.95,0:08:04.12,Default,,0000,0000,0000,,isn't nothing more I can do
Dialogue: 0,0:08:04.81,0:08:10.10,Default,,0000,0000,0000,,so let's try to make some files here
Dialogue: 0,0:08:07.43,0:08:13.94,Default,,0000,0000,0000,,let's just make like an empty paper dot
Dialogue: 0,0:08:10.10,0:08:15.95,Default,,0000,0000,0000,,X and then type make so now it says no
Dialogue: 0,0:08:13.94,0:08:18.20,Default,,0000,0000,0000,,rule to make target plot data dot PNG
Dialogue: 0,0:08:15.95,0:08:20.12,Default,,0000,0000,0000,,needed by paper to PDF right so now it's
Dialogue: 0,0:08:18.20,0:08:21.35,Default,,0000,0000,0000,,it knows that it has one dependency but
Dialogue: 0,0:08:20.12,0:08:24.32,Default,,0000,0000,0000,,it doesn't know how to get the other one
Dialogue: 0,0:08:21.35,0:08:26.21,Default,,0000,0000,0000,,it knows it as a target that matches but
Dialogue: 0,0:08:24.32,0:08:29.14,Default,,0000,0000,0000,,it can't actually find its dependencies
Dialogue: 0,0:08:26.21,0:08:31.91,Default,,0000,0000,0000,,and so it ends up doing nothing at all
Dialogue: 0,0:08:29.14,0:08:35.78,Default,,0000,0000,0000,,it still still needs us to generate this
Dialogue: 0,0:08:31.91,0:08:37.76,Default,,0000,0000,0000,,PNG for the input for the PNG so let's
Dialogue: 0,0:08:35.78,0:08:42.74,Default,,0000,0000,0000,,actually put some useful stuff into
Dialogue: 0,0:08:37.76,0:08:48.17,Default,,0000,0000,0000,,these files let's say that luckily I
Dialogue: 0,0:08:42.74,0:08:50.33,Default,,0000,0000,0000,,have one from earlier plot da py to here
Dialogue: 0,0:08:48.17,0:08:52.22,Default,,0000,0000,0000,,so let's so good well this text file is
Dialogue: 0,0:08:50.33,0:08:53.39,Default,,0000,0000,0000,,this is what text looks like it's not
Dialogue: 0,0:08:52.22,0:08:55.43,Default,,0000,0000,0000,,very pretty but
Dialogue: 0,0:08:53.39,0:08:57.20,Default,,0000,0000,0000,,see I'm defining an empty document I'm
Dialogue: 0,0:08:55.43,0:08:59.81,Default,,0000,0000,0000,,going to include graphics which is the
Dialogue: 0,0:08:57.20,0:09:01.85,Default,,0000,0000,0000,,way you include a an image file I'm
Dialogue: 0,0:08:59.81,0:09:04.07,Default,,0000,0000,0000,,going to include plot data dot PNG and
Dialogue: 0,0:09:01.85,0:09:06.11,Default,,0000,0000,0000,,this is of course why we want a
Dialogue: 0,0:09:04.07,0:09:10.13,Default,,0000,0000,0000,,dependency of peda paper dot PDF to be
Dialogue: 0,0:09:06.11,0:09:12.71,Default,,0000,0000,0000,,the PNG file plot the py is also not
Dialogue: 0,0:09:10.13,0:09:15.38,Default,,0000,0000,0000,,very interesting it just part imports a
Dialogue: 0,0:09:12.71,0:09:19.01,Default,,0000,0000,0000,,bunch libraries it parses the - ion - Oh
Dialogue: 0,0:09:15.38,0:09:22.88,Default,,0000,0000,0000,,arguments it loads data from the I
Dialogue: 0,0:09:19.01,0:09:24.71,Default,,0000,0000,0000,,argument it uses library called
Dialogue: 0,0:09:22.88,0:09:27.53,Default,,0000,0000,0000,,matplotlib which is very handy for just
Dialogue: 0,0:09:24.71,0:09:30.38,Default,,0000,0000,0000,,quickly plotting data and it's gonna
Dialogue: 0,0:09:27.53,0:09:32.99,Default,,0000,0000,0000,,plot the first column of the data as X's
Dialogue: 0,0:09:30.38,0:09:34.64,Default,,0000,0000,0000,,and the second column of the data as Y's
Dialogue: 0,0:09:32.99,0:09:37.10,Default,,0000,0000,0000,,so we're just going to have a data file
Dialogue: 0,0:09:34.64,0:09:39.83,Default,,0000,0000,0000,,that's two columns x and y on every line
Dialogue: 0,0:09:37.10,0:09:46.88,Default,,0000,0000,0000,,and then it saves that as a figure into
Dialogue: 0,0:09:39.83,0:09:49.52,Default,,0000,0000,0000,,whatever the given - oh value is okay so
Dialogue: 0,0:09:46.88,0:09:53.57,Default,,0000,0000,0000,,we need a data file that's going to be
Dialogue: 0,0:09:49.52,0:09:55.97,Default,,0000,0000,0000,,data dot because we want plot data dot
Dialogue: 0,0:09:53.57,0:09:58.31,Default,,0000,0000,0000,,PNG and our rules said that the way you
Dialogue: 0,0:09:55.97,0:10:00.29,Default,,0000,0000,0000,,go from that pattern to the dot file the
Dialogue: 0,0:09:58.31,0:10:03.17,Default,,0000,0000,0000,,dot that file is just by whatever
Dialogue: 0,0:10:00.29,0:10:05.54,Default,,0000,0000,0000,,follows plot so if we want plot - data
Dialogue: 0,0:10:03.17,0:10:07.61,Default,,0000,0000,0000,,then we want data dot that and then this
Dialogue: 0,0:10:05.54,0:10:09.05,Default,,0000,0000,0000,,file we're just gonna put in some linear
Dialogue: 0,0:10:07.61,0:10:13.97,Default,,0000,0000,0000,,coordinates because why not
Dialogue: 0,0:10:09.05,0:10:19.63,Default,,0000,0000,0000,,that's not linear all right and now what
Dialogue: 0,0:10:13.97,0:10:23.98,Default,,0000,0000,0000,,happens if we're gonna make well mmm
Dialogue: 0,0:10:19.63,0:10:28.64,Default,,0000,0000,0000,,okay so what just happened well make
Dialogue: 0,0:10:23.98,0:10:32.09,Default,,0000,0000,0000,,first ran plata py with the correct
Dialogue: 0,0:10:28.64,0:10:35.00,Default,,0000,0000,0000,,files to generate the PNG file and then
Dialogue: 0,0:10:32.09,0:10:36.32,Default,,0000,0000,0000,,it ran PDF latex paper dot text and all
Dialogue: 0,0:10:35.00,0:10:38.54,Default,,0000,0000,0000,,the stuff we see below is is the output
Dialogue: 0,0:10:36.32,0:10:40.22,Default,,0000,0000,0000,,from that tool if you wanted to we
Dialogue: 0,0:10:38.54,0:10:42.17,Default,,0000,0000,0000,,silence the effort from this tools we
Dialogue: 0,0:10:40.22,0:10:44.18,Default,,0000,0000,0000,,don't have to like have it mess with all
Dialogue: 0,0:10:42.17,0:10:45.47,Default,,0000,0000,0000,,our output but in general you notice
Dialogue: 0,0:10:44.18,0:10:47.51,Default,,0000,0000,0000,,that it ran the two commands then it
Dialogue: 0,0:10:45.47,0:10:50.24,Default,,0000,0000,0000,,write the random perhaps unsurprisingly
Dialogue: 0,0:10:47.51,0:10:51.71,Default,,0000,0000,0000,,in the right order and if we now do LS
Dialogue: 0,0:10:50.24,0:10:52.97,Default,,0000,0000,0000,,in the current directory we see that we
Dialogue: 0,0:10:51.71,0:10:56.90,Default,,0000,0000,0000,,have a bunch of files that were
Dialogue: 0,0:10:52.97,0:10:59.15,Default,,0000,0000,0000,,generated by PDF latex but in particular
Dialogue: 0,0:10:56.90,0:11:01.61,Default,,0000,0000,0000,,we have the PNG file which was generated
Dialogue: 0,0:10:59.15,0:11:04.37,Default,,0000,0000,0000,,and we have the paper dot PDF and if we
Dialogue: 0,0:11:01.61,0:11:05.84,Default,,0000,0000,0000,,open the paper - a PDF file we see that
Dialogue: 0,0:11:04.37,0:11:06.81,Default,,0000,0000,0000,,it has one image which has the straight
Dialogue: 0,0:11:05.84,0:11:08.67,Default,,0000,0000,0000,,line
Dialogue: 0,0:11:06.81,0:11:10.83,Default,,0000,0000,0000,,perhaps in and of itself not a very
Dialogue: 0,0:11:08.67,0:11:13.47,Default,,0000,0000,0000,,surprising or interesting result but
Dialogue: 0,0:11:10.83,0:11:16.53,Default,,0000,0000,0000,,where this gets really handy is I can do
Dialogue: 0,0:11:13.47,0:11:19.11,Default,,0000,0000,0000,,things like if I type make again make
Dialogue: 0,0:11:16.53,0:11:21.93,Default,,0000,0000,0000,,just says paper dot PDF is up to date it
Dialogue: 0,0:11:19.11,0:11:23.88,Default,,0000,0000,0000,,does no work whenever you run make it
Dialogue: 0,0:11:21.93,0:11:25.71,Default,,0000,0000,0000,,tries to do the minimal amount of work
Dialogue: 0,0:11:23.88,0:11:28.44,Default,,0000,0000,0000,,in order to produce whatever you ask it
Dialogue: 0,0:11:25.71,0:11:30.30,Default,,0000,0000,0000,,to produce in this case none of the
Dialogue: 0,0:11:28.44,0:11:32.49,Default,,0000,0000,0000,,dependencies have changed so there's no
Dialogue: 0,0:11:30.30,0:11:36.66,Default,,0000,0000,0000,,reason to rebuild the paper or to
Dialogue: 0,0:11:32.49,0:11:39.54,Default,,0000,0000,0000,,rebuild the plot if I now let's say I'm
Dialogue: 0,0:11:36.66,0:11:44.76,Default,,0000,0000,0000,,gonna edit paper dog texts I'm gonna add
Dialogue: 0,0:11:39.54,0:11:47.43,Default,,0000,0000,0000,,hello here an hour and make then if we
Dialogue: 0,0:11:44.76,0:11:49.29,Default,,0000,0000,0000,,scroll up we'll see it didn't run plot
Dialogue: 0,0:11:47.43,0:11:51.18,Default,,0000,0000,0000,,op py again because I didn't need to
Dialogue: 0,0:11:49.29,0:11:53.43,Default,,0000,0000,0000,,none of the dependencies change but it
Dialogue: 0,0:11:51.18,0:11:56.63,Default,,0000,0000,0000,,did run PDF latex again and indeed if we
Dialogue: 0,0:11:53.43,0:11:59.28,Default,,0000,0000,0000,,open the paper analysis hello over there
Dialogue: 0,0:11:56.63,0:12:02.31,Default,,0000,0000,0000,,on the other hand if I were to change
Dialogue: 0,0:11:59.28,0:12:07.29,Default,,0000,0000,0000,,say the data file and make this point 8
Dialogue: 0,0:12:02.31,0:12:09.21,Default,,0000,0000,0000,,an hour and make then now it plots again
Dialogue: 0,0:12:07.29,0:12:10.98,Default,,0000,0000,0000,,because the data changed and it
Dialogue: 0,0:12:09.21,0:12:13.86,Default,,0000,0000,0000,,regenerates the PDF because the plot
Dialogue: 0,0:12:10.98,0:12:17.13,Default,,0000,0000,0000,,changed and indeed the paper turns out
Dialogue: 0,0:12:13.86,0:12:18.99,Default,,0000,0000,0000,,the way we expected it to so that's not
Dialogue: 0,0:12:17.13,0:12:21.72,Default,,0000,0000,0000,,to say that this particular pipeline is
Dialogue: 0,0:12:18.99,0:12:23.78,Default,,0000,0000,0000,,very interesting because it's not it's
Dialogue: 0,0:12:21.72,0:12:26.85,Default,,0000,0000,0000,,only true very very straightforward
Dialogue: 0,0:12:23.78,0:12:28.53,Default,,0000,0000,0000,,targets and rules but this can come in
Dialogue: 0,0:12:26.85,0:12:30.63,Default,,0000,0000,0000,,really handy when you start building
Dialogue: 0,0:12:28.53,0:12:32.43,Default,,0000,0000,0000,,larger pieces of software or there might
Dialogue: 0,0:12:30.63,0:12:34.98,Default,,0000,0000,0000,,be dependencies you might even imagine
Dialogue: 0,0:12:32.43,0:12:37.56,Default,,0000,0000,0000,,that if you're writing a paper one of
Dialogue: 0,0:12:34.98,0:12:40.23,Default,,0000,0000,0000,,your targets might be producing this
Dialogue: 0,0:12:37.56,0:12:41.52,Default,,0000,0000,0000,,data file in the first place right so
Dialogue: 0,0:12:40.23,0:12:45.27,Default,,0000,0000,0000,,one of the makefile
Dialogue: 0,0:12:41.52,0:12:48.24,Default,,0000,0000,0000,,targets might be run my experiment right
Dialogue: 0,0:12:45.27,0:12:50.49,Default,,0000,0000,0000,,run my benchmark and stick the the data
Dialogue: 0,0:12:48.24,0:12:52.95,Default,,0000,0000,0000,,points that come out into this file and
Dialogue: 0,0:12:50.49,0:12:54.51,Default,,0000,0000,0000,,then plot the results and then and then
Dialogue: 0,0:12:52.95,0:12:57.60,Default,,0000,0000,0000,,and then and then all the way until you
Dialogue: 0,0:12:54.51,0:12:59.58,Default,,0000,0000,0000,,end up with a final paper and what's
Dialogue: 0,0:12:57.60,0:13:00.81,Default,,0000,0000,0000,,nice about this is first of all you
Dialogue: 0,0:12:59.58,0:13:02.28,Default,,0000,0000,0000,,don't have to remember all the commands
Dialogue: 0,0:13:00.81,0:13:05.25,Default,,0000,0000,0000,,to run you don't have to write them down
Dialogue: 0,0:13:02.28,0:13:08.00,Default,,0000,0000,0000,,anywhere but also the tool takes care of
Dialogue: 0,0:13:05.25,0:13:10.41,Default,,0000,0000,0000,,doing the minimal amount of work needed
Dialogue: 0,0:13:08.00,0:13:12.39,Default,,0000,0000,0000,,often you'll find things like they'll be
Dialogue: 0,0:13:10.41,0:13:14.61,Default,,0000,0000,0000,,too there'll be sub commands to make
Dialogue: 0,0:13:12.39,0:13:15.99,Default,,0000,0000,0000,,like make tests right which is going to
Dialogue: 0,0:13:14.61,0:13:19.38,Default,,0000,0000,0000,,compile your entire piece of software
Dialogue: 0,0:13:15.99,0:13:20.64,Default,,0000,0000,0000,,and also run the tests there might be
Dialogue: 0,0:13:19.38,0:13:23.19,Default,,0000,0000,0000,,things like make release
Dialogue: 0,0:13:20.64,0:13:25.35,Default,,0000,0000,0000,,which builds it with optimizations
Dialogue: 0,0:13:23.19,0:13:27.75,Default,,0000,0000,0000,,turned on and creates a tarball and
Dialogue: 0,0:13:25.35,0:13:29.46,Default,,0000,0000,0000,,uploads that somewhere right so it's
Dialogue: 0,0:13:27.75,0:13:31.23,Default,,0000,0000,0000,,gonna do the whole pipeline for you the
Dialogue: 0,0:13:29.46,0:13:33.21,Default,,0000,0000,0000,,idea is to reduce the effort that you
Dialogue: 0,0:13:31.23,0:13:40.32,Default,,0000,0000,0000,,have to do as any part of your build
Dialogue: 0,0:13:33.21,0:13:43.08,Default,,0000,0000,0000,,process now what we saw here was a very
Dialogue: 0,0:13:40.32,0:13:45.12,Default,,0000,0000,0000,,straightforward example of dependencies
Dialogue: 0,0:13:43.08,0:13:47.01,Default,,0000,0000,0000,,right so we saw here that you could
Dialogue: 0,0:13:45.12,0:13:48.54,Default,,0000,0000,0000,,declare files as dependencies but you
