text
stringlengths
0
1.17k
[1215.38 --> 1222.42] the sooner you can start focusing on the work you love focus on your work not your paperwork again go to
[1222.42 --> 1230.18] uh go to this url getfreshbooks.com and enter the change log in the how did you hear about us section
[1230.18 --> 1239.22] and you'll get access to that 60 day free trial from fresh books do it now do you think that uh
[1239.22 --> 1244.46] the lack of standardization right now has prevented anyone from considering building a vm for dart other
[1244.46 --> 1253.12] than google um we're still early in the process i would say um but the you cannot make a standard
[1253.12 --> 1258.98] out of something that's moving uh fast so it's important that you have a basic design of the language
[1258.98 --> 1266.28] and it's fairly stable before you standardize it so you need to be at a certain uh stage before you
[1266.28 --> 1270.36] can start standardizing i think we are there now we haven't changed the language very much since we
[1270.36 --> 1277.02] came out with one o in november uh so this is the right time to do it and uh we expect that the
[1277.02 --> 1283.68] the current spec is will be ratified in in the ecma tc 52 here uh this summer
[1283.68 --> 1289.24] that's pretty quick actually i feel like that just a few months to to have the spec ratified
[1289.24 --> 1299.58] well we started the process um uh late last year so okay it's half a year so yeah so it's funny when
[1299.58 --> 1303.84] we talked about i i felt like i had heard about dart much longer you said the project's only about three
[1303.84 --> 1312.80] years old yeah a good three years yeah so when you say yeah i mean just i i just remember hearing
[1312.80 --> 1316.96] about dart and i guess maybe i've made so many life changes in the last couple years that it seems
[1316.96 --> 1322.14] like it's been a lot longer but but that's a pretty quick process in general to to start the language and
[1322.14 --> 1327.34] get to a point now where we're talking about you know like like when you started dart three years ago
[1327.34 --> 1332.28] was it something that it was an experiment or or did you did you kind of envision it being this
[1332.28 --> 1341.84] here only three years in the future um well i hoped it would be at this point uh so but when you
[1341.84 --> 1349.60] started it was not an experiment uh um like five years ago um i did an experiment with casper that
[1349.60 --> 1356.50] where we spent one quarter do a dart like dart like language we did a vm and an implementation just
[1356.50 --> 1362.74] to see how it would work on the web um and that looked pretty good so uh three years ago we got
[1362.74 --> 1369.26] the the go ahead uh to do it but it was not an experiment we really wanted to change how you did
[1369.26 --> 1375.94] uh web applications or you could there was an alternative to do web applications so uh i think
[1375.94 --> 1381.10] we are on good track three years is not long for a new programming language and we're getting good
[1381.10 --> 1386.48] traction the the interesting part is that people that actually have tried uh dart and developed
[1386.48 --> 1393.18] some real code with it they are fairly happy and that's what makes me proud yeah i mean i would
[1393.18 --> 1397.46] encourage anyone to just go to the website and and you can tell very quickly that this is not
[1397.46 --> 1402.38] it's very different from javascript in a lot of senses but it's very easy to pick up and you can
[1402.38 --> 1406.32] just kind of you can tell that that there's a lot of emphasis put in like you know if you're a web
[1406.32 --> 1410.44] developer if you've built things for the web right now it's not a huge hurdle to be able to write
[1410.44 --> 1416.80] dart and i think that's a major win uh for you guys for sure and uh just to to talk about the
[1416.80 --> 1423.68] seriousness of the project we are working we really hard to have a very clear semantics that's documented
[1423.68 --> 1428.48] with a language specification and making sure the implementations we have are conformant so
[1428.48 --> 1436.54] um that's what we spend a lot of time on and also making sure that when we generate a javascript
[1436.54 --> 1442.76] from dart we validate the resulting code it runs in the various modern browsers like internet explorer
[1442.76 --> 1452.28] firefox safari and obron so i want to move on a little bit to the language itself and some of the
[1452.28 --> 1455.66] design and the thought behind the language do you do you have anything else you want to say about
[1455.66 --> 1457.86] just the motivation and the theory behind dart
[1457.86 --> 1466.80] i'm just super happy being able to write in dart so i think it's really cool that i get to come to
[1466.80 --> 1471.98] work and work on something that actually makes me happier to build for the web so that i feel like
[1471.98 --> 1477.72] that's a win yeah for sure so let's talk a little bit about the language itself um can you kind of give
[1477.72 --> 1483.86] me some i don't know like obviously there this is hard to summarize in a few you know sentences because
[1483.86 --> 1487.86] i'm sure a lot of thought went behind this but but can you give me some some of the insight into
[1487.86 --> 1491.50] like the thought behind the language and and what the process looked like to figure out you know the
[1491.50 --> 1499.10] syntax of the language and all that well first of all we have to um to say that the only way to get
[1499.10 --> 1504.64] a successful language is to to include curly braces so that was the first thing oh and semicolons
[1504.64 --> 1512.30] and semicolons yes of course of course um and then secondly we uh we knew from the beginning that
[1512.30 --> 1518.30] it had to be translated to javascript and that uh uh sort of was a challenge because some of the
[1518.30 --> 1522.86] language feature we wanted to have into the language we could not put in because they would not translate
[1522.86 --> 1528.86] to efficient javascript so the design process was uh sort of very iterative in in coming up with a
