Parrot is a virtual machine designed to efficiently compile and execute bytecode for dynamic languages. Parrot currently hosts a variety of language implementations in various stages of completion, including Tcl, Javascript, Ruby, Lua, Scheme, PHP, Python, Perl 6, APL, and a .NET bytecode translator. Parrot is not about parrots, though we are rather fond of them for obvious reasons.

SOD: Symbolic Opcode Description

Well, GSoC is starting to wind down. I can't believe it's almost over. It feels like the "pencils down" date just jumped up out of nowhere. I had a lot more planned for HBDB but there are many flaws in Parrot's design that make even some of the most basic debugging tasks very difficult which I'll explain in a moment.

GSoC: LALR Parsing: A revised schedule

I'm far behind on my project, unfortunately, and, upon dukeleto's urging, I've written up a new timeline that I think I will be able to finish before Summer of Code ends.

First, I'll summarize what I have done:

  • An object representation for grammars
  • An object representation for deterministic push-down automata(DPDAs)
  • Generation of DPDAs for LR(0) grammars
  • The beginnings of an interpreter for DPDAs

And what I haven't done:

  • Actually producing a parse tree while parsing

GSoC 11: Breaking Radio Silence

*tap, tap, tap* Is this thing on? It is? Drat, I had hoped it wasn't and I'd have something to blame for the long silence.

Due to the issues I'm about to describe, my old schedule is a little off. The important schedule note is that the official "pencils down" date is August 15th, aka next week. Current plan is to power through as much as I can in the next few days. At this point, I doubt that my branch will be merged into master before the end of GSoC, but I do intend to keep working on it.

The core of my problem is in this line from my last blog post:

strings, encodings, and NCI

With the recent addition of the as_string method to UnManagedStruct and Ptr PMCs (see my last post) and the get_pointer vtable in ByteBuffer now is easier to pass and get strings from NCI (parrot Native Calll Interface).

To pass a string to a NCI 'p' parameter you just need to create a ByteBuffer and set the string to it, maybe after trans_encoding it, and add the zero-termination required in most usages by pushing a 0 value. ByteBuffer takes care of memory management.

IMCC Wars: Episode IV - A New Hope

A long time ago in a galaxy far, far away...

It is a period of binary war. Rebel hackers, striking from a hidden base in New Jersey have won their first victory against the evil IMCC Empire.

We need a better way to get strings from NCI

The last refactor of the NCI subsystem got rid of the 't' type used to pass C strings. This gives us more flexibility but doesn't solve all problems.

Take for example Mysql: we can specify the character set used for the connection with the database, and sometimes we can't use the current locale. We may want to read a table that contains unicode characters out of the range compatible with latin-1 without loses, while using latin-1 locale.

HBDB Closed for Construction, Please Use Detour

This past week was admittedly dull. I've reached a bit a road block and this time it's blocking the way forwards, backwards, left, and right.

Parrot-GMP: Hiatus while I move across town

My coding has been put on hold this week as I move across town and deal with some shenanigans from the landlord. The good news is that my wife and I should be able to move into our new house on Tuesday or Wednesday - the bad news is that I am currently internet-less until then. I've been working on updating the tutorial which doesn't require any internet access, just time. By this time next week I hope to complete the tutorial, have some more examples, and begin trying to get some examples in NQP or even on Rakudo.

Parrot 3.6 Release Quotation Contest Is Over

The release quotation contest is over. We received four submissions, each of which was correct. In order of receipt, they were from:

  1. Ville Koskinen
  2. Lucas Buchala
  3. Daniel S.
  4. Javier M. Mora

Each of the four submissions appears to have met the do-not-use-the-Internet condition for researching the answer. In fact, each of the four appear to have gotten the answer the old-fashioned way:

They remembered it!

GSoC: LALR Parsing: Midterms over!

We're halfway through the summer, now. I have not made nearly as much progress as I had previously hoped. Partly this is due to the difficulty of the problem, and partl\
y it is because I have not spent enough time on it. I think I'm currently at a point where I'm only a few mostly simple transformations away from producing a Determinis\
tic Push-Down Automaton which will be capable of parsing a LR(0) grammar. Whether implementing those last few mostly simple transformations will show this belief to be \
correct or not, I won't know until I do so.

Here are my next few goals:

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