Dialogue: 0,0:13:47.01,0:13:50.31,Default,,0000,0000,0000,,Kosar declare sort of transitive
Dialogue: 0,0:13:48.54,0:13:51.72,Default,,0000,0000,0000,,dependencies right I depend on this
Dialogue: 0,0:13:50.31,0:13:54.14,Default,,0000,0000,0000,,thing which is generated by this other
Dialogue: 0,0:13:51.72,0:13:56.82,Default,,0000,0000,0000,,target very often when you work with
Dialogue: 0,0:13:54.14,0:14:00.30,Default,,0000,0000,0000,,dependencies in the in the larger area
Dialogue: 0,0:13:56.82,0:14:01.89,Default,,0000,0000,0000,,of software you'll find that your your
Dialogue: 0,0:14:00.30,0:14:04.14,Default,,0000,0000,0000,,system ends up having many different
Dialogue: 0,0:14:01.89,0:14:06.36,Default,,0000,0000,0000,,types of dependencies some of these are
Dialogue: 0,0:14:04.14,0:14:09.33,Default,,0000,0000,0000,,files like we saw here some of them are
Dialogue: 0,0:14:06.36,0:14:11.31,Default,,0000,0000,0000,,programs right like this sort of
Dialogue: 0,0:14:09.33,0:14:13.83,Default,,0000,0000,0000,,implicitly depends on Python being
Dialogue: 0,0:14:11.31,0:14:15.75,Default,,0000,0000,0000,,installed on my machine some of it might
Dialogue: 0,0:14:13.83,0:14:18.27,Default,,0000,0000,0000,,be libraries right you might depend on
Dialogue: 0,0:14:15.75,0:14:20.07,Default,,0000,0000,0000,,something like matplotlib which we
Dialogue: 0,0:14:18.27,0:14:22.47,Default,,0000,0000,0000,,depend on here some of them might be
Dialogue: 0,0:14:20.07,0:14:25.34,Default,,0000,0000,0000,,system libraries like open SSL or open
Dialogue: 0,0:14:22.47,0:14:28.80,Default,,0000,0000,0000,,SSH or like low-level crypto libraries
Dialogue: 0,0:14:25.34,0:14:30.75,Default,,0000,0000,0000,,and you don't necessarily declare all of
Dialogue: 0,0:14:28.80,0:14:32.61,Default,,0000,0000,0000,,them very often there's sort of an an
Dialogue: 0,0:14:30.75,0:14:35.28,Default,,0000,0000,0000,,assumption about what is installed on
Dialogue: 0,0:14:32.61,0:14:37.56,Default,,0000,0000,0000,,the given system what you'll find is
Dialogue: 0,0:14:35.28,0:14:39.18,Default,,0000,0000,0000,,that for most places where you have
Dialogue: 0,0:14:37.56,0:14:41.55,Default,,0000,0000,0000,,dependencies there are tools for
Dialogue: 0,0:14:39.18,0:14:44.13,Default,,0000,0000,0000,,managing those dependencies for you and
Dialogue: 0,0:14:41.55,0:14:45.69,Default,,0000,0000,0000,,very often these systems you might
Dialogue: 0,0:14:44.13,0:14:49.05,Default,,0000,0000,0000,,depend on are stored in what are known
Dialogue: 0,0:14:45.69,0:14:52.05,Default,,0000,0000,0000,,as repositories so repository is just a
Dialogue: 0,0:14:49.05,0:14:55.26,Default,,0000,0000,0000,,collection of things usually related
Dialogue: 0,0:14:52.05,0:14:57.21,Default,,0000,0000,0000,,that you can install that's basically
Dialogue: 0,0:14:55.26,0:14:58.47,Default,,0000,0000,0000,,all a repository is and you might be
Dialogue: 0,0:14:57.21,0:15:00.93,Default,,0000,0000,0000,,familiar with some of them already
Dialogue: 0,0:14:58.47,0:15:03.18,Default,,0000,0000,0000,,right so some examples of repositories
Dialogue: 0,0:15:00.93,0:15:05.94,Default,,0000,0000,0000,,are pi PI which is a well-known
Dialogue: 0,0:15:03.18,0:15:08.37,Default,,0000,0000,0000,,repository for Python packages rubygems
Dialogue: 0,0:15:05.94,0:15:11.34,Default,,0000,0000,0000,,which is similar for ruby crates or io
Dialogue: 0,0:15:08.37,0:15:13.89,Default,,0000,0000,0000,,for rust NPM for nodejs
Dialogue: 0,0:15:11.34,0:15:15.87,Default,,0000,0000,0000,,but other things the repositories too
Dialogue: 0,0:15:13.89,0:15:19.35,Default,,0000,0000,0000,,right like there are positives for
Dialogue: 0,0:15:15.87,0:15:22.02,Default,,0000,0000,0000,,cryptographic keys like key base there
Dialogue: 0,0:15:19.35,0:15:24.15,Default,,0000,0000,0000,,are repositories for system installed
Dialogue: 0,0:15:22.02,0:15:27.24,Default,,0000,0000,0000,,packages like if you ever use the apt
Dialogue: 0,0:15:24.15,0:15:28.80,Default,,0000,0000,0000,,tool in Ubuntu or in Debian you are
Dialogue: 0,0:15:27.24,0:15:30.81,Default,,0000,0000,0000,,interacting with a package repository
Dialogue: 0,0:15:28.80,0:15:32.97,Default,,0000,0000,0000,,where people who have written like
Dialogue: 0,0:15:30.81,0:15:34.67,Default,,0000,0000,0000,,programs and libraries upload them so
Dialogue: 0,0:15:32.97,0:15:37.74,Default,,0000,0000,0000,,that you can then install them
Dialogue: 0,0:15:34.67,0:15:40.20,Default,,0000,0000,0000,,similarly you might have repositories
Dialogue: 0,0:15:37.74,0:15:42.03,Default,,0000,0000,0000,,are entirely open right so the Ubuntu
Dialogue: 0,0:15:40.20,0:15:44.82,Default,,0000,0000,0000,,repositories for example are usually
Dialogue: 0,0:15:42.03,0:15:46.38,Default,,0000,0000,0000,,provided by the Ubuntu developers but in
Dialogue: 0,0:15:44.82,0:15:47.43,Default,,0000,0000,0000,,Arch Linux there might there is
Dialogue: 0,0:15:46.38,0:15:49.59,Default,,0000,0000,0000,,something called the arch user
Dialogue: 0,0:15:47.43,0:15:51.78,Default,,0000,0000,0000,,repository where users can just share
Dialogue: 0,0:15:49.59,0:15:53.37,Default,,0000,0000,0000,,their own libraries and their own
Dialogue: 0,0:15:51.78,0:15:55.44,Default,,0000,0000,0000,,packages themselves. Very often,
Dialogue: 0,0:15:53.37,0:15:58.26,Default,,0000,0000,0000,,repositories are either sort of managed
Dialogue: 0,0:15:55.44,0:15:59.79,Default,,0000,0000,0000,,or they are just entirely open and you
Dialogue: 0,0:15:58.26,0:16:01.98,Default,,0000,0000,0000,,should often be aware of this because if
Dialogue: 0,0:15:59.79,0:16:04.05,Default,,0000,0000,0000,,you're using an entirely open repository
Dialogue: 0,0:16:01.98,0:16:05.67,Default,,0000,0000,0000,,maybe the security guarantees you get
Dialogue: 0,0:16:04.05,0:16:09.06,Default,,0000,0000,0000,,from that are less than what you get in
Dialogue: 0,0:16:05.67,0:16:10.95,Default,,0000,0000,0000,,a controlled repository one thing you'll
Dialogue: 0,0:16:09.06,0:16:13.79,Default,,0000,0000,0000,,notice if you start using repositories
Dialogue: 0,0:16:10.95,0:16:17.04,Default,,0000,0000,0000,,is a very often software is versioned
Dialogue: 0,0:16:13.79,0:16:18.18,Default,,0000,0000,0000,,and what I mean by version well you
Dialogue: 0,0:16:17.04,0:16:20.19,Default,,0000,0000,0000,,might have seen this for stuff like
Dialogue: 0,0:16:18.18,0:16:24.66,Default,,0000,0000,0000,,browsers right where there might be
Dialogue: 0,0:16:20.19,0:16:33.60,Default,,0000,0000,0000,,something like starting like Chrome
Dialogue: 0,0:16:24.66,0:16:38.43,Default,,0000,0000,0000,,version 64 dot zero dot two zero one 903
Dialogue: 0,0:16:33.60,0:16:44.16,Default,,0000,0000,0000,,24 right this is a version number it
Dialogue: 0,0:16:38.43,0:16:45.99,Default,,0000,0000,0000,,might there's a dot here this is one
Dialogue: 0,0:16:44.16,0:16:50.40,Default,,0000,0000,0000,,kind of version number. But, sometimes, if
Dialogue: 0,0:16:45.99,0:16:52.08,Default,,0000,0000,0000,,you start, I don't know, like Photoshop or
Dialogue: 0,0:16:50.40,0:16:54.35,Default,,0000,0000,0000,,you start any other tool, there might be
Dialogue: 0,0:16:52.08,0:16:58.17,Default,,0000,0000,0000,,other kind of versions that are, like,
Dialogue: 0,0:16:54.35,0:16:59.94,Default,,0000,0000,0000,,8.1 dot seven right these version
Dialogue: 0,0:16:58.17,0:17:01.47,Default,,0000,0000,0000,,numbers are usually numerical but not
Dialogue: 0,0:16:59.94,0:17:03.18,Default,,0000,0000,0000,,always sometimes they have hashes in
Dialogue: 0,0:17:01.47,0:17:05.01,Default,,0000,0000,0000,,them for example to refer to git commits
Dialogue: 0,0:17:03.18,0:17:07.29,Default,,0000,0000,0000,,but you might wonder why do we have
Dialogue: 0,0:17:05.01,0:17:08.73,Default,,0000,0000,0000,,these why is it even important that you
Dialogue: 0,0:17:07.29,0:17:11.43,Default,,0000,0000,0000,,add a number to software that you
Dialogue: 0,0:17:08.73,0:17:15.96,Default,,0000,0000,0000,,release the primary reason for this is
Dialogue: 0,0:17:11.43,0:17:19.11,Default,,0000,0000,0000,,because it enables me to know whether my
Dialogue: 0,0:17:15.96,0:17:21.30,Default,,0000,0000,0000,,software would break imagine that I have
Dialogue: 0,0:17:19.11,0:17:25.32,Default,,0000,0000,0000,,a dependency on a library that Jose has
Dialogue: 0,0:17:21.30,0:17:26.64,Default,,0000,0000,0000,,written right and Jose is constantly
Dialogue: 0,0:17:25.32,0:17:28.35,Default,,0000,0000,0000,,doing changes to his library because he
Dialogue: 0,0:17:26.64,0:17:29.91,Default,,0000,0000,0000,,wants to make it better and he decides
Dialogue: 0,0:17:28.35,0:17:32.13,Default,,0000,0000,0000,,that one of the functions that his
Dialogue: 0,0:17:29.91,0:17:35.25,Default,,0000,0000,0000,,library exposes has a bad name so he
Dialogue: 0,0:17:32.13,0:17:38.82,Default,,0000,0000,0000,,renames it my software suddenly stops
Dialogue: 0,0:17:35.25,0:17:40.56,Default,,0000,0000,0000,,working right because I my library calls
Dialogue: 0,0:17:38.82,0:17:43.02,Default,,0000,0000,0000,,a function on Jose's library but that
Dialogue: 0,0:17:40.56,0:17:44.67,Default,,0000,0000,0000,,function no longer exists depending on
Dialogue: 0,0:17:43.02,0:17:48.24,Default,,0000,0000,0000,,which version people have installed of
Dialogue: 0,0:17:44.67,0:17:50.25,Default,,0000,0000,0000,,Jose's library versions helps
Dialogue: 0,0:17:48.24,0:17:52.50,Default,,0000,0000,0000,,because I can say I depend on this
Dialogue: 0,0:17:50.25,0:17:54.72,Default,,0000,0000,0000,,version of Jose's library and there has
Dialogue: 0,0:17:52.50,0:17:58.23,Default,,0000,0000,0000,,to be some rules around what is Jose
Dialogue: 0,0:17:54.72,0:18:00.30,Default,,0000,0000,0000,,allowed to do within a given version if
Dialogue: 0,0:17:58.23,0:18:02.34,Default,,0000,0000,0000,,he makes a change that I can no longer
Dialogue: 0,0:18:00.30,0:18:03.90,Default,,0000,0000,0000,,rely on his version has to change in
Dialogue: 0,0:18:02.34,0:18:06.75,Default,,0000,0000,0000,,some way
Dialogue: 0,0:18:03.90,0:18:09.78,Default,,0000,0000,0000,,there are many thoughts on exactly how
Dialogue: 0,0:18:06.75,0:18:11.73,Default,,0000,0000,0000,,this should work like what are the rules
Dialogue: 0,0:18:09.78,0:18:14.46,Default,,0000,0000,0000,,for publishing new versions how do they
Dialogue: 0,0:18:11.73,0:18:17.97,Default,,0000,0000,0000,,change the version numbers um some of
Dialogue: 0,0:18:14.46,0:18:19.71,Default,,0000,0000,0000,,them are just dictated by time so for
Dialogue: 0,0:18:17.97,0:18:22.02,Default,,0000,0000,0000,,example if you look at browsers they
Dialogue: 0,0:18:19.71,0:18:24.33,Default,,0000,0000,0000,,very often have time versions that look
Dialogue: 0,0:18:22.02,0:18:26.13,Default,,0000,0000,0000,,like this they have a version number on
Dialogue: 0,0:18:24.33,0:18:28.53,Default,,0000,0000,0000,,the far left that's just like which
Dialogue: 0,0:18:26.13,0:18:30.41,Default,,0000,0000,0000,,release and then they have sort of an
Dialogue: 0,0:18:28.53,0:18:32.85,Default,,0000,0000,0000,,incremental number that is usually zero
Dialogue: 0,0:18:30.41,0:18:37.20,Default,,0000,0000,0000,,and then they have a date at the end
Dialogue: 0,0:18:32.85,0:18:40.23,Default,,0000,0000,0000,,right so this is March 24th 2019 for
Dialogue: 0,0:18:37.20,0:18:44.67,Default,,0000,0000,0000,,some reason and usually that will
Dialogue: 0,0:18:40.23,0:18:48.09,Default,,0000,0000,0000,,indicate that this is version 64 of
Dialogue: 0,0:18:44.67,0:18:50.55,Default,,0000,0000,0000,,Firefox from this date and then if they
Dialogue: 0,0:18:48.09,0:18:51.96,Default,,0000,0000,0000,,release sort of patches or hot fixes for
Dialogue: 0,0:18:50.55,0:18:54.18,Default,,0000,0000,0000,,security bugs they might increment the
Dialogue: 0,0:18:51.96,0:18:58.80,Default,,0000,0000,0000,,date but keep the version of the at the
Dialogue: 0,0:18:54.18,0:19:01.05,Default,,0000,0000,0000,,left the same and people have strong
Dialogue: 0,0:18:58.80,0:19:03.18,Default,,0000,0000,0000,,strong opinions on exactly what the
Dialogue: 0,0:19:01.05,0:19:05.43,Default,,0000,0000,0000,,scheme should be and you sort of depend
Dialogue: 0,0:19:03.18,0:19:08.07,Default,,0000,0000,0000,,on knowing what schemes other people use
Dialogue: 0,0:19:05.43,0:19:09.69,Default,,0000,0000,0000,,right if I don't know what scheme Jose
Dialogue: 0,0:19:08.07,0:19:11.73,Default,,0000,0000,0000,,is using for changing his versions
Dialogue: 0,0:19:09.69,0:19:14.43,Default,,0000,0000,0000,,maybe I just have to say you have to run
Dialogue: 0,0:19:11.73,0:19:17.55,Default,,0000,0000,0000,,like eight one seven of Jose's software
Dialogue: 0,0:19:14.43,0:19:19.23,Default,,0000,0000,0000,,otherwise I cannot build my software but
Dialogue: 0,0:19:17.55,0:19:21.69,Default,,0000,0000,0000,,this is a problem, too, right?