[1528.86 --> 1534.22] feature that matched the language and then implement and see how it would look in in javascript one thing
[1534.22 --> 1541.10] uh or a feature we didn't put in we wanted to have but we could not make efficient on top of javascript
[1541.10 --> 1547.18] was non-local returns as you probably know from small talk it's a way to bail out from a recursive
[1547.18 --> 1552.30] algorithm very quickly but in javascript you could only implement that by throwing exception
[1552.30 --> 1557.66] and that was really slow on most implementations yeah yeah one thing that i found really fascinating
[1557.66 --> 1563.18] when i talked to the co-founders and some of the other vm uh developers for dart is the difference in
[1563.18 --> 1570.86] how how vm design impacted the language design so maybe lars like when you you helped build v8 and you
[1570.86 --> 1575.98] you took the javascript language which is very flexible uh and but you but you ultimately made
[1575.98 --> 1582.06] it very fast how did that experience help us design the dart language so that the implementations can be
[1582.06 --> 1590.62] fast well javascript is very flexible uh if you try to access a property that's not there you return
[1590.94 --> 1596.78] an undefined if you if you set a property that's not there you will expand the object with a new
[1596.78 --> 1604.94] property and so in order to make a v8 fast we had to design for a sweet spot kind of application
[1605.90 --> 1611.58] and the problem with that is that if you from the side create a new library and you poke at a few
[1611.58 --> 1617.10] objects suddenly the application would be slow so one of the design goals of dart was also to make sure
[1617.10 --> 1623.18] that we had an execution model that would be robust when it came to performance right so you can actually
[1623.18 --> 1628.46] trust that if you had a performance library it will continue to be robust no matter how you used it
[1629.90 --> 1636.46] so one of the impacts of that is dart has classes and the dart program is declared and then when the
[1637.18 --> 1641.98] virtual machine you know scans it and then parses it and then compiles it that's the structure of the
[1641.98 --> 1647.18] program and you can know that that is the structure so the vm can more quickly more easily and more
[1647.18 --> 1653.42] efficiently optimize that program we basically borrowed the the the optic model from small talk
[1654.70 --> 1661.02] so a very simple optic model where in a class you define the the fields you want to have for the
[1661.02 --> 1669.34] instances and but you cannot expand it at one time so fields have to be declared and the same way if you
[1669.34 --> 1678.30] have a non-global array and you access a fear an element outside the range you get an exception instead of
[1678.30 --> 1684.94] expanding the array so it's more rigid than than small talk in some sense on the other hand you also
[1684.94 --> 1691.18] you get notified if you do something wrong like in javascript if you do if you if you have a spelling error
[1691.18 --> 1697.66] what happens is the program continues to run but it doesn't behave the right way in dart you'll be notified
[1697.66 --> 1704.38] you try to access something that's not there so we talked a little bit about how flexible javascript
[1704.38 --> 1709.98] is and that's a kind of a double-edged sword right like it's it's neat and it's nice because it allows
[1709.98 --> 1715.34] me to do a lot but it also makes it very easy for like developers to make mistakes and in a lot of ways
[1715.34 --> 1720.70] because well for a few reasons i would imagine right the first is obviously that uh in order to compile
[1720.70 --> 1726.06] dart down to javascript like it's it's a lot easier when dart is more restrictive than javascript to be able
[1726.06 --> 1731.02] to compile to javascript and the other way is it's a lot harder it seems like to make mistakes in dart
[1731.02 --> 1735.34] in the classical way that that you can make mistakes in javascript can is it was that was that part of
[1735.34 --> 1742.30] the thought process behind some of the restrictions in dart uh clearly because uh if we want to support
[1742.30 --> 1748.54] programming in the lot right it's very important for a programmer that he can write a piece of code and be
[1748.54 --> 1754.94] fairly certain that it will work against the other libraries in the project so certainly having having a
[1754.94 --> 1761.98] tool chain that will check that the way you use the system is valid is important for big programs so
[1761.98 --> 1769.58] that was part of the design criteria and also in javascript not only properties for normal
[1771.02 --> 1777.10] fields can be added but you can also change the functionality as you go along at one time so for
[1777.10 --> 1782.38] instance if you want to swap two functions in the library of javascript you can do that without
[1783.18 --> 1788.46] getting notified but the program doesn't behave the right way in dart we have decided that the
[1789.34 --> 1793.50] libraries are declared and class are declared that means that when you first stop running
[1793.50 --> 1798.70] they will stay the same functional from the beginning of the program execution to the end and that also
[1798.70 --> 1807.42] means that you'll not get a problem with conflicts in javascript you can have monkey patching and if two
[1807.42 --> 1813.58] libraries that are monkey patching a core object you can get into a sort of interesting behavior
[1815.82 --> 1821.42] so uh one thing i want to bring up just kind of as another little aside here you've you've mentioned
[1821.42 --> 1825.18] what the first thing you mentioned was that uh obviously it had to have curly braces because you
[1825.18 --> 1829.98] know it's impossible to have a successful language without them and you've talked a lot about the influence
[1829.98 --> 1835.34] small talk the small talk had on dart uh one of my co-workers said he thinks it's reasonable