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About

Layo is a LOLCODE interpreter written in Ruby. It tries to conform to the LOLCODE 1.2 specification and supports everything described there.

Usage

Through Rubygems:

gem install layo
layo program.lol

If you don't want to install the gem, you can download sources, extract somewhere and run from the project's root:

bin/layo program.lol

Layo treats source files as UTF-8 encoded, if your file contains non-ascii characters, be sure to encode it as UTF-8.

Without arguments Layo works in interactive mode, i.e. it executes statements read from a standard input. A sample session:

[galymzhan@g8host layo]$ bin/layo
Layo version 1.1.0
Press Control-C to exit
 > VISIBLE "HAI WORLD!"
HAI WORLD!
 > I HAS A animal ITZ "cat"
 > BOTH SAEM animal AN "cat", O RLY?
YA RLY, VISIBLE "I HAV A CAT"
NO WAI, VISIBLE "J00 SUX"
OIC
I HAV A CAT
 > ^CExiting

Oh, and there are tests too. In order to run them, you have to install mocha: gem install mocha. Then go to the project's root and execute rake test.

Requirements

  • Ruby >= 1.9.2
  • Mocha for development

LOLCODE examples

Classical hello world:

HAI 1.2
VISIBLE "Hello world!"
KTHXBYE

For more examples see examples and spec/source directories.

Grammar

Layo uses the following grammar to parse programs:

Program = "HAI 1.2" , Newline , Block , "KTHXBYE" ;
Block = { Statement } ;
Newline = ? Newline character (\r, \n, \r\n) or comma ? ;
Identifier = Letter , { Letter | Digit | "_" } ;
Letter = ? Capital or lowercase latin letter ? ;
Digit = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" ;
Type = "NOOB" | "TROOF" | "NUMBR" | "NUMBAR" | "YARN" ;

(* List of statements *)
Statement = ( AssignmentStatement | BreakStatement | CastStatement |
  ConditionStatement | DeclarationStatement | ExpressionStatement |
  FunctionStatement | InputStatement | LoopStatement |
  PrintStatement | ReturnStatement | SwitchStatement ) , Newline ;
AssignmentStatement = Identifier , "R" , Expression ;
BreakStatement = "GTFO" ;
CastStatement = Identifier , "IS NOW A" , Type ;
ConditionStatement = "O RLY?" , Newline , "YA RLY" , Newline , Block ,
  { "MEBBE" , Expression , Newline , Block } , (* else if branches *)
  [ "NO WAI" , Newline , Block ] , (* else branch *)
  "OIC" ;
DeclarationStatement = "I HAS A" , Identifier ,
  [ "ITZ" , Expression ] ; (* initialization expression *)
ExpressionStatement = Expression ;
FunctionStatement = "HOW DUZ I" , Identifier ,
  [ "YR" , Identifier , { "AN_YR" , Identifier } ] , (* argument list *)
  Newline , Block , "IF U SAY SO" ;
InputStatement = "GIMMEH" , Identifier ;
LoopStatement = "IM IN YR" , Identifier ,
  (* loop operation *)
  [ ( "UPPIN" | "NERFIN" | Identifier ) , "YR" , Identifier ] ,
  (* loop condition *)
  [ "TIL" | "WILE" , Expression ] ,
  Block , "IM OUTTA YR" , Identifier ;
PrintStatement = "VISIBLE" , Expression , { Expression } , [ "!" ] ;
ReturnStatement = "FOUND YR" , Expression ;
SwitchStatement = "WTF?" , Newline , SwitchCase , { SwitchCase } ,
  [ "OMGWTF" , Newline , Block ] , (* default case *)
  "OIC" ;
SwitchCase = "OMG" , ConstantExpression , Newline , Block ;

(* List of expressions *)
Expression = BinaryExpression | CastExpression | ConstantExpression |
  IdentifierExpression | NaryExpression | UnaryExpression ;
BinaryExpression = ( "SUM OF" | "DIFF OF" | "PRODUKT OF" | "QUOSHUNT OF" |
  "MOD OF" | "BIGGR OF" | "SMALLR OF" | "BOTH OF" | "EITHER OF" | "WON OF" |
  "BOTH SAEM" | "DIFFRINT" ) , Expression , Operand ;
Operand = [ "AN" ] , Expression ;
CastExpression = "MAEK" , Expression , "A" , Type ;
ConstantExpression = String | Number | "WIN" | "FAIL" ;
IdentifierExpression = Identifier ;
NaryExpression = ( "ALL OF" | "ANY OF" | "SMOOSH" ) ,
  Expression , Operand , { Operand } ;
UnaryExpression = "NOT" , Expression ;