Dialogue: 0,0:19:19.23,0:19:23.61,Default,,0000,0000,0000,,Imagine that, Jose, as a responsible
Dialogue: 0,0:19:21.69,0:19:26.88,Default,,0000,0000,0000,,developer of his library, and he finds
Dialogue: 0,0:19:23.61,0:19:29.19,Default,,0000,0000,0000,,the security bug and he fixes it but it
Dialogue: 0,0:19:26.88,0:19:31.26,Default,,0000,0000,0000,,doesn't change the external interfaces
Dialogue: 0,0:19:29.19,0:19:34.08,Default,,0000,0000,0000,,library no functions changed no types
Dialogue: 0,0:19:31.26,0:19:37.14,Default,,0000,0000,0000,,change then I want people to be building
Dialogue: 0,0:19:34.08,0:19:39.42,Default,,0000,0000,0000,,my software with his new version and it
Dialogue: 0,0:19:37.14,0:19:40.83,Default,,0000,0000,0000,,just so happens that building mine works
Dialogue: 0,0:19:39.42,0:19:42.63,Default,,0000,0000,0000,,just fine with his new version because
Dialogue: 0,0:19:40.83,0:19:47.34,Default,,0000,0000,0000,,that particular version didn't change
Dialogue: 0,0:19:42.63,0:19:48.75,Default,,0000,0000,0000,,anything I depended on so one attempted
Dialogue: 0,0:19:47.34,0:19:51.27,Default,,0000,0000,0000,,solution to this is something called
Dialogue: 0,0:19:48.75,0:19:53.40,Default,,0000,0000,0000,,semantic versioning. So, in semantic
Dialogue: 0,0:19:51.27,0:19:55.35,Default,,0000,0000,0000,,versioning, we give each of the numbers
Dialogue: 0,0:19:53.40,0:19:57.48,Default,,0000,0000,0000,,separated by dots in a version number, a
Dialogue: 0,0:19:55.35,0:19:59.70,Default,,0000,0000,0000,,particular meaning. And, we give a
Dialogue: 0,0:19:57.48,0:20:01.00,Default,,0000,0000,0000,,contract for when you have to increment
Dialogue: 0,0:19:59.70,0:20:06.73,Default,,0000,0000,0000,,the different numbers
Dialogue: 0,0:20:01.00,0:20:14.91,Default,,0000,0000,0000,,in particular in semantic versioning we
Dialogue: 0,0:20:06.73,0:20:20.26,Default,,0000,0000,0000,,call this the major version we call this
Dialogue: 0,0:20:14.91,0:20:25.75,Default,,0000,0000,0000,,the minor version and we call this the
Dialogue: 0,0:20:20.26,0:20:29.58,Default,,0000,0000,0000,,patch version and the rules around this
Dialogue: 0,0:20:25.75,0:20:33.25,Default,,0000,0000,0000,,are as follows if you make a change to
Dialogue: 0,0:20:29.58,0:20:35.53,Default,,0000,0000,0000,,whatever your software is and and the
Dialogue: 0,0:20:33.25,0:20:38.14,Default,,0000,0000,0000,,change you made is entirely backwards
Dialogue: 0,0:20:35.53,0:20:40.69,Default,,0000,0000,0000,,compatible right like it does not add
Dialogue: 0,0:20:38.14,0:20:43.57,Default,,0000,0000,0000,,anything it does not remove anything it
Dialogue: 0,0:20:40.69,0:20:47.29,Default,,0000,0000,0000,,does not rename anything externally it
Dialogue: 0,0:20:43.57,0:20:49.75,Default,,0000,0000,0000,,is as if nothing changed then you only
Dialogue: 0,0:20:47.29,0:20:52.00,Default,,0000,0000,0000,,increment the patch number nothing else
Dialogue: 0,0:20:49.75,0:20:54.85,Default,,0000,0000,0000,,so usually security fixes for example
Dialogue: 0,0:20:52.00,0:20:58.30,Default,,0000,0000,0000,,will increment the patch number if you
Dialogue: 0,0:20:54.85,0:20:59.35,Default,,0000,0000,0000,,add something to your library I'm just
Dialogue: 0,0:20:58.30,0:21:01.09,Default,,0000,0000,0000,,gonna call them libraries because
Dialogue: 0,0:20:59.35,0:21:03.94,Default,,0000,0000,0000,,usually libraries are the things where
Dialogue: 0,0:21:01.09,0:21:05.59,Default,,0000,0000,0000,,this matters so for a library if you add
Dialogue: 0,0:21:03.94,0:21:07.93,Default,,0000,0000,0000,,something to the library you increment
Dialogue: 0,0:21:05.59,0:21:11.14,Default,,0000,0000,0000,,the minor version and you set the patch
Dialogue: 0,0:21:07.93,0:21:13.48,Default,,0000,0000,0000,,to zero so in this case if we were to do
Dialogue: 0,0:21:11.14,0:21:15.55,Default,,0000,0000,0000,,a minor release the next minor release
Dialogue: 0,0:21:13.48,0:21:19.03,Default,,0000,0000,0000,,version number would be eight to zero
Dialogue: 0,0:21:15.55,0:21:22.51,Default,,0000,0000,0000,,and the reason we do this is because I
Dialogue: 0,0:21:19.03,0:21:26.26,Default,,0000,0000,0000,,might have a dependency on a feature the
Dialogue: 0,0:21:22.51,0:21:28.39,Default,,0000,0000,0000,,josè added in a 2-0 which means you
Dialogue: 0,0:21:26.26,0:21:30.43,Default,,0000,0000,0000,,can't build my software with eight one
Dialogue: 0,0:21:28.39,0:21:32.92,Default,,0000,0000,0000,,seven that would not be okay
Dialogue: 0,0:21:30.43,0:21:34.33,Default,,0000,0000,0000,,even though if you if I had written it
Dialogue: 0,0:21:32.92,0:21:36.54,Default,,0000,0000,0000,,towards eight one seven you could run it
Dialogue: 0,0:21:34.33,0:21:38.62,Default,,0000,0000,0000,,with a 2-0 the reverse is not true
Dialogue: 0,0:21:36.54,0:21:42.31,Default,,0000,0000,0000,,because it might not have been added yet
Dialogue: 0,0:21:38.62,0:21:43.84,Default,,0000,0000,0000,,and then finally the major version you
Dialogue: 0,0:21:42.31,0:21:48.58,Default,,0000,0000,0000,,increment if you make a backwards
Dialogue: 0,0:21:43.84,0:21:50.80,Default,,0000,0000,0000,,incompatible change where if my software
Dialogue: 0,0:21:48.58,0:21:52.96,Default,,0000,0000,0000,,used to work with whatever version you
Dialogue: 0,0:21:50.80,0:21:54.40,Default,,0000,0000,0000,,had and then you make a change that
Dialogue: 0,0:21:52.96,0:21:56.53,Default,,0000,0000,0000,,means that my software might no longer
Dialogue: 0,0:21:54.40,0:21:58.48,Default,,0000,0000,0000,,work such as removing a function or
Dialogue: 0,0:21:56.53,0:22:00.70,Default,,0000,0000,0000,,renaming it then you increment the major
Dialogue: 0,0:21:58.48,0:22:02.89,Default,,0000,0000,0000,,version and set minor and patch to zero
Dialogue: 0,0:22:00.70,0:22:07.18,Default,,0000,0000,0000,,so the next major version here would be
Dialogue: 0,0:22:02.89,0:22:09.82,Default,,0000,0000,0000,,nine zero zero taken together these
Dialogue: 0,0:22:07.18,0:22:11.74,Default,,0000,0000,0000,,allow us to do really nice things when
Dialogue: 0,0:22:09.82,0:22:14.05,Default,,0000,0000,0000,,setting what our dependencies are in
Dialogue: 0,0:22:11.74,0:22:15.82,Default,,0000,0000,0000,,particular if I depend on a
Dialogue: 0,0:22:14.05,0:22:18.37,Default,,0000,0000,0000,,particular version of someone's library
Dialogue: 0,0:22:15.82,0:22:20.59,Default,,0000,0000,0000,,rather than saying it has to be exactly
Dialogue: 0,0:22:18.37,0:22:23.28,Default,,0000,0000,0000,,this version what I'm really saying is
Dialogue: 0,0:22:20.59,0:22:27.79,Default,,0000,0000,0000,,it has to be the same major version and
Dialogue: 0,0:22:23.28,0:22:30.70,Default,,0000,0000,0000,,at least the same minor version and the
Dialogue: 0,0:22:27.79,0:22:32.61,Default,,0000,0000,0000,,patch can be whatever this means that if
Dialogue: 0,0:22:30.70,0:22:36.13,Default,,0000,0000,0000,,I have a dependency on Jose software
Dialogue: 0,0:22:32.61,0:22:39.25,Default,,0000,0000,0000,,then any later release that is still
Dialogue: 0,0:22:36.13,0:22:42.09,Default,,0000,0000,0000,,within the same major is fine that
Dialogue: 0,0:22:39.25,0:22:45.06,Default,,0000,0000,0000,,includes keep in mind an earlier version
Dialogue: 0,0:22:42.09,0:22:47.26,Default,,0000,0000,0000,,assuming that the minor is the same
Dialogue: 0,0:22:45.06,0:22:49.21,Default,,0000,0000,0000,,imagine that you are saw on some older
Dialogue: 0,0:22:47.26,0:22:52.06,Default,,0000,0000,0000,,computer that has like version eight one
Dialogue: 0,0:22:49.21,0:22:53.83,Default,,0000,0000,0000,,three in theory my software should work
Dialogue: 0,0:22:52.06,0:22:56.53,Default,,0000,0000,0000,,just fine with eight one three as well
Dialogue: 0,0:22:53.83,0:22:58.03,Default,,0000,0000,0000,,it might have whatever bug the Jose
Dialogue: 0,0:22:56.53,0:23:00.16,Default,,0000,0000,0000,,fixed in between like whatever security
Dialogue: 0,0:22:58.03,0:23:02.32,Default,,0000,0000,0000,,issue but this has the nice property
Dialogue: 0,0:23:00.16,0:23:03.73,Default,,0000,0000,0000,,that now you can share dependencies
Dialogue: 0,0:23:02.32,0:23:05.68,Default,,0000,0000,0000,,between many different pieces of
Dialogue: 0,0:23:03.73,0:23:08.95,Default,,0000,0000,0000,,software on your machine if you have
Dialogue: 0,0:23:05.68,0:23:10.57,Default,,0000,0000,0000,,version eight-30 installed and there are
Dialogue: 0,0:23:08.95,0:23:12.16,Default,,0000,0000,0000,,bunch of different software that like
Dialogue: 0,0:23:10.57,0:23:14.26,Default,,0000,0000,0000,,one requires eight one seven one
Dialogue: 0,0:23:12.16,0:23:16.72,Default,,0000,0000,0000,,requires eight two four one requires
Dialogue: 0,0:23:14.26,0:23:18.28,Default,,0000,0000,0000,,eight zero one all of them can use the
Dialogue: 0,0:23:16.72,0:23:23.14,Default,,0000,0000,0000,,same version of that dependencies you
Dialogue: 0,0:23:18.28,0:23:26.86,Default,,0000,0000,0000,,only needed installed once one of the
Dialogue: 0,0:23:23.14,0:23:28.78,Default,,0000,0000,0000,,most common or one of the most familiar
Dialogue: 0,0:23:26.86,0:23:30.52,Default,,0000,0000,0000,,perhaps examples of this kind of
Dialogue: 0,0:23:28.78,0:23:33.46,Default,,0000,0000,0000,,semantic versioning is if you look at
Dialogue: 0,0:23:30.52,0:23:35.71,Default,,0000,0000,0000,,the Python versioning so many of you may
Dialogue: 0,0:23:33.46,0:23:38.29,Default,,0000,0000,0000,,have come across this where python 3 and
Dialogue: 0,0:23:35.71,0:23:40.15,Default,,0000,0000,0000,,python 2 are not compatible with one
Dialogue: 0,0:23:38.29,0:23:43.33,Default,,0000,0000,0000,,another they're not backwards compatible
Dialogue: 0,0:23:40.15,0:23:46.33,Default,,0000,0000,0000,,if you write code in Python 2 you try to
Dialogue: 0,0:23:43.33,0:23:48.25,Default,,0000,0000,0000,,run in Python 3 it might not work there
Dialogue: 0,0:23:46.33,0:23:51.21,Default,,0000,0000,0000,,are some cases where it will but that is
Dialogue: 0,0:23:48.25,0:23:53.38,Default,,0000,0000,0000,,more accidental than anything else and
Dialogue: 0,0:23:51.21,0:23:56.29,Default,,0000,0000,0000,,Python actually follows semantic
Dialogue: 0,0:23:53.38,0:23:59.02,Default,,0000,0000,0000,,versioning at least mostly and so if you
Dialogue: 0,0:23:56.29,0:24:02.38,Default,,0000,0000,0000,,write software that runs on Python 3.5
Dialogue: 0,0:23:59.02,0:24:05.05,Default,,0000,0000,0000,,then it should also work in 3.6 3.7 and
Dialogue: 0,0:24:02.38,0:24:07.48,Default,,0000,0000,0000,,3.8 it will not necessarily work in
Dialogue: 0,0:24:05.05,0:24:10.30,Default,,0000,0000,0000,,Python 4 although that will hopefully be
Dialogue: 0,0:24:07.48,0:24:13.63,Default,,0000,0000,0000,,a long time away but if you write code
Dialogue: 0,0:24:10.30,0:24:17.59,Default,,0000,0000,0000,,for Python 3.5 it will it will possibly
Dialogue: 0,0:24:13.63,0:24:19.57,Default,,0000,0000,0000,,not run on Python 3.4 so one thing you
Dialogue: 0,0:24:17.59,0:24:21.91,Default,,0000,0000,0000,,will see many software projects do is
Dialogue: 0,0:24:19.57,0:24:23.68,Default,,0000,0000,0000,,they try to bring the version
Dialogue: 0,0:24:21.91,0:24:26.61,Default,,0000,0000,0000,,requirements they have as low as
