HAI
BTW This is a BrainFuck interpreter written in LOLCode
BTW It accepts as input a BF program, followed by a "!", followed by any input to the BF program.
BTW Since BrainFuck is turing-complete, this proves that LOLCode is too
I HAS A INSTRUCTIONS BTW Array for BF instructions
I HAS A IPTR BTW Pointer to first empty element in INSTRUCTIONS
LOL IPTR R 0
I HAS A LOOPZ BTW Array of loop start/end addresses
I HAS A LOOPSTACKZ BTW Loop stack for building the above two
I HAS A LSPTR BTW Pointer to first empty element of LOOPSTACKZ
LOL LSPTR R 0
BTW Read in BF instructions, terminated with "!"
IM IN YR CODE
GIMMEH LETTAR IPTR IN MAH INSTRUCTIONS
IZ IPTR IN MAH INSTRUCTIONS LIEK "["?
LOL LSPTR IN MAH LOOPSTACKZ R IPTR
UPZ LSPTR!!
KTHX
IZ IPTR IN MAH INSTRUCTIONS LIEK "]"?
I HAS A STARTPTR
NERFZ LSPTR!!
LOL STARTPTR R LSPTR IN MAH LOOPSTACKZ
LOL STARTPTR IN MAH LOOPZ R IPTR
LOL IPTR IN MAH LOOPZ R STARTPTR
KTHX
IZ IPTR IN MAH INSTRUCTIONS LIEK "!"?
GTFO
NOWAI
UPZ IPTR!!
KTHX
KTHX
BTW Variables for BF's tape
I HAS A LTAPE
I HAS A RTAPE
I HAS A LPTR
LOL LPTR R 0
I HAS A RPTR
LOL RPTR R 0
I HAS A CELL
LOL CELL R 0
BTW Reset instruction pointer to start
LOL IPTR R 0
BTW Start interpreting
IM IN YR LOOP
I HAS A THING
LOL THING R IPTR IN MAH INSTRUCTIONS
BTW Move tape head right
IZ THING LIEK ">"?
LOL LPTR IN MAH LTAPE R CELL
UPZ LPTR!!
IZ RPTR LIEK 0?
LOL CELL R 0
NOWAI
NERFZ RPTR!!
LOL CELL R RPTR IN MAH RTAPE
KTHX
KTHX
BTW Move tape head left
IZ THING LIEK "<"?
LOL RPTR IN MAH RTAPE R CELL
UPZ RPTR!!
IZ LPTR LIEK 0?
LOL CELL R 0
NOWAI
NERFZ LPTR!!
LOL CELL R LPTR IN MAH LTAPE
KTHX
KTHX
BTW Increment
IZ THING LIEK "+"?
UPZ CELL!!
KTHX
BTW Decrement
IZ THING LIEK "-"?
NERFZ CELL!!
KTHX
BTW Output produces numbers instead of ASCII characters
IZ THING LIEK "."?
VISIBLE CELL!
VISIBLE " "!
KTHX
BTW Input doesn't work because we can't convert characters to integers
BTW Oh well, it doesn't stop it being turing complete
BTW Start of loop
IZ THING LIEK "[" AND CELL LIEK 0?
LOL IPTR R IPTR IN MAH LOOPZ
KTHX
BTW End of loop
IZ THING LIEK "]" AND CELL NOT LIEK 0?
LOL IPTR R IPTR IN MAH LOOPZ
KTHX