LOLCODE

LOLCODE is an esoteric programming language inspired by the language expressed in examples of the LOLCAT Internet meme. The language was created in 2007 by Benjamin Baer, researcher at the Computing Department of Lancaster University.

The language is not clearly defined in terms of operator priorities and correct syntax, but several functioning interpreters and compilers already exist. The language has been proven Turing-complete by the implementation of a Brainfuck compiler.

Language structure and examples

LOLCODE is written in heavily compressed (shortened) English Internet slang, and a person who understands this slang can often understand a LOLCODE program without prior experience. Here follows a Hello world program and a simple program to output a file to a monitor. Highly accessible, similar code was printed in the Houston Chronicle.

Example 1:

HAI
CAN HAS STDIO?
VISIBLE "HAI WORLD!"
KTHXBYE 

Code	Comment
HAI	In all LOLCODE programs, HAI (an internet slang misspelling of "hi") introduces the program.
CAN HAS [FILE]?	In many programming languages, one of the first statements will be a library inclusion for common functions such as input and output. Typically this is included by a call such as #include <stdio.h> [stdio standing for standard input/output library]. This command is a tongue in cheek corruption of that, asking if a file is obtainable, obtaining it if possible, and raising an exception if not. It is there primarily for authenticity — in fact, it is ignored in current implementations of LOLCODE.
VISIBLE [MESSAGE]	prints a message to the screen.
KTHXBYE	HAI introduces the program, so KTHXBYE (meaning "Okay — thanks — bye!") terminates it.

Example 2:

HAI
CAN HAS STDIO?
PLZ OPEN FILE "LOLCATS.TXT"?
    AWSUM THX
        VISIBLE FILE
    O NOES
        INVISIBLE "ERROR!"
KTHXBYE 

In this example, commands to open a file (PLZ OPEN FILE "NAME"? — "Please try to open a file?"), and error handling (AWSUM THX — "Awesome, thanks!", and O NOES — "Oh no!") are introduced.

Other commands include I HAS A variable for declaring variables, LOL variable R value ("laughter [at] variable [is/are/being] value") for assigning them, sending error messages to the front end via INVISIBLE instead of VISIBLE, and BTW ("by the way") to denote a comment, making the parser ignore the rest of the line. Loops are created with IM IN YR label (from an internet meme "I'm in your ___"), and ended with KTHX ("okay-thanks!"). Loops lack counters or conditions, and thus do not cease inherently. They must be manually broken with the GTFO (deprecated in favor of ENUF – "enough" in Leetspeak) command. Loops can also be ended with the conditional IZ command:

Example 3:

HAI
CAN HAS STDIO?
I HAS A VAR
IM IN YR LOOP
   UP VAR!!1
   IZ VAR BIGGER THAN 10? KTHX
   VISIBLE VAR
IM OUTTA YR LOOP
KTHXBYE  

This simple program displays the numbers 1–10 and terminates (as of specification 1.0). The same program as of specification 1.2 is (assuming VAR starts at 0):

HAI
CAN HAS STDIO?
IM IN YR LOOP UPPIN YR VAR TIL BOTHSAEM VAR AN 10
    VISIBLE SUM OF VAR AN 1
IM OUTTA YR LOOP
KTHXBYE

Implementations

There is a .NET compiler for LOLCODE written by Nick Johnson, and featured in Microsoft developer training seminars, TechEd 2007 Conference (Australia).

PL/LOLCODE, a project headed by Josh Tolley, makes LOLCODE available as a server-side programming language inside PostgreSQL.

Microsoft Dynamic Language Runtime has an implementation of LOLCODE for testing purposes.

External links

• LOLCODE Official website
• LOLPython
• The new fame: Internet celebrity, CNN article