Dialogue: 0,0:24:23.68,0:24:29.52,Default,,0000,0000,0000,,possible if you can depend on major
Dialogue: 0,0:24:26.61,0:24:31.44,Default,,0000,0000,0000,,and then minor in patch zero zero that
Dialogue: 0,0:24:29.52,0:24:33.99,Default,,0000,0000,0000,,is the best possible dependency you can
Dialogue: 0,0:24:31.44,0:24:36.21,Default,,0000,0000,0000,,have because it is completely liberal as
Dialogue: 0,0:24:33.99,0:24:38.16,Default,,0000,0000,0000,,to which version of that major you're
Dialogue: 0,0:24:36.21,0:24:39.72,Default,,0000,0000,0000,,depending on sometimes this is hard
Dialogue: 0,0:24:38.16,0:24:41.76,Default,,0000,0000,0000,,right sometimes you genuinely need a
Dialogue: 0,0:24:39.72,0:24:43.59,Default,,0000,0000,0000,,feature that was added but the lower you
Dialogue: 0,0:24:41.76,0:24:47.87,Default,,0000,0000,0000,,can get the better it is for those who
Dialogue: 0,0:24:43.59,0:24:47.87,Default,,0000,0000,0000,,want to depend on your software in turn
Dialogue: 0,0:24:48.68,0:24:52.71,Default,,0000,0000,0000,,when working with these sort of
Dialogue: 0,0:24:50.82,0:24:55.02,Default,,0000,0000,0000,,dependency management systems or in with
Dialogue: 0,0:24:52.71,0:24:57.66,Default,,0000,0000,0000,,versioning in general you'll often come
Dialogue: 0,0:24:55.02,0:24:59.73,Default,,0000,0000,0000,,across this notion of lock files you
Dialogue: 0,0:24:57.66,0:25:01.38,Default,,0000,0000,0000,,might have seen this where like you try
Dialogue: 0,0:24:59.73,0:25:04.14,Default,,0000,0000,0000,,to do something and it says like cannot
Dialogue: 0,0:25:01.38,0:25:06.48,Default,,0000,0000,0000,,reconcile versions or you get an error
Dialogue: 0,0:25:04.14,0:25:08.97,Default,,0000,0000,0000,,like lock file already exists these are
Dialogue: 0,0:25:06.48,0:25:11.16,Default,,0000,0000,0000,,often somewhat different topics but in
Dialogue: 0,0:25:08.97,0:25:12.99,Default,,0000,0000,0000,,general the notion of a lock file is to
Dialogue: 0,0:25:11.16,0:25:16.23,Default,,0000,0000,0000,,make sure that you don't accidentally
Dialogue: 0,0:25:12.99,0:25:18.54,Default,,0000,0000,0000,,update something the lock file at its
Dialogue: 0,0:25:16.23,0:25:20.31,Default,,0000,0000,0000,,core is really just a list of your
Dialogue: 0,0:25:18.54,0:25:23.34,Default,,0000,0000,0000,,dependencies and which version of them
Dialogue: 0,0:25:20.31,0:25:25.11,Default,,0000,0000,0000,,you are currently using right so my
Dialogue: 0,0:25:23.34,0:25:27.42,Default,,0000,0000,0000,,version string might be eight one seven
Dialogue: 0,0:25:25.11,0:25:30.29,Default,,0000,0000,0000,,and the latest version like on the
Dialogue: 0,0:25:27.42,0:25:32.88,Default,,0000,0000,0000,,internet somewhere might be a three zero
Dialogue: 0,0:25:30.29,0:25:34.77,Default,,0000,0000,0000,,but whatever is installed on my system
Dialogue: 0,0:25:32.88,0:25:36.15,Default,,0000,0000,0000,,is not necessarily one of those two it
Dialogue: 0,0:25:34.77,0:25:39.03,Default,,0000,0000,0000,,might be like eight two four or
Dialogue: 0,0:25:36.15,0:25:42.03,Default,,0000,0000,0000,,something like that and the lock file
Dialogue: 0,0:25:39.03,0:25:45.18,Default,,0000,0000,0000,,will then say dependency josè version
Dialogue: 0,0:25:42.03,0:25:48.39,Default,,0000,0000,0000,,eight to four and the reason you want to
Dialogue: 0,0:25:45.18,0:25:51.48,Default,,0000,0000,0000,,lock file there can be many one of them
Dialogue: 0,0:25:48.39,0:25:55.11,Default,,0000,0000,0000,,is that you might want your builds to be
Dialogue: 0,0:25:51.48,0:25:57.81,Default,,0000,0000,0000,,fast if every single time you try to
Dialogue: 0,0:25:55.11,0:25:59.16,Default,,0000,0000,0000,,build your project whatever tool you
Dialogue: 0,0:25:57.81,0:26:01.14,Default,,0000,0000,0000,,were using download the latest version
Dialogue: 0,0:25:59.16,0:26:02.97,Default,,0000,0000,0000,,and then compile it and then compile
Dialogue: 0,0:26:01.14,0:26:04.95,Default,,0000,0000,0000,,your thing you might wait for a really
Dialogue: 0,0:26:02.97,0:26:06.60,Default,,0000,0000,0000,,long time each time depending on the
Dialogue: 0,0:26:04.95,0:26:09.87,Default,,0000,0000,0000,,release cycle of your dependencies if
Dialogue: 0,0:26:06.60,0:26:10.47,Default,,0000,0000,0000,,you use a lock file then unless the
Dialogue: 0,0:26:09.87,0:26:12.03,Default,,0000,0000,0000,,version
Dialogue: 0,0:26:10.47,0:26:14.01,Default,,0000,0000,0000,,unless you've updated the version in
Dialogue: 0,0:26:12.03,0:26:15.96,Default,,0000,0000,0000,,your lock file it'll just use whatever
Dialogue: 0,0:26:14.01,0:26:19.08,Default,,0000,0000,0000,,it built previously for that dependency
Dialogue: 0,0:26:15.96,0:26:21.75,Default,,0000,0000,0000,,and your sort of development cycle can
Dialogue: 0,0:26:19.08,0:26:24.98,Default,,0000,0000,0000,,be a lot faster another reason to use
Dialogue: 0,0:26:21.75,0:26:27.48,Default,,0000,0000,0000,,lock files is to get reproducible builds
Dialogue: 0,0:26:24.98,0:26:29.76,Default,,0000,0000,0000,,imagine that I produce some kind of
Dialogue: 0,0:26:27.48,0:26:32.88,Default,,0000,0000,0000,,security related software and I very
Dialogue: 0,0:26:29.76,0:26:35.22,Default,,0000,0000,0000,,carefully audited my dependencies and I
Dialogue: 0,0:26:32.88,0:26:38.88,Default,,0000,0000,0000,,produce like a signed binary of like
Dialogue: 0,0:26:35.22,0:26:39.64,Default,,0000,0000,0000,,here is thus like a sworn statement for
Dialogue: 0,0:26:38.88,0:26:43.00,Default,,0000,0000,0000,,me that this
Dialogue: 0,0:26:39.64,0:26:45.82,Default,,0000,0000,0000,,version is secure if I didn't include a
Dialogue: 0,0:26:43.00,0:26:48.10,Default,,0000,0000,0000,,lock file then by the time someone else
Dialogue: 0,0:26:45.82,0:26:49.72,Default,,0000,0000,0000,,installs my program they might get a
Dialogue: 0,0:26:48.10,0:26:51.31,Default,,0000,0000,0000,,later version of their pendency and
Dialogue: 0,0:26:49.72,0:26:53.53,Default,,0000,0000,0000,,maybe that later version as I've been
Dialogue: 0,0:26:51.31,0:26:55.30,Default,,0000,0000,0000,,hacked somehow or just has some other
Dialogue: 0,0:26:53.53,0:26:58.18,Default,,0000,0000,0000,,security vulnerability that I haven't
Dialogue: 0,0:26:55.30,0:27:00.64,Default,,0000,0000,0000,,had a chance to look at yet right and a
Dialogue: 0,0:26:58.18,0:27:03.49,Default,,0000,0000,0000,,lock file basically allows me to freeze
Dialogue: 0,0:27:00.64,0:27:06.70,Default,,0000,0000,0000,,the ecosystem as of this version that I
Dialogue: 0,0:27:03.49,0:27:08.83,Default,,0000,0000,0000,,have checked the extreme version of this
Dialogue: 0,0:27:06.70,0:27:11.14,Default,,0000,0000,0000,,is something called ven during when you
Dialogue: 0,0:27:08.83,0:27:13.63,Default,,0000,0000,0000,,vendor your dependencies it really just
Dialogue: 0,0:27:11.14,0:27:15.52,Default,,0000,0000,0000,,mean you copy/paste of them ven during
Dialogue: 0,0:27:13.63,0:27:18.45,Default,,0000,0000,0000,,means take whatever dependency you care
Dialogue: 0,0:27:15.52,0:27:21.94,Default,,0000,0000,0000,,about and copy it into your project
Dialogue: 0,0:27:18.45,0:27:24.22,Default,,0000,0000,0000,,because that way you are entirely sure
Dialogue: 0,0:27:21.94,0:27:26.41,Default,,0000,0000,0000,,that you will get that version of that
Dialogue: 0,0:27:24.22,0:27:28.03,Default,,0000,0000,0000,,dependency it also means that you can
Dialogue: 0,0:27:26.41,0:27:29.98,Default,,0000,0000,0000,,like make modifications to it on your
Dialogue: 0,0:27:28.03,0:27:31.96,Default,,0000,0000,0000,,own but it has the downsides that now
Dialogue: 0,0:27:29.98,0:27:34.54,Default,,0000,0000,0000,,you no longer get these benefits of
Dialogue: 0,0:27:31.96,0:27:36.34,Default,,0000,0000,0000,,versioning right you no longer have the
Dialogue: 0,0:27:34.54,0:27:38.74,Default,,0000,0000,0000,,advantage that if there are newer
Dialogue: 0,0:27:36.34,0:27:40.54,Default,,0000,0000,0000,,releases of that software your users
Dialogue: 0,0:27:38.74,0:27:42.37,Default,,0000,0000,0000,,might get them automatically like for
Dialogue: 0,0:27:40.54,0:27:49.18,Default,,0000,0000,0000,,example when Hosea fixes his security
Dialogue: 0,0:27:42.37,0:27:51.52,Default,,0000,0000,0000,,issues not that he has any of course one
Dialogue: 0,0:27:49.18,0:27:53.56,Default,,0000,0000,0000,,thing you'll notice is that when talking
Dialogue: 0,0:27:51.52,0:27:56.26,Default,,0000,0000,0000,,about this I've been talking about sort
Dialogue: 0,0:27:53.56,0:27:59.08,Default,,0000,0000,0000,,of bigger processes around your systems
Dialogue: 0,0:27:56.26,0:28:01.00,Default,,0000,0000,0000,,these are things like testing they're
Dialogue: 0,0:27:59.08,0:28:02.19,Default,,0000,0000,0000,,things like checking your dependency
Dialogue: 0,0:28:01.00,0:28:04.39,Default,,0000,0000,0000,,versions
Dialogue: 0,0:28:02.19,0:28:07.15,Default,,0000,0000,0000,,they're also things are just setting up
Dialogue: 0,0:28:04.39,0:28:09.16,Default,,0000,0000,0000,,build systems and often you don't just
Dialogue: 0,0:28:07.15,0:28:11.32,Default,,0000,0000,0000,,want a local build system you want to
Dialogue: 0,0:28:09.16,0:28:13.45,Default,,0000,0000,0000,,build process that includes other types
Dialogue: 0,0:28:11.32,0:28:15.31,Default,,0000,0000,0000,,of systems or you want them to run even
Dialogue: 0,0:28:13.45,0:28:18.25,Default,,0000,0000,0000,,when your computer is not necessarily on
Dialogue: 0,0:28:15.31,0:28:20.08,Default,,0000,0000,0000,,and this is why as you start working a
Dialogue: 0,0:28:18.25,0:28:22.54,Default,,0000,0000,0000,,larger and larger project you will see
Dialogue: 0,0:28:20.08,0:28:24.58,Default,,0000,0000,0000,,people use this idea of continuous
Dialogue: 0,0:28:22.54,0:28:29.05,Default,,0000,0000,0000,,integration and continuous integration
Dialogue: 0,0:28:24.58,0:28:32.05,Default,,0000,0000,0000,,systems are essentially a cloud build
Dialogue: 0,0:28:29.05,0:28:33.61,Default,,0000,0000,0000,,system the idea is that you have your
Dialogue: 0,0:28:32.05,0:28:36.40,Default,,0000,0000,0000,,project stored on the internet somewhere
Dialogue: 0,0:28:33.61,0:28:39.46,Default,,0000,0000,0000,,and you have set it up with some kind of
Dialogue: 0,0:28:36.40,0:28:41.62,Default,,0000,0000,0000,,service that is running an ongoing thing
Dialogue: 0,0:28:39.46,0:28:44.14,Default,,0000,0000,0000,,you for your project whatever it might
Dialogue: 0,0:28:41.62,0:28:45.84,Default,,0000,0000,0000,,be and continuous integration can be all
Dialogue: 0,0:28:44.14,0:28:48.25,Default,,0000,0000,0000,,sorts of stuff it can be stuff like
Dialogue: 0,0:28:45.84,0:28:50.14,Default,,0000,0000,0000,,releasing your library to pi PI
Dialogue: 0,0:28:48.25,0:28:52.63,Default,,0000,0000,0000,,automatically whenever you push to a
Dialogue: 0,0:28:50.14,0:28:53.44,Default,,0000,0000,0000,,particular branch it could be things
Dialogue: 0,0:28:52.63,0:28:55.27,Default,,0000,0000,0000,,like
Dialogue: 0,0:28:53.44,0:28:57.72,Default,,0000,0000,0000,,run your test suite whenever someone
Dialogue: 0,0:28:55.27,0:29:00.70,Default,,0000,0000,0000,,submits a pull request or it could be
Dialogue: 0,0:28:57.72,0:29:02.86,Default,,0000,0000,0000,,check your code style every time you
Dialogue: 0,0:29:00.70,0:29:04.36,Default,,0000,0000,0000,,commit there all sorts of things you
