Tag Archives : Parsing Expression Grammar


Morning Coffee 166

Yes, I realize it’s been a while. I tried in vain to catch up with my blog reading after my Hawaii vacation and finally just gave up and hit “mark all as read”.

Dynamic Languages

  • There’s a new version of the DLR hosting spec available (doc, pdf). The DLR implementation is still in motion, so there are some inconsistencies between the spec and the code, but the spec should give you the high level overview you need if you want to host DLR languages inside your app.
  • Oleg Tkachenko recently joined the dynamic languages team. He’s the creator of the Interactive IronRuby Web Shell, an IronRuby version of Try Ruby. Of course, it’s not as cool as using SL2to execute the code directly in the browser. Michael Foord has his Python in the Browser and my teammates John and Jimmy demoed a Silverlight version of Try Ruby @ TechEd.
  • Jim Deville, also of the dynamic languages team, recently started blogging.
  • I have a new boss, Dave Remy. He doesn’t have a blog – yet – but you can follow him on Twitter as daveremy. When Twitter is actually working that is.
  • There’s a new homepage/wiki for IronRuby though I’m not sure why there’s a picture of Matz wearing a Python shirt on the home page.
  • My teammate Jimmy Schementi provides some “continued hope” for a better (heck, I’ll take current) ASP.NET and ASP.NET MVC story for DLR languages.
  • Via Michael Foord, sounds like IronClad is making good progress. V0.4 can run the bz2 module “in its entirity” (maybe run a spellcheck on your site, guys?) and now apparently, it’s now able to load numpy.core. Very exciting!

Other Stuff

  • Pat Helland, who has blogged even less than me for the past few months, has a post up about controller and doers in the IT department. After 18 months in MSIT, put me in the doer camp, please.
  • The F# team has pushed out a spec for v1.9.4 of the language. Don Syme says it’s not official, but it’s a huge improvement over the old informal spec
  • Speaking of F#, my friend Matthew Podwysocki recently published FsTest, a testing DSL for F#. I wrote about F# unit testing as part of my PEG parsing series, and I really like the direction Matthew has taken this project. You can pull it down from CodePlex.
  • When I did my PEG talk @ Lang.NET, Gilad Bracha mentioned I should check out oMeta. It looks really cool, though with the job change I haven’t had the time to play with it. Now I discover that Jeff Moser is working on a version for CLR called oMeta# that I’ve got to spend some time with. And in the comments to that post, I discovered pyMeta from Allen Short, though it apparently doesn’t work on IronPython (must investigate why).
  • James Kovacs introduces psake, a PowerShell based build automation tool which uses a rake-inspired internal DSL syntax similar to one I blogged last year. I’d love to see this take off, but given MSBuild’s tool integration, I wonder if that’s feasible.
  • I upgraded my home wireless network almost exactly a year ago. I’ve been happy with the range and coverage, but not so happy with the Buffalo Tech firmware. The built-in DHCP server is pretty flaky. So I upgraded to the open-source Tomato firmware. Upgrade was smooth, though I did need to reset my cable modem. But even that was smooth – Comcast has an automated service for that now,

Morning Coffee 149


Morning Coffee 144

  • I finished Mass Effect last night. I definitely need to play thru that one again, though I’ll probably wait until the new Bring Down the Sky DLC ships next month.
  • Caps won again last night, improving to 20-10-4 since changing coaches at Thanksgiving. They’re now at 57 points, taking the lead in the SE division with a full game on Carolina, Atlanta and Florida. Still a ways to go – 27 games left in the regular season – and things are far from “sewn up” but we’re a damn sight better off than we were in November.
  • Speaking of a horserace, looks like Clinton and Obama are in one after Super Tuesday. Their estimated delegate counts are basically tied. On the other side of the aisle, McCain opened up what is probably insurmountable lead – even though he has the right-wing media stars and Christian leaders against him. Money quote of the day:

“The real story of the night, when you look at their rallies and their turn-out numbers, is that the Dems have two strong candidates either of whom could lead a united party to victory. Forget the gaseous platitudes: in Dem terms, their choice on Super Duper Tuesday was deciding which candidate was Super Duper and which was merely Super. Over on the GOP side, it was a choice between Weak & Divisive or Weaker & Unacceptable. Doesn’t bode well for November.”
- Mark Steyn, National Review 
(via Carpetbagger Report, lest you think I regularly read National Review)

  • Charlie Calvert is starting a new series on the future of C#. First up: Dynamic Lookup. Probably most interesting is the news that the DLR “will be the infrastructure on which the C# team implements dynamic lookup”. Does this mean C# will target the DLR? Sure sounds like it. I think it’s a good addition, but I’m not a fan of the proposed syntax. (via Bitter Coder)
  • Brian McNamara saw me present @ LangNET and sent me a link to his blog. He’s building up a monadic parser combinator library in C# 3.0. This is basically the same concept that FParsec implements, though C#’s syntax is much less attractive than F#’s for this kind of code. However, Brian does a very good job explaining why monadic parser combinators are useful and making the idea accessible to the C# programmer (i.e. you don’t have to learn F# or Haskell to understand what he’s talking about). He also points to Luke Hoban’s C# 3.0 monadic parser implementation.