Dialogue: 0,0:29:02.86,0:29:06.34,Default,,0000,0000,0000,,could do with continuous integration and
Dialogue: 0,0:29:04.36,0:29:08.23,Default,,0000,0000,0000,,the easiest way to think about them is
Dialogue: 0,0:29:06.34,0:29:10.93,Default,,0000,0000,0000,,that they're sort of event triggered
Dialogue: 0,0:29:08.23,0:29:12.85,Default,,0000,0000,0000,,actions so whenever a particular event
Dialogue: 0,0:29:10.93,0:29:14.74,Default,,0000,0000,0000,,happens for your a possibly for your
Dialogue: 0,0:29:12.85,0:29:17.20,Default,,0000,0000,0000,,project a particular action takes place
Dialogue: 0,0:29:14.74,0:29:20.35,Default,,0000,0000,0000,,where the action is usually some kind of
Dialogue: 0,0:29:17.20,0:29:21.52,Default,,0000,0000,0000,,script some sequence of programs they're
Dialogue: 0,0:29:20.35,0:29:27.25,Default,,0000,0000,0000,,gonna be invoked and they're gonna do
Dialogue: 0,0:29:21.52,0:29:29.74,Default,,0000,0000,0000,,something this is really an umbrella
Dialogue: 0,0:29:27.25,0:29:32.29,Default,,0000,0000,0000,,term that encapsulate a lot of different
Dialogue: 0,0:29:29.74,0:29:33.97,Default,,0000,0000,0000,,types of services so some continuous
Dialogue: 0,0:29:32.29,0:29:38.01,Default,,0000,0000,0000,,integration services are very general
Dialogue: 0,0:29:33.97,0:29:42.76,Default,,0000,0000,0000,,things like Travis CI or Azure pipelines
Dialogue: 0,0:29:38.01,0:29:45.64,Default,,0000,0000,0000,,or github actions are all very broad CI
Dialogue: 0,0:29:42.76,0:29:47.83,Default,,0000,0000,0000,,platforms they're built to let you write
Dialogue: 0,0:29:45.64,0:29:50.95,Default,,0000,0000,0000,,what you want to happen whenever any
Dialogue: 0,0:29:47.83,0:29:53.41,Default,,0000,0000,0000,,event that you define happens very broad
Dialogue: 0,0:29:50.95,0:29:56.40,Default,,0000,0000,0000,,systems there are some more specialized
Dialogue: 0,0:29:53.41,0:29:59.44,Default,,0000,0000,0000,,systems that deal with things like
Dialogue: 0,0:29:56.40,0:30:02.02,Default,,0000,0000,0000,,continuous integration coverage testing
Dialogue: 0,0:29:59.44,0:30:03.88,Default,,0000,0000,0000,,so like annotate your code and show you
Dialogue: 0,0:30:02.02,0:30:05.56,Default,,0000,0000,0000,,have no tests that test this piece of
Dialogue: 0,0:30:03.88,0:30:07.42,Default,,0000,0000,0000,,code and they're built only for that
Dialogue: 0,0:30:05.56,0:30:10.99,Default,,0000,0000,0000,,purpose or they're built only for
Dialogue: 0,0:30:07.42,0:30:13.48,Default,,0000,0000,0000,,testing browser-based libraries or
Dialogue: 0,0:30:10.99,0:30:15.49,Default,,0000,0000,0000,,something like that and so often you can
Dialogue: 0,0:30:13.48,0:30:17.11,Default,,0000,0000,0000,,find CI tools that are built for the
Dialogue: 0,0:30:15.49,0:30:18.40,Default,,0000,0000,0000,,particular project you're working on or
Dialogue: 0,0:30:17.11,0:30:20.68,Default,,0000,0000,0000,,you can use one of these broader
Dialogue: 0,0:30:18.40,0:30:22.30,Default,,0000,0000,0000,,providers and one thing that's nice is
Dialogue: 0,0:30:20.68,0:30:24.19,Default,,0000,0000,0000,,that many of them are actually free
Dialogue: 0,0:30:22.30,0:30:25.63,Default,,0000,0000,0000,,especially for open source software or
Dialogue: 0,0:30:24.19,0:30:30.16,Default,,0000,0000,0000,,if you're a student you can often get
Dialogue: 0,0:30:25.63,0:30:32.65,Default,,0000,0000,0000,,them for free as well in general the way
Dialogue: 0,0:30:30.16,0:30:35.71,Default,,0000,0000,0000,,you use the CI system is that you add a
Dialogue: 0,0:30:32.65,0:30:37.78,Default,,0000,0000,0000,,file to your repository and this file is
Dialogue: 0,0:30:35.71,0:30:39.73,Default,,0000,0000,0000,,often known as a recipe and what the
Dialogue: 0,0:30:37.78,0:30:41.98,Default,,0000,0000,0000,,recipe specifies is this sort of
Dialogue: 0,0:30:39.73,0:30:44.53,Default,,0000,0000,0000,,dependency cycle again sort of what we
Dialogue: 0,0:30:41.98,0:30:46.66,Default,,0000,0000,0000,,saw with make files it's not quite the
Dialogue: 0,0:30:44.53,0:30:49.30,Default,,0000,0000,0000,,same the events instead of being files
Dialogue: 0,0:30:46.66,0:30:51.61,Default,,0000,0000,0000,,might be something like when someone
Dialogue: 0,0:30:49.30,0:30:54.79,Default,,0000,0000,0000,,pushes a commit or when a commit
Dialogue: 0,0:30:51.61,0:30:57.12,Default,,0000,0000,0000,,contains a particular message or when
Dialogue: 0,0:30:54.79,0:31:00.79,Default,,0000,0000,0000,,someone submits a pull request or
Dialogue: 0,0:30:57.12,0:31:02.56,Default,,0000,0000,0000,,continuously write one example of a
Dialogue: 0,0:31:00.79,0:31:04.42,Default,,0000,0000,0000,,continuous integration service that's
Dialogue: 0,0:31:02.56,0:31:05.92,Default,,0000,0000,0000,,not tied to any particular change to
Dialogue: 0,0:31:04.42,0:31:06.53,Default,,0000,0000,0000,,your code is something called the
Dialogue: 0,0:31:05.92,0:31:09.20,Default,,0000,0000,0000,,dependable
Dialogue: 0,0:31:06.53,0:31:10.88,Default,,0000,0000,0000,,you can find this on github and the
Dialogue: 0,0:31:09.20,0:31:13.52,Default,,0000,0000,0000,,dependent bots is something that you
Dialogue: 0,0:31:10.88,0:31:15.71,Default,,0000,0000,0000,,hook up to your your repository and it
Dialogue: 0,0:31:13.52,0:31:17.75,Default,,0000,0000,0000,,will just scan whether there are newer
Dialogue: 0,0:31:15.71,0:31:20.42,Default,,0000,0000,0000,,versions available of your dependencies
Dialogue: 0,0:31:17.75,0:31:23.27,Default,,0000,0000,0000,,that you're not using so for example if
Dialogue: 0,0:31:20.42,0:31:24.83,Default,,0000,0000,0000,,I was depending on eight one seven and I
Dialogue: 0,0:31:23.27,0:31:27.05,Default,,0000,0000,0000,,had a lock file that locked it to eight
Dialogue: 0,0:31:24.83,0:31:29.24,Default,,0000,0000,0000,,two four and then eight three zero is
Dialogue: 0,0:31:27.05,0:31:30.92,Default,,0000,0000,0000,,released the dependable will go you
Dialogue: 0,0:31:29.24,0:31:31.94,Default,,0000,0000,0000,,should update your log file and then
Dialogue: 0,0:31:30.92,0:31:34.52,Default,,0000,0000,0000,,submit the pull request to your
Dialogue: 0,0:31:31.94,0:31:36.05,Default,,0000,0000,0000,,repository with that update this is a
Dialogue: 0,0:31:34.52,0:31:38.30,Default,,0000,0000,0000,,continuous integration service it's not
Dialogue: 0,0:31:36.05,0:31:43.10,Default,,0000,0000,0000,,tied to me changing anything but to the
Dialogue: 0,0:31:38.30,0:31:46.13,Default,,0000,0000,0000,,ecosystem at large changing often these
Dialogue: 0,0:31:43.10,0:31:48.92,Default,,0000,0000,0000,,CI systems integrate the back into your
Dialogue: 0,0:31:46.13,0:31:50.78,Default,,0000,0000,0000,,project as well so very often these CI
Dialogue: 0,0:31:48.92,0:31:57.11,Default,,0000,0000,0000,,services will provide things like little
Dialogue: 0,0:31:50.78,0:31:59.99,Default,,0000,0000,0000,,badges so let me give an example so for
Dialogue: 0,0:31:57.11,0:32:01.40,Default,,0000,0000,0000,,example here's a project I've worked on
Dialogue: 0,0:31:59.99,0:32:04.70,Default,,0000,0000,0000,,recently that has continuous integration
Dialogue: 0,0:32:01.40,0:32:09.29,Default,,0000,0000,0000,,set up so this project you'll notice
Dialogue: 0,0:32:04.70,0:32:13.61,Default,,0000,0000,0000,,it's readme if I can zoom in here with
Dialogue: 0,0:32:09.29,0:32:17.57,Default,,0000,0000,0000,,that chrome bean nope nope that's much
Dialogue: 0,0:32:13.61,0:32:19.79,Default,,0000,0000,0000,,larger than I wanted here you'll see
Dialogue: 0,0:32:17.57,0:32:22.31,Default,,0000,0000,0000,,that at the top of the the repositories
Dialogue: 0,0:32:19.79,0:32:24.59,Default,,0000,0000,0000,,page they're a bunch of these badges and
Dialogue: 0,0:32:22.31,0:32:26.03,Default,,0000,0000,0000,,they display very various types of
Dialogue: 0,0:32:24.59,0:32:27.92,Default,,0000,0000,0000,,information you'll notice that I have
Dialogue: 0,0:32:26.03,0:32:30.02,Default,,0000,0000,0000,,dependable running right so the
Dialogue: 0,0:32:27.92,0:32:31.73,Default,,0000,0000,0000,,dependencies are currently up to date it
Dialogue: 0,0:32:30.02,0:32:33.29,Default,,0000,0000,0000,,tells me about whether the test suite is
Dialogue: 0,0:32:31.73,0:32:36.14,Default,,0000,0000,0000,,currently passing on the master branch
Dialogue: 0,0:32:33.29,0:32:39.77,Default,,0000,0000,0000,,it tells me how much of the code is
Dialogue: 0,0:32:36.14,0:32:41.33,Default,,0000,0000,0000,,coverage by tests and it tells me what
Dialogue: 0,0:32:39.77,0:32:43.40,Default,,0000,0000,0000,,is the latest version of this library
Dialogue: 0,0:32:41.33,0:32:44.90,Default,,0000,0000,0000,,and what is the latest version of the
Dialogue: 0,0:32:43.40,0:32:47.69,Default,,0000,0000,0000,,documentation of the library that's
Dialogue: 0,0:32:44.90,0:32:50.03,Default,,0000,0000,0000,,available online and all of these are
Dialogue: 0,0:32:47.69,0:32:52.22,Default,,0000,0000,0000,,managed by various continues continuous
Dialogue: 0,0:32:50.03,0:32:54.41,Default,,0000,0000,0000,,integration services another example
Dialogue: 0,0:32:52.22,0:32:56.45,Default,,0000,0000,0000,,that some of you might find useful or
Dialogue: 0,0:32:54.41,0:33:00.89,Default,,0000,0000,0000,,might even be familiar with is the
Dialogue: 0,0:32:56.45,0:33:03.14,Default,,0000,0000,0000,,notion of github pages so github pages
Dialogue: 0,0:33:00.89,0:33:06.38,Default,,0000,0000,0000,,is a really nice service the github
Dialogue: 0,0:33:03.14,0:33:13.52,Default,,0000,0000,0000,,provides which lets you set up a CI
Dialogue: 0,0:33:06.38,0:33:16.85,Default,,0000,0000,0000,,action that builds your repository as a
Dialogue: 0,0:33:13.52,0:33:19.35,Default,,0000,0000,0000,,blog essentially it's it runs a static
Dialogue: 0,0:33:16.85,0:33:21.93,Default,,0000,0000,0000,,site generator called Jekyll
Dialogue: 0,0:33:19.35,0:33:24.51,Default,,0000,0000,0000,,and Jeckle just takes a bunch of
Dialogue: 0,0:33:21.93,0:33:27.78,Default,,0000,0000,0000,,markdown files and then produces a
Dialogue: 0,0:33:24.51,0:33:29.88,Default,,0000,0000,0000,,complete website and that as a part of
Dialogue: 0,0:33:27.78,0:33:31.65,Default,,0000,0000,0000,,get up pages they will also upload that
Dialogue: 0,0:33:29.88,0:33:35.13,Default,,0000,0000,0000,,to get up servers and make it available
Dialogue: 0,0:33:31.65,0:33:36.54,Default,,0000,0000,0000,,at a particular domain and this is
Dialogue: 0,0:33:35.13,0:33:39.33,Default,,0000,0000,0000,,actually how the class website works
Dialogue: 0,0:33:36.54,0:33:41.79,Default,,0000,0000,0000,,class website is not a bunch of like
Dialogue: 0,0:33:39.33,0:33:47.55,Default,,0000,0000,0000,,HTML pages that we manage instead
Dialogue: 0,0:33:41.79,0:33:49.76,Default,,0000,0000,0000,,there's a repository missing semester so
Dialogue: 0,0:33:47.55,0:33:53.55,Default,,0000,0000,0000,,if you look at the missing semester
Dialogue: 0,0:33:49.76,0:33:58.35,Default,,0000,0000,0000,,repository you will see if i zoom out a
Dialogue: 0,0:33:53.55,0:34:01.65,Default,,0000,0000,0000,,little here that this just has a bunch
Dialogue: 0,0:33:58.35,0:34:07.86,Default,,0000,0000,0000,,of markdown files right it has saket
Dialogue: 0,0:34:01.65,0:34:10.56,Default,,0000,0000,0000,,20/20 metaprogramming md so this is the
Dialogue: 0,0:34:07.86,0:34:14.19,Default,,0000,0000,0000,,if I go to raw here this is the raw
Dialogue: 0,0:34:10.56,0:34:15.81,Default,,0000,0000,0000,,markdown for today's lecture so this is
Dialogue: 0,0:34:14.19,0:34:18.57,Default,,0000,0000,0000,,the way that I write the lecture notes
Dialogue: 0,0:34:15.81,0:34:21.39,Default,,0000,0000,0000,,and then I commit that to the repository
Dialogue: 0,0:34:18.57,0:34:24.60,Default,,0000,0000,0000,,we have and I push it and whenever a
Dialogue: 0,0:34:21.39,0:34:27.57,Default,,0000,0000,0000,,push happens the github pages CI is
Dialogue: 0,0:34:24.60,0:34:32.25,Default,,0000,0000,0000,,gonna run the build script for github
Dialogue: 0,0:34:27.57,0:34:34.47,Default,,0000,0000,0000,,pages and produces the website for our
Dialogue: 0,0:34:32.25,0:34:37.59,Default,,0000,0000,0000,,class without me having to do any
Dialogue: 0,0:34:34.47,0:34:47.13,Default,,0000,0000,0000,,additional steps to make that happen and
Dialogue: 0,0:34:37.59,0:34:49.11,Default,,0000,0000,0000,,so yeah sorry good yeah so so Jekyll
Dialogue: 0,0:34:47.13,0:34:54.54,Default,,0000,0000,0000,,it's using a tool called Jekyll which is
Dialogue: 0,0:34:49.11,0:34:56.12,Default,,0000,0000,0000,,a tool that takes a directory structure
Dialogue: 0,0:34:54.54,0:34:58.83,Default,,0000,0000,0000,,that contains markdown files and
Dialogue: 0,0:34:56.12,0:35:01.71,Default,,0000,0000,0000,,produces a website it produces like HTML
Dialogue: 0,0:34:58.83,0:35:04.08,Default,,0000,0000,0000,,files and then as a part of the action
Dialogue: 0,0:35:01.71,0:35:06.27,Default,,0000,0000,0000,,it takes those files and uploads them to
Dialogue: 0,0:35:04.08,0:35:08.43,Default,,0000,0000,0000,,github servers add a particular domain
Dialogue: 0,0:35:06.27,0:35:12.09,Default,,0000,0000,0000,,and usually that's the domain under like
Dialogue: 0,0:35:08.43,0:35:14.67,Default,,0000,0000,0000,,github I oh that they control and then I
Dialogue: 0,0:35:12.09,0:35:23.85,Default,,0000,0000,0000,,have set missing semester to point to
Dialogue: 0,0:35:14.67,0:35:26.94,Default,,0000,0000,0000,,the github domain I want to give you one
Dialogue: 0,0:35:23.85,0:35:29.01,Default,,0000,0000,0000,,aside on testing because it's something
Dialogue: 0,0:35:26.94,0:35:30.96,Default,,0000,0000,0000,,that many of you may be familiar with
Dialogue: 0,0:35:29.01,0:35:32.67,Default,,0000,0000,0000,,from before right you have a rough idea
Dialogue: 0,0:35:30.96,0:35:34.68,Default,,0000,0000,0000,,of what testing is you
Dialogue: 0,0:35:32.67,0:35:37.44,Default,,0000,0000,0000,,run the test before you've seen a test
Dialogue: 0,0:35:34.68,0:35:38.88,Default,,0000,0000,0000,,fail you know like the basics of it or
Dialogue: 0,0:35:37.44,0:35:43.17,Default,,0000,0000,0000,,maybe you've never seen a test fail in
Dialogue: 0,0:35:38.88,0:35:45.06,Default,,0000,0000,0000,,case congratulations but as you as you
Dialogue: 0,0:35:43.17,0:35:47.91,Default,,0000,0000,0000,,get to more advanced projects though
Dialogue: 0,0:35:45.06,0:35:50.31,Default,,0000,0000,0000,,you'll find that people have a lot of
Dialogue: 0,0:35:47.91,0:35:53.25,Default,,0000,0000,0000,,terminology around testing and testing
Dialogue: 0,0:35:50.31,0:35:55.11,Default,,0000,0000,0000,,is a pretty like deep subject that you
Dialogue: 0,0:35:53.25,0:35:56.91,Default,,0000,0000,0000,,could spend many many hours trying to
Dialogue: 0,0:35:55.11,0:35:57.84,Default,,0000,0000,0000,,understand the ins and outs of and I'm
Dialogue: 0,0:35:56.91,0:35:59.67,Default,,0000,0000,0000,,not going to go through it in
Dialogue: 0,0:35:57.84,0:36:01.50,Default,,0000,0000,0000,,excruciating detail but there are a
Dialogue: 0,0:35:59.67,0:36:04.08,Default,,0000,0000,0000,,couple of words that I think it's useful
Dialogue: 0,0:36:01.50,0:36:06.48,Default,,0000,0000,0000,,to know what mean and the first of these
Dialogue: 0,0:36:04.08,0:36:09.15,Default,,0000,0000,0000,,is a test suite so a test suite is a
Dialogue: 0,0:36:06.48,0:36:11.91,Default,,0000,0000,0000,,very straightforward name for all of the
Dialogue: 0,0:36:09.15,0:36:13.95,Default,,0000,0000,0000,,tests in a program it's really just a
Dialogue: 0,0:36:11.91,0:36:16.73,Default,,0000,0000,0000,,suite of tests it's a large collection
Dialogue: 0,0:36:13.95,0:36:20.01,Default,,0000,0000,0000,,of tests that usually are run as a unit
Dialogue: 0,0:36:16.73,0:36:22.98,Default,,0000,0000,0000,,and there are different types of tests
Dialogue: 0,0:36:20.01,0:36:24.72,Default,,0000,0000,0000,,that often make up a test suite the
Dialogue: 0,0:36:22.98,0:36:27.93,Default,,0000,0000,0000,,first of these is what's known as a unit
Dialogue: 0,0:36:24.72,0:36:31.17,Default,,0000,0000,0000,,test a unit test is a often usually
Dialogue: 0,0:36:27.93,0:36:34.74,Default,,0000,0000,0000,,fairly small test of self-contained
Dialogue: 0,0:36:31.17,0:36:37.08,Default,,0000,0000,0000,,tests the tests a single feature what
Dialogue: 0,0:36:34.74,0:36:39.21,Default,,0000,0000,0000,,exactly a feature might mean is a little
Dialogue: 0,0:36:37.08,0:36:41.04,Default,,0000,0000,0000,,bit up to the project but the idea is
Dialogue: 0,0:36:39.21,0:36:44.85,Default,,0000,0000,0000,,that should be sort of a micro test that
Dialogue: 0,0:36:41.04,0:36:46.29,Default,,0000,0000,0000,,only tests a very particular thing then
Dialogue: 0,0:36:44.85,0:36:48.90,Default,,0000,0000,0000,,you have the larger tests that are known
Dialogue: 0,0:36:46.29,0:36:50.55,Default,,0000,0000,0000,,as integration tests integration tests
Dialogue: 0,0:36:48.90,0:36:54.36,Default,,0000,0000,0000,,try to test the interaction between
Dialogue: 0,0:36:50.55,0:36:57.36,Default,,0000,0000,0000,,different subsystems of a program so
Dialogue: 0,0:36:54.36,0:37:00.27,Default,,0000,0000,0000,,this might be something like an example
Dialogue: 0,0:36:57.36,0:37:03.39,Default,,0000,0000,0000,,of a unit test might be if you're
Dialogue: 0,0:37:00.27,0:37:06.36,Default,,0000,0000,0000,,writing an HTML parser to the unit test
Dialogue: 0,0:37:03.39,0:37:09.93,Default,,0000,0000,0000,,might be test that it can parse an HTML
Dialogue: 0,0:37:06.36,0:37:13.68,Default,,0000,0000,0000,,tag an integration test might be here's
Dialogue: 0,0:37:09.93,0:37:14.64,Default,,0000,0000,0000,,an HTML document parse it right so that
Dialogue: 0,0:37:13.68,0:37:15.75,Default,,0000,0000,0000,,is going to be the interview the
Dialogue: 0,0:37:14.64,0:37:19.68,Default,,0000,0000,0000,,integration of multiple of the
Dialogue: 0,0:37:15.75,0:37:22.59,Default,,0000,0000,0000,,subsystems of the parser you also have a
Dialogue: 0,0:37:19.68,0:37:25.17,Default,,0000,0000,0000,,notion of regression tests regression
Dialogue: 0,0:37:22.59,0:37:28.05,Default,,0000,0000,0000,,tests are tests that test things that
Dialogue: 0,0:37:25.17,0:37:31.08,Default,,0000,0000,0000,,were broken in the past so imagine that
Dialogue: 0,0:37:28.05,0:37:33.36,Default,,0000,0000,0000,,someone submits some kind of issue to
Dialogue: 0,0:37:31.08,0:37:38.82,Default,,0000,0000,0000,,you and says your library breaks if I
Dialogue: 0,0:37:33.36,0:37:40.71,Default,,0000,0000,0000,,give it a marquee tag and that makes you
Dialogue: 0,0:37:38.82,0:37:43.04,Default,,0000,0000,0000,,sad so you want to fix it so you fix
Dialogue: 0,0:37:40.71,0:37:45.87,Default,,0000,0000,0000,,your parser to now support marquee tags
Dialogue: 0,0:37:43.04,0:37:46.59,Default,,0000,0000,0000,,but then you want to add a test to your
Dialogue: 0,0:37:45.87,0:37:48.48,Default,,0000,0000,0000,,test suite
Dialogue: 0,0:37:46.59,0:37:51.21,Default,,0000,0000,0000,,the checks that you can parse marquee
Dialogue: 0,0:37:48.48,0:37:53.25,Default,,0000,0000,0000,,tags the reason for this is so that in
Dialogue: 0,0:37:51.21,0:37:56.52,Default,,0000,0000,0000,,the future you don't accidentally
Dialogue: 0,0:37:53.25,0:37:58.29,Default,,0000,0000,0000,,reintroduce that bug. So that is what
Dialogue: 0,0:37:56.52,0:37:59.67,Default,,0000,0000,0000,,a regression tests are for and over time
Dialogue: 0,0:37:58.29,0:38:01.32,Default,,0000,0000,0000,,your project is gonna build up more and
Dialogue: 0,0:37:59.67,0:38:02.64,Default,,0000,0000,0000,,more of these, and they're nice because
Dialogue: 0,0:38:01.32,0:38:07.32,Default,,0000,0000,0000,,they prevent your project from
Dialogue: 0,0:38:02.64,0:38:10.08,Default,,0000,0000,0000,,regressing to earlier bugs. The last one
Dialogue: 0,0:38:07.32,0:38:15.81,Default,,0000,0000,0000,,I want to mention is a concept called
Dialogue: 0,0:38:10.08,0:38:18.00,Default,,0000,0000,0000,,mocking. So mocking is the idea of being
Dialogue: 0,0:38:15.81,0:38:20.61,Default,,0000,0000,0000,,able to replace parts of your system
Dialogue: 0,0:38:18.00,0:38:26.19,Default,,0000,0000,0000,,with a sort of dummy version of itself
Dialogue: 0,0:38:20.61,0:38:29.01,Default,,0000,0000,0000,,that behaves in a way that you control. A
Dialogue: 0,0:38:26.19,0:38:33.06,Default,,0000,0000,0000,,common example of this is you're writing
Dialogue: 0,0:38:29.01,0:38:36.15,Default,,0000,0000,0000,,something that does, oh I don't know, file
Dialogue: 0,0:38:33.06,0:38:37.17,Default,,0000,0000,0000,,copying over SSH. Right? This is a tool
Dialogue: 0,0:38:36.15,0:38:40.11,Default,,0000,0000,0000,,that you've written that does file
Dialogue: 0,0:38:37.17,0:38:42.06,Default,,0000,0000,0000,,copying over SSH there are many things
Dialogue: 0,0:38:40.11,0:38:43.11,Default,,0000,0000,0000,,you might want to mock here. For example,
Dialogue: 0,0:38:42.06,0:38:44.70,Default,,0000,0000,0000,,when running your test suite you
Dialogue: 0,0:38:43.11,0:38:47.04,Default,,0000,0000,0000,,probably don't actually care that
Dialogue: 0,0:38:44.70,0:38:49.38,Default,,0000,0000,0000,,there's a network there. Right? You don't
Dialogue: 0,0:38:47.04,0:38:51.06,Default,,0000,0000,0000,,need to have to like set up TCP ports
Dialogue: 0,0:38:49.38,0:38:53.61,Default,,0000,0000,0000,,and stuff, so instead you're gonna mock
Dialogue: 0,0:38:51.06,0:38:55.68,Default,,0000,0000,0000,,the network. The way this usually works
Dialogue: 0,0:38:53.61,0:38:57.66,Default,,0000,0000,0000,,is that, somewhere in your library, you
Dialogue: 0,0:38:55.68,0:38:59.67,Default,,0000,0000,0000,,have something that like opens a
Dialogue: 0,0:38:57.66,0:39:01.59,Default,,0000,0000,0000,,connection, or reads from the connection,
Dialogue: 0,0:38:59.67,0:39:03.33,Default,,0000,0000,0000,,or writes to the connection, and you're
Dialogue: 0,0:39:01.59,0:39:05.70,Default,,0000,0000,0000,,gonna overwrite those functions
Dialogue: 0,0:39:03.33,0:39:07.53,Default,,0000,0000,0000,,internally in your library with
Dialogue: 0,0:39:05.70,0:39:09.69,Default,,0000,0000,0000,,functions that you've written just for
Dialogue: 0,0:39:07.53,0:39:11.91,Default,,0000,0000,0000,,the purposes of testing, where the read
Dialogue: 0,0:39:09.69,0:39:13.59,Default,,0000,0000,0000,,function just like returns the data, and
Dialogue: 0,0:39:11.91,0:39:15.23,Default,,0000,0000,0000,,the write function just drops the data
Dialogue: 0,0:39:13.59,0:39:17.64,Default,,0000,0000,0000,,on the floor, or something like that.