Morning Coffee 143

  • I’ve been sick for three days, hence the lack of posting around here.
  • As a Redskins fan, it’s hard to root for any other NFC East team. On the other hand, it sure was easy to root against the Patriots. Congrats to the Giants on their Super Bowl victory. Favorite headline: 18 and uh-oh!
  • Sounds like there’s cause for optimism regarding the writer’s strike. But is it already too late? Will the 9% drop in viewers ever come back? Personally, I think the studios have hastened their own irrelevance.
  • With last night’s win, the Caps are one game above .500. In and of itself, that’s nothing to be proud of – Coach Boudreau remarked when we reached .500 that the Caps had “officially reached mediocrity”. However, the Caps are the only team in the SE conference that’s above .500. If hockey used baseball standings, Carolina, Atlanta and Florida would each be 1/2 game back of the Caps. It’s going to be a fight to the finish.
  • In fairly big managed Ruby news, Wayne Kelly has decided to contribute to the IronRuby effort, effectively walking away from the Ruby.NET which helped get off the ground. One the one hand, obviously this is great for IronRuby. On the other hand, I liked the idea of multiple managed implementations of Ruby, so here’s hoping Ruby.NET doesn’t fade away.
  • Speaking of the DLR, I know I mentioned Martin Maly’s blog in my Lang.NET Morning Coffee Post, but I didn’t actually get to read his posts on targeting the DLR until I unexpectedly had several days off sick. If you are at all interested in writing your own language for the .NET platform: Go. Read. Now. You should also check out Tomas Restrepo’s blog, he has also started writing about targeting the DLR.
  • Larry O’Brien’s blog is currently offline, but he commented that he doubted my ToyScript F# parser would be more than 600 lines of code. Currently, the parser is clocking in at 287 lines of code plus about 50 more for the AST. It’s not done yet – see earlier statement about being sick – but I’m fixing bugs not writing additional code at this point. To be completely accurate, that’s 287 lines of FParsec code. It’s taken me a little bit to learn FParsec, but so far I’m pretty happy with it.
  • Scott Hanselman points to the new MS Deploy project, a tool for managing content and configuration on web servers. I’ve never understood why this wasn’t a standard part of IIS. It seems every hosting company I’ve used has rolled their own web-based management tool like DotNetPanel.
  • Oh yeah, Vista SP1 and Windows Server 2008 shipped Monday. Congrats!
  • I fired up Inside Xbox the other day, and there was a page about the new Disney Channel show “Phineas and Ferb“. Of course, with two kids under five, anything new on the Disney Channel is notable in my house. What made this blog-worthy is the fact that it’s directed and written by Dan Povenmire, who I knew from my USC days. I used to go see his band Keep Left and groan loudly at the bad puns in their song “PSA”. Dan, if you found this searching for yourself online: Awesome work, my kids love the show!

Morning Coffee 141 – Lang.NET ’08 Edition

header I was hoping to blog my thoughts on Lang.NET as the event went along. Obviously, that didn’t happen, though I was pretty good about dumping links into my del.icio.us feed. The talks were all recorded, and should be up on the website in a week or two. Rather than provide a detailed summary of everything that happened, here are my highlights:

  • The coolest thing about conferences like this is what John Rose called “N3″ aka “Nerd-to-Nerd Networking”. It was great to meet in person, drink with and geek out with folks who’s blogs I read like Tomas Petricek, Wesner Moise and Larry O’Brien. Plus, I got to meet a bunch of other cool folks like Gilad Bracha, Stefan Wenig and Wez Furlong. That’s worth the price of admission (which was admittedly nothing) right there.
  • Coolest MSFT talk: Martin Maly “Targeting DLR”. I was wholly unaware that the DLR includes an entire compiler back end. Martin summarized the idea of DLR trees on his blog, but the short version is “you parse the language, DLR generates the code”. That’s pretty cool, and should dramatically lower the bar for language development. Of course, I want to write my parser in F#, so I’m going to port the DLR ToyScript sample to F#.
  • Runner-up, Coolest MSFT talk: Erik Meijer “Democratizing the Cloud with Volta”. Erik is a great speaker and he really set the tone of his session with the comment “Division by zero is the goal, not an error”. He was referring to an idea from The Change Function that user’s measure of success is a function of perceived crisis divided by perceived pain of adoption. Erik wants to drive that adoption pain to zero. It’s a laudable goal, but I remain unconvinced on Volta.
  • Coolest Non-MSFT talk: Gilad Bracha “Newspeak”. Newspeak is a new language from one of the co-authors of Java. It’s heavily smalltalk influenced, and runs on Squeak. He showed developing PEGs in Newspeak, and they were very compact and easy to read, easier even than F#. He calls them Executable grammar, and you can read his research paper or review his slides on the topic. Unfortunately, Newspeak isn’t generally available at this time.
  • Runner-up, Coolest Non-MSFT talk: Miguel de Icaza “Moonlight and Mono”. The talk was kinda all-over-the-place, but It’s great to see how far Mono has come. Second Life just started beta testing a Mono-based script runner for their LSL language (apparently, Mono breaks many LSL scripts because it runs them so fast). He also showed off Unity, a 3D game development tool, also running on Mono.
  • Resolver One is a product that bridges the gap between spreadsheets and applications, entirely written in IronPython (around 30,000 lines of app code and 110,000 lines of test code, all in IPy). Creating a spread-sheet based app development environment is one of those ideas that seems obvious in retrospect, at least to me. If you do any kind of complicated spreadsheet based analysis, you should check out their product.
  • If you’re a PowerShell user, you should check out PowerShell+. It’s a free console environment designed for PowerShell and a damn sight better than CMD.exe. If you’re not a PowerShell user, what the heck is wrong with you?
  • Other projects to take a deeper look at: C# Mixins and Cobra Language.
  • I thought my talk went pretty well. It’s was a 15 minute version of my Practical Parsing in F# series. Several folks were surprised I’ve been coding F# for less than a year.