Dialogue: 0,0:39:15.23,0:39:20.01,Default,,0000,0000,0000,,Similarly, you can write a mocking
Dialogue: 0,0:39:17.64,0:39:21.18,Default,,0000,0000,0000,,function for the SSH functionality. You
Dialogue: 0,0:39:20.01,0:39:22.47,Default,,0000,0000,0000,,could write something that does not
Dialogue: 0,0:39:21.18,0:39:24.78,Default,,0000,0000,0000,,actually do encryption, it doesn't talk
Dialogue: 0,0:39:22.47,0:39:26.55,Default,,0000,0000,0000,,to the network: it just like takes bytes
Dialogue: 0,0:39:24.78,0:39:28.56,Default,,0000,0000,0000,,in here and just magically they pop out
Dialogue: 0,0:39:26.55,0:39:30.39,Default,,0000,0000,0000,,the other side, and you can ignore
Dialogue: 0,0:39:28.56,0:39:32.22,Default,,0000,0000,0000,,everything that's between, because for
Dialogue: 0,0:39:30.39,0:39:34.29,Default,,0000,0000,0000,,the purpose of copying a file, if you
Dialogue: 0,0:39:32.22,0:39:36.78,Default,,0000,0000,0000,,just wanted to test that functionality,
Dialogue: 0,0:39:34.29,0:39:40.74,Default,,0000,0000,0000,,the stuff below doesn't matter for that
Dialogue: 0,0:39:36.78,0:39:43.02,Default,,0000,0000,0000,,test, and you might mock it away. Usually,
Dialogue: 0,0:39:40.74,0:39:44.40,Default,,0000,0000,0000,,in any given language, there are tools
Dialogue: 0,0:39:43.02,0:39:49.59,Default,,0000,0000,0000,,that let you build these kind of mocking
Dialogue: 0,0:39:44.40,0:39:51.48,Default,,0000,0000,0000,,abstractions pretty easily. That is the
Dialogue: 0,0:39:49.59,0:39:53.82,Default,,0000,0000,0000,,end of what I wanted to talk about
Dialogue: 0,0:39:51.48,0:39:56.31,Default,,0000,0000,0000,,metaprogramming, but this is a very, very
Dialogue: 0,0:39:53.82,0:39:58.95,Default,,0000,0000,0000,,broad subject. Things like continuous
Dialogue: 0,0:39:56.31,0:39:59.74,Default,,0000,0000,0000,,integration, build systems, there are so
Dialogue: 0,0:39:58.95,0:40:01.96,Default,,0000,0000,0000,,many out there
Dialogue: 0,0:39:59.74,0:40:03.94,Default,,0000,0000,0000,,that can let you do so many interesting
Dialogue: 0,0:40:01.96,0:40:05.47,Default,,0000,0000,0000,,things with your projects, so I highly
Dialogue: 0,0:40:03.94,0:40:11.23,Default,,0000,0000,0000,,recommend that you start looking into it
Dialogue: 0,0:40:05.47,0:40:12.97,Default,,0000,0000,0000,,a little. The exercises are sort of all
Dialogue: 0,0:40:11.23,0:40:16.03,Default,,0000,0000,0000,,over the place, and I mean that in a good
Dialogue: 0,0:40:12.97,0:40:17.97,Default,,0000,0000,0000,,way. They're intended to try to just show
Dialogue: 0,0:40:16.03,0:40:20.77,Default,,0000,0000,0000,,you the kind of possibilities that exist
Dialogue: 0,0:40:17.97,0:40:22.99,Default,,0000,0000,0000,,for build working with these kind of
Dialogue: 0,0:40:20.77,0:40:25.72,Default,,0000,0000,0000,,processes so for example the last
Dialogue: 0,0:40:22.99,0:40:28.05,Default,,0000,0000,0000,,exercise has you write one of these
Dialogue: 0,0:40:25.72,0:40:31.30,Default,,0000,0000,0000,,continuous integration actions yourself
Dialogue: 0,0:40:28.05,0:40:33.85,Default,,0000,0000,0000,,where it you decide what the event be
Dialogue: 0,0:40:31.30,0:40:35.98,Default,,0000,0000,0000,,and you decide what the action be but
Dialogue: 0,0:40:33.85,0:40:37.24,Default,,0000,0000,0000,,try to actually build one and this can
Dialogue: 0,0:40:35.98,0:40:39.76,Default,,0000,0000,0000,,be something that you might find useful
Dialogue: 0,0:40:37.24,0:40:42.97,Default,,0000,0000,0000,,in your project the example I given the
Dialogue: 0,0:40:39.76,0:40:45.64,Default,,0000,0000,0000,,exercises is try to build an action that
Dialogue: 0,0:40:42.97,0:40:46.87,Default,,0000,0000,0000,,runs like right good or pro Slynt one of
Dialogue: 0,0:40:45.64,0:40:49.69,Default,,0000,0000,0000,,the linters result for the english
Dialogue: 0,0:40:46.87,0:40:52.33,Default,,0000,0000,0000,,language on your repository and if you
Dialogue: 0,0:40:49.69,0:40:56.02,Default,,0000,0000,0000,,do like we could enable that for the
Dialogue: 0,0:40:52.33,0:40:57.82,Default,,0000,0000,0000,,class repository so that our lecture
Dialogue: 0,0:40:56.02,0:41:00.34,Default,,0000,0000,0000,,notes are actually well written right
Dialogue: 0,0:40:57.82,0:41:01.45,Default,,0000,0000,0000,,and this is one other thing that's nice
Dialogue: 0,0:41:00.34,0:41:04.42,Default,,0000,0000,0000,,about this kind of continuous
Dialogue: 0,0:41:01.45,0:41:06.19,Default,,0000,0000,0000,,integration testing is that you can
Dialogue: 0,0:41:04.42,0:41:08.56,Default,,0000,0000,0000,,collaborate between projects if you
Dialogue: 0,0:41:06.19,0:41:09.91,Default,,0000,0000,0000,,write one I can use it in my project and
Dialogue: 0,0:41:08.56,0:41:11.68,Default,,0000,0000,0000,,there's a really handy feature where you
Dialogue: 0,0:41:09.91,0:41:15.46,Default,,0000,0000,0000,,can build this ecosystem of improving
Dialogue: 0,0:41:11.68,0:41:32.59,Default,,0000,0000,0000,,everything any questions about any of
Dialogue: 0,0:41:15.46,0:41:35.83,Default,,0000,0000,0000,,the stuff we record today yeah so the
Dialogue: 0,0:41:32.59,0:41:38.44,Default,,0000,0000,0000,,question is why do we have both make and
Dialogue: 0,0:41:35.83,0:41:41.23,Default,,0000,0000,0000,,see make what do they do and is there a
Dialogue: 0,0:41:38.44,0:41:44.77,Default,,0000,0000,0000,,reason for them to talk together so so
Dialogue: 0,0:41:41.23,0:41:46.84,Default,,0000,0000,0000,,see make I don't actually know what the
Dialogue: 0,0:41:44.77,0:41:49.63,Default,,0000,0000,0000,,tagline for C make is anymore but it's
Dialogue: 0,0:41:46.84,0:41:54.51,Default,,0000,0000,0000,,sort of like a better make for C as the
Dialogue: 0,0:41:49.63,0:41:57.28,Default,,0000,0000,0000,,name implies C make generally
Dialogue: 0,0:41:54.51,0:41:58.66,Default,,0000,0000,0000,,understands the layout of C projects a
Dialogue: 0,0:41:57.28,0:42:01.60,Default,,0000,0000,0000,,little bit better than make Falls do
Dialogue: 0,0:41:58.66,0:42:03.55,Default,,0000,0000,0000,,they're sort of built to try to parse
Dialogue: 0,0:42:01.60,0:42:04.87,Default,,0000,0000,0000,,out what the structure of your
Dialogue: 0,0:42:03.55,0:42:06.64,Default,,0000,0000,0000,,dependencies are what the rules from
Dialogue: 0,0:42:04.87,0:42:08.20,Default,,0000,0000,0000,,going to one to the other is it also
Dialogue: 0,0:42:06.64,0:42:11.47,Default,,0000,0000,0000,,integrates a little bit nicer with
Dialogue: 0,0:42:08.20,0:42:12.83,Default,,0000,0000,0000,,things like system libraries so C may
Dialogue: 0,0:42:11.47,0:42:14.57,Default,,0000,0000,0000,,can do things like detect
Dialogue: 0,0:42:12.83,0:42:16.16,Default,,0000,0000,0000,,given libraries available on your
Dialogue: 0,0:42:14.57,0:42:17.93,Default,,0000,0000,0000,,computer or if it's available at
Dialogue: 0,0:42:16.16,0:42:20.33,Default,,0000,0000,0000,,multiple different paths it tries to
Dialogue: 0,0:42:17.93,0:42:22.25,Default,,0000,0000,0000,,find which of those paths it's present
Dialogue: 0,0:42:20.33,0:42:24.23,Default,,0000,0000,0000,,on on this system and then link it
Dialogue: 0,0:42:22.25,0:42:27.71,Default,,0000,0000,0000,,appropriately so see make is a little
Dialogue: 0,0:42:24.23,0:42:29.78,Default,,0000,0000,0000,,bit smarter than make is make will only
Dialogue: 0,0:42:27.71,0:42:31.52,Default,,0000,0000,0000,,do whatever you put in the make file not
Dialogue: 0,0:42:29.78,0:42:33.56,Default,,0000,0000,0000,,entirely true there are things called
Dialogue: 0,0:42:31.52,0:42:35.93,Default,,0000,0000,0000,,implicit rules that are like built-in
Dialogue: 0,0:42:33.56,0:42:37.100,Default,,0000,0000,0000,,rules in make but they're pretty dumb
Dialogue: 0,0:42:35.93,0:42:40.76,Default,,0000,0000,0000,,whereas emic tries to be able to be a
Dialogue: 0,0:42:37.100,0:42:43.06,Default,,0000,0000,0000,,larger build system that is opinionated
Dialogue: 0,0:42:40.76,0:42:46.22,Default,,0000,0000,0000,,by default to work for C projects
Dialogue: 0,0:42:43.06,0:42:49.76,Default,,0000,0000,0000,,similarly there's a tool called maven so
Dialogue: 0,0:42:46.22,0:42:52.04,Default,,0000,0000,0000,,maven and ant which is another project
Dialogue: 0,0:42:49.76,0:42:54.77,Default,,0000,0000,0000,,they are both built for Java projects
Dialogue: 0,0:42:52.04,0:42:56.48,Default,,0000,0000,0000,,they understand how Java code interacts
Dialogue: 0,0:42:54.77,0:42:59.08,Default,,0000,0000,0000,,with one another how you structure Java
Dialogue: 0,0:42:56.48,0:43:02.09,Default,,0000,0000,0000,,programs and they're built for that task
Dialogue: 0,0:42:59.08,0:43:05.18,Default,,0000,0000,0000,,very often at least when I use make I
Dialogue: 0,0:43:02.09,0:43:07.55,Default,,0000,0000,0000,,use make sort of at the top and then
Dialogue: 0,0:43:05.18,0:43:09.26,Default,,0000,0000,0000,,make my call other tools that build
Dialogue: 0,0:43:07.55,0:43:11.87,Default,,0000,0000,0000,,whatever subsystem they know how to
Dialogue: 0,0:43:09.26,0:43:14.72,Default,,0000,0000,0000,,build right like my make file might call
Dialogue: 0,0:43:11.87,0:43:16.28,Default,,0000,0000,0000,,cargo to build a rust program and then
Dialogue: 0,0:43:14.72,0:43:18.68,Default,,0000,0000,0000,,call see make to build some like see
Dialogue: 0,0:43:16.28,0:43:21.41,Default,,0000,0000,0000,,dependency of that but then at the top
Dialogue: 0,0:43:18.68,0:43:23.24,Default,,0000,0000,0000,,like I'm gonna do some stuff at the end
Dialogue: 0,0:43:21.41,0:43:24.98,Default,,0000,0000,0000,,after the programs have built and that
Dialogue: 0,0:43:23.24,0:43:27.20,Default,,0000,0000,0000,,might just be like run a benchmark which
Dialogue: 0,0:43:24.98,0:43:28.91,Default,,0000,0000,0000,,is in the rust code and then like plot
Dialogue: 0,0:43:27.20,0:43:31.16,Default,,0000,0000,0000,,it using the C code or something like
Dialogue: 0,0:43:28.91,0:43:33.76,Default,,0000,0000,0000,,that right so for me make you sort of
Dialogue: 0,0:43:31.16,0:43:36.17,Default,,0000,0000,0000,,the glue at the top that I might write
Dialogue: 0,0:43:33.76,0:43:40.82,Default,,0000,0000,0000,,usually if your make file gets very
Dialogue: 0,0:43:36.17,0:43:42.38,Default,,0000,0000,0000,,large there's a better tool would you'll
Dialogue: 0,0:43:40.82,0:43:45.05,Default,,0000,0000,0000,,find it like big companies for example
Dialogue: 0,0:43:42.38,0:43:47.81,Default,,0000,0000,0000,,is they often have one build system that
Dialogue: 0,0:43:45.05,0:43:49.40,Default,,0000,0000,0000,,manages all of their software so if you
Dialogue: 0,0:43:47.81,0:43:51.98,Default,,0000,0000,0000,,look at Google for example they have
Dialogue: 0,0:43:49.40,0:43:54.20,Default,,0000,0000,0000,,this open source system called basil and
Dialogue: 0,0:43:51.98,0:43:57.38,Default,,0000,0000,0000,,I don't think Google literally uses
Dialogue: 0,0:43:54.20,0:43:59.63,Default,,0000,0000,0000,,basil inside of Google but it's sort of
Dialogue: 0,0:43:57.38,0:44:02.18,Default,,0000,0000,0000,,based on what they use internally and it
Dialogue: 0,0:43:59.63,0:44:04.63,Default,,0000,0000,0000,,really just its intended to manage the
Dialogue: 0,0:44:02.18,0:44:09.44,Default,,0000,0000,0000,,entire build of everything Google has
Dialogue: 0,0:44:04.63,0:44:11.51,Default,,0000,0000,0000,,and basil in particular is built to be I
Dialogue: 0,0:44:09.44,0:44:13.67,Default,,0000,0000,0000,,think they call it like a polyglot build
Dialogue: 0,0:44:11.51,0:44:15.77,Default,,0000,0000,0000,,framework so the idea is that it works
Dialogue: 0,0:44:13.67,0:44:17.66,Default,,0000,0000,0000,,for many different languages there's
Dialogue: 0,0:44:15.77,0:44:19.70,Default,,0000,0000,0000,,like an implement there's a module for
Dialogue: 0,0:44:17.66,0:44:21.26,Default,,0000,0000,0000,,basil for this language and that
Dialogue: 0,0:44:19.70,0:44:23.54,Default,,0000,0000,0000,,language in that language but they all
Dialogue: 0,0:44:21.26,0:44:26.09,Default,,0000,0000,0000,,integrate with the same basil framework
Dialogue: 0,0:44:23.54,0:44:27.77,Default,,0000,0000,0000,,which then knows how to integrate
Dialogue: 0,0:44:26.09,0:44:33.22,Default,,0000,0000,0000,,dependencies between different libraries
Dialogue: 0,0:44:27.77,0:44:33.22,Default,,0000,0000,0000,,and different languages get a question
Dialogue: 0,0:44:39.34,0:44:42.11,Default,,0000,0000,0000,,sure
Dialogue: 0,0:44:40.79,0:44:48.01,Default,,0000,0000,0000,,so when you say expressions you mean the
Dialogue: 0,0:44:42.11,0:44:48.01,Default,,0000,0000,0000,,things in this file or yeah so these are
Dialogue: 0,0:44:48.70,0:44:56.86,Default,,0000,0000,0000,,so make files are their own language
Dialogue: 0,0:44:52.54,0:45:00.20,Default,,0000,0000,0000,,they are it's a pretty weird language
Dialogue: 0,0:44:56.86,0:45:02.75,Default,,0000,0000,0000,,like it has a lot of weird exceptions in
Dialogue: 0,0:45:00.20,0:45:04.40,Default,,0000,0000,0000,,many ways it's weird just like bash is
Dialogue: 0,0:45:02.75,0:45:06.17,Default,,0000,0000,0000,,weird but in different ways which is
Dialogue: 0,0:45:04.40,0:45:08.45,Default,,0000,0000,0000,,even worse like when you're writing a
Dialogue: 0,0:45:06.17,0:45:09.89,Default,,0000,0000,0000,,make file you sort of you can sort of
Dialogue: 0,0:45:08.45,0:45:11.06,Default,,0000,0000,0000,,think like you're writing bash but
Dialogue: 0,0:45:09.89,0:45:13.79,Default,,0000,0000,0000,,you're not because it's broken in
Dialogue: 0,0:45:11.06,0:45:16.73,Default,,0000,0000,0000,,different ways but but it is its own
Dialogue: 0,0:45:13.79,0:45:20.00,Default,,0000,0000,0000,,language and the way that make files are
Dialogue: 0,0:45:16.73,0:45:21.29,Default,,0000,0000,0000,,generally structured is that you have a
Dialogue: 0,0:45:20.00,0:45:25.46,Default,,0000,0000,0000,,sequence of I think they call them
Dialogue: 0,0:45:21.29,0:45:28.94,Default,,0000,0000,0000,,directives so every like the this thing
Dialogue: 0,0:45:25.46,0:45:31.88,Default,,0000,0000,0000,,oops this thing is a directive and this
Dialogue: 0,0:45:28.94,0:45:34.13,Default,,0000,0000,0000,,is a directive and every directive has a
Dialogue: 0,0:45:31.88,0:45:35.87,Default,,0000,0000,0000,,colon somewhere and everything to the
Dialogue: 0,0:45:34.13,0:45:38.17,Default,,0000,0000,0000,,left of the colon is a target and
Dialogue: 0,0:45:35.87,0:45:42.86,Default,,0000,0000,0000,,everything to the right of the colon is
Dialogue: 0,0:45:38.17,0:45:45.56,Default,,0000,0000,0000,,right of the colon is a dependency and
Dialogue: 0,0:45:42.86,0:45:49.13,Default,,0000,0000,0000,,then all of the lines below that line
Dialogue: 0,0:45:45.56,0:45:51.86,Default,,0000,0000,0000,,are the sequence of operations known as
Dialogue: 0,0:45:49.13,0:45:53.09,Default,,0000,0000,0000,,the rules for once you have the
Dialogue: 0,0:45:51.86,0:45:55.40,Default,,0000,0000,0000,,dependencies how do you build these
Dialogue: 0,0:45:53.09,0:45:58.64,Default,,0000,0000,0000,,targets notice that make is very
Dialogue: 0,0:45:55.40,0:46:01.34,Default,,0000,0000,0000,,particular that you must use a tab to
Dialogue: 0,0:45:58.64,0:46:04.01,Default,,0000,0000,0000,,indent the rules if you do not make will
Dialogue: 0,0:46:01.34,0:46:06.25,Default,,0000,0000,0000,,not work if they must be tabs they
Dialogue: 0,0:46:04.01,0:46:08.27,Default,,0000,0000,0000,,cannot be four eight spaces must be tabs
Dialogue: 0,0:46:06.25,0:46:10.49,Default,,0000,0000,0000,,and like you can have multiple
Dialogue: 0,0:46:08.27,0:46:12.98,Default,,0000,0000,0000,,operations here I like I can do echo
Dialogue: 0,0:46:10.49,0:46:16.07,Default,,0000,0000,0000,,hello or whatever and then they would
Dialogue: 0,0:46:12.98,0:46:18.23,Default,,0000,0000,0000,,first run this and then run this there's
Dialogue: 0,0:46:16.07,0:46:20.33,Default,,0000,0000,0000,,a there's an exercise for today's
Dialogue: 0,0:46:18.23,0:46:22.70,Default,,0000,0000,0000,,lecture that has you try to extend this
Dialogue: 0,0:46:20.33,0:46:24.08,Default,,0000,0000,0000,,make file with a couple of other targets
Dialogue: 0,0:46:22.70,0:46:26.23,Default,,0000,0000,0000,,that you might find interesting that
Dialogue: 0,0:46:24.08,0:46:30.02,Default,,0000,0000,0000,,goes into a little bit more detail
Dialogue: 0,0:46:26.23,0:46:33.38,Default,,0000,0000,0000,,there's also some ability to execute
Dialogue: 0,0:46:30.02,0:46:35.51,Default,,0000,0000,0000,,external commands to like determine what
Dialogue: 0,0:46:33.38,0:46:37.58,Default,,0000,0000,0000,,the dependencies might be if your
Dialogue: 0,0:46:35.51,0:46:39.68,Default,,0000,0000,0000,,dependencies are not like a static list
Dialogue: 0,0:46:37.58,0:46:41.66,Default,,0000,0000,0000,,of files but it's a little limited
Dialogue: 0,0:46:39.68,0:46:43.88,Default,,0000,0000,0000,,usually once you've started needing that
Dialogue: 0,0:46:41.66,0:46:59.54,Default,,0000,0000,0000,,sort of stuff you might want to move to
Dialogue: 0,0:46:43.88,0:47:06.41,Default,,0000,0000,0000,,a more advanced build system yeah so the
Dialogue: 0,0:46:59.54,0:47:09.35,Default,,0000,0000,0000,,question is what happens if I have let's
Dialogue: 0,0:47:06.41,0:47:14.00,Default,,0000,0000,0000,,say that I have library a and library B
Dialogue: 0,0:47:09.35,0:47:18.65,Default,,0000,0000,0000,,and they both depend on library see but
Dialogue: 0,0:47:14.00,0:47:25.40,Default,,0000,0000,0000,,library a depends on like 4.0.1 and
Dialogue: 0,0:47:18.65,0:47:27.23,Default,,0000,0000,0000,,library B depends on 3 dot 4 dot 7 so
Dialogue: 0,0:47:25.40,0:47:29.21,Default,,0000,0000,0000,,they both depend on C and so ideally
Dialogue: 0,0:47:27.23,0:47:31.85,Default,,0000,0000,0000,,we'd like to reuse see but they depend
Dialogue: 0,0:47:29.21,0:47:34.76,Default,,0000,0000,0000,,on different major versions of C what do
Dialogue: 0,0:47:31.85,0:47:37.61,Default,,0000,0000,0000,,we do well what happens in this case
Dialogue: 0,0:47:34.76,0:47:39.17,Default,,0000,0000,0000,,depends entirely on the system that
Dialogue: 0,0:47:37.61,0:47:42.11,Default,,0000,0000,0000,,you're using the language that you're
Dialogue: 0,0:47:39.17,0:47:44.21,Default,,0000,0000,0000,,using in some cases the tool would just
Dialogue: 0,0:47:42.11,0:47:45.74,Default,,0000,0000,0000,,be like well I'll just pick for which
Dialogue: 0,0:47:44.21,0:47:48.89,Default,,0000,0000,0000,,sort of implies that they're not really
Dialogue: 0,0:47:45.74,0:47:52.18,Default,,0000,0000,0000,,using semantic versioning in some cases
Dialogue: 0,0:47:48.89,0:47:54.65,Default,,0000,0000,0000,,the tool will say this is not possible
Dialogue: 0,0:47:52.18,0:47:57.92,Default,,0000,0000,0000,,like if you do this it's an error and
Dialogue: 0,0:47:54.65,0:48:00.17,Default,,0000,0000,0000,,the tool will tell you you either need
Dialogue: 0,0:47:57.92,0:48:02.84,Default,,0000,0000,0000,,to upgrade be like have B use a newer
Dialogue: 0,0:48:00.17,0:48:04.66,Default,,0000,0000,0000,,version of C or you need to downgrade a
Dialogue: 0,0:48:02.84,0:48:08.21,Default,,0000,0000,0000,,you do not get to do this and
Dialogue: 0,0:48:04.66,0:48:11.75,Default,,0000,0000,0000,,compilation will fail some tools are
Dialogue: 0,0:48:08.21,0:48:15.74,Default,,0000,0000,0000,,gonna build two versions of C and then
Dialogue: 0,0:48:11.75,0:48:18.80,Default,,0000,0000,0000,,like when it builds a it will use the
Dialogue: 0,0:48:15.74,0:48:20.27,Default,,0000,0000,0000,,major four version of C and when it
Dialogue: 0,0:48:18.80,0:48:23.21,Default,,0000,0000,0000,,builds B will use the major three
Dialogue: 0,0:48:20.27,0:48:25.58,Default,,0000,0000,0000,,version of C one thing you end up with
Dialogue: 0,0:48:23.21,0:48:28.07,Default,,0000,0000,0000,,is really weird conditions here were
Dialogue: 0,0:48:25.58,0:48:29.60,Default,,0000,0000,0000,,like if C has dependencies then now you
Dialogue: 0,0:48:28.07,0:48:32.63,Default,,0000,0000,0000,,have to build all of C's dependencies
Dialogue: 0,0:48:29.60,0:48:35.27,Default,,0000,0000,0000,,twice to 1 for 3 and 1 for 4 and maybe
Dialogue: 0,0:48:32.63,0:48:36.89,Default,,0000,0000,0000,,they share and maybe they don't you can
Dialogue: 0,0:48:35.27,0:48:43.24,Default,,0000,0000,0000,,end up in particularly weird situations
Dialogue: 0,0:48:36.89,0:48:43.24,Default,,0000,0000,0000,,if imagine that the library see like
Dialogue: 0,0:48:44.59,0:48:48.04,Default,,0000,0000,0000,,imagine that
Dialogue: 0,0:48:48.77,0:48:55.59,Default,,0000,0000,0000,,library see like rights to a file like
Dialogue: 0,0:48:52.89,0:48:58.29,Default,,0000,0000,0000,,rights to some like file on disk some
Dialogue: 0,0:48:55.59,0:49:01.47,Default,,0000,0000,0000,,cache stuff if you run your application
Dialogue: 0,0:48:58.29,0:49:04.38,Default,,0000,0000,0000,,now and like a does something to call
Dialogue: 0,0:49:01.47,0:49:07.29,Default,,0000,0000,0000,,like C dot save and B to something like
Dialogue: 0,0:49:04.38,0:49:08.55,Default,,0000,0000,0000,,C adult load then suddenly your your
Dialogue: 0,0:49:07.29,0:49:10.32,Default,,0000,0000,0000,,application of the bottom is not going
Dialogue: 0,0:49:08.55,0:49:11.46,Default,,0000,0000,0000,,to work because the format is different
Dialogue: 0,0:49:10.32,0:49:13.08,Default,,0000,0000,0000,,right
Dialogue: 0,0:49:11.46,0:49:15.57,Default,,0000,0000,0000,,so these situations are often very
Dialogue: 0,0:49:13.08,0:49:17.70,Default,,0000,0000,0000,,problematic and and most tools that
Dialogue: 0,0:49:15.57,0:49:19.50,Default,,0000,0000,0000,,support semantic versioning will reject
Dialogue: 0,0:49:17.70,0:49:21.57,Default,,0000,0000,0000,,this kind of configuration for exactly
Dialogue: 0,0:49:19.50,0:49:27.09,Default,,0000,0000,0000,,that reason but it's so easy to shoot
Dialogue: 0,0:49:21.57,0:49:30.18,Default,,0000,0000,0000,,yourself in the foot all right we will
Dialogue: 0,0:49:27.09,0:49:31.56,Default,,0000,0000,0000,,see you again tomorrow for security keep
Dialogue: 0,0:49:30.18,0:49:34.08,Default,,0000,0000,0000,,in mind again if you haven't done the
Dialogue: 0,0:49:31.56,0:49:36.24,Default,,0000,0000,0000,,survey the question I care the most
Dialogue: 0,0:49:34.08,0:49:38.22,Default,,0000,0000,0000,,about in the survey is what you would
Dialogue: 0,0:49:36.24,0:49:40.47,Default,,0000,0000,0000,,like us to cover in the last two
Dialogue: 0,0:49:38.22,0:49:42.87,Default,,0000,0000,0000,,lectures so the last two lectures are
Dialogue: 0,0:49:40.47,0:49:45.45,Default,,0000,0000,0000,,for you to choose what you want us to
Dialogue: 0,0:49:42.87,0:49:47.25,Default,,0000,0000,0000,,talk about and to give any questions you
Dialogue: 0,0:49:45.45,0:49:50.19,Default,,0000,0000,0000,,want us to answer so please like add
Dialogue: 0,0:49:47.25,0:49:52.40,Default,,0000,0000,0000,,that if you can and that's it see you
Dialogue: 0,0:49:50.19,0:49:52.40,Default,,0000,0000,0000,,tomorrow