Search
Categories
Documents
Language::Befunge - a Befunge-98 interpreter
Language::Befunge - a Befunge-98 interpreter
use Language::Befunge;
my $interp = new Language::Befunge( "program.bf" );
$interp->run_code( "param", 7, "foo" );
Or, one can write directly:
my $interp = new Language::Befunge;
$interp->store_code( <<'END_OF_CODE' );
< @,,,,"foo"a
END_OF_CODE
$interp->run_code;
Enter the realm of topological languages!
This module implements the Funge-98 specifications on a 2D field (also
called Befunge). In particular, be aware that this is not a Trefunge
implementation (3D).
This Befunge-98 interpreters assumes the stack and Funge-Space cells
of this implementation are 32 bits signed integers (I hope your os
understand those integers). This means that the torus (or Cartesian
Lahey-Space topology to be more precise) looks like the following:
32-bit Befunge-98
=================
^
|-2,147,483,648
|
| x
<-----------+----------->
-2,147,483,648 | 2,147,483,647
|
y|2,147,483,647
v
This implementation is meant to work on unix-like systems, because
this interpreters only handle the character which ordinal value is 10
(also known as \n) as an End-Of-Line chars. In particular, no warranty
is made neither for Microsoft systems (\r\n) nor for Macs (\r).
This module also implements the Concurrent Funge semantics.
Create a new Befunge interpreter. If a filename is provided, then read
and store the content of the file in the cartesian Lahey space
topology of the interpreter.
All the following accessors are autoloaded.
Get or set the filename of the script.
Get or set the parameters of the script.
Get or set the current return value of the interpreter.
Get or set the kcounter (ie, the number of times the next instruction
will be repeated).
Set wether the interpreter should output debug messages.
Get or set the current Instruction Pointer processed.
Get or set the last Instruction Pointer (when @ or q
instructions are encountered).
Get or set the current set of IPs travelling in the Lahey space.
Get or set the set of IPs that will travel in the Lahey space
after the current tick.
Get the Lahey space object.
- move_curip( [regex] )
-
Move the current IP according to its delta on the LaheySpace topology.
-
If a regex ( a qr// object ) is specified, then IP will move as
long as the pointed character match the supplied regex.
-
Example: given the code ;foobar; (assuming the IP points on the
first ;) and the regex qr/[^;]/, the IP will move in order to
point on the r.
- abort( reason )
-
Abort the interpreter with the given reason, as well as the current
file and coordinate of the offending instruction.
- debug( LIST )
-
Issue a warning if the interpreter has DEBUG enabled.
- read_file( filename )
-
Read a file (given as argument) and store its code.
-
Side effect: clear the previous code.
- store_code( code )
-
Store the given code in the Lahey space.
-
Side effect: clear the previous code.
- run_code( [params] )
-
Run the current code. That is, create a new Instruction Pointer and
move it around the code.
-
Return the exit code of the program.
- next_tick( )
-
Finish the current tick and stop just before the next tick.
- process_ip( )
-
Process the current ip.
- op_num_push_number( )
-
Push the current number onto the TOSS.
- op_str_enter_string_mode( )
- op_str_fetch_char( )
- op_str_store_char( )
- op_math_addition( )
- op_math_substraction( )
- op_math_multiplication( )
- op_math_division( )
- op_math_remainder( )
- op_dir_go_east( )
- op_dir_go_west( )
- op_dir_go_north( )
- op_dir_go_south( )
- op_dir_go_away( )
- op_dir_turn_left( )
-
Turning left, like a car (the specs speak about a bicycle, but perl
is _so_ fast that we can speak about cars ;) ).
- op_dir_turn_right( )
-
Turning right, like a car (the specs speak about a bicycle, but perl
is _so_ fast that we can speak about cars ;) ).
- op_dir_reverse( )
- op_dir_set_delta( )
-
Hmm, the user seems to know where he wants to go. Let's trust him/her.
- op_decis_neg( )
- op_decis_gt( )
- op_decis_horiz_if( )
- op_decis_vert_if( )
- op_decis_cmp( )
- op_flow_space( )
-
A serie of spaces is to be treated as one NO-OP.
- op_flow_no_op( )
- op_flow_comments( )
-
Bypass comments in one tick.
- op_flow_trampoline( )
- op_flow_jump_to( )
- op_flow_repeat( )
- op_flow_kill_thread( )
- op_flow_quit( )
- op_stack_pop( )
- op_stack_duplicate( )
- op_stack_swap( )
- op_stack_clear( )
- op_block_open( )
- op_block_close( )
- op_bloc_transfer( )
- op_store_get( )
- op_store_put( )
- op_stdio_out_num( )
- op_stdio_out_ascii( )
- op_stdio_in_num( )
- op_stdio_in_ascii( )
- op_stdio_in_file( )
- op_stdio_out_file( )
- op_stdio_sys_exec( )
- op_sys_info( )
- op_spawn_ip( )
- op_lib_load( )
- op_lib_unload( )
- o
-
Write standard libraries.
Although this module comes with a full set of tests, maybe there are
subtle bugs - or maybe even I misinterpreted the Funge-98
specs. Please report them to me.
There are some bugs anyway, but they come from the specs:
- o
-
About the 18th cell pushed by the
y instruction: Funge specs just
tell to push onto the stack the size of the stacks, but nothing is
said about how user will retrieve the number of stacks.
- o
-
About the load semantics. Once a library is loaded, the interpreter is
to put onto the TOSS the fingerprint of the just-loaded library. But
nothing is said if the fingerprint is bigger than the maximum cell
width (here, 4 bytes). This means that libraries can't have a name
bigger than
0x80000000, ie, more than four letters with the first
one smaller than P (chr(80)).
-
Since perl is not so rigid, one can build libraries with more than
four letters, but perl will issue a warning about non-portability of
numbers greater than 0xffffffff.
Jerome Quelin, <jquelin@cpan.org>
I would like to thank Chris Pressey, creator of Befunge, who gave a
whole new dimension to both coding and obfuscating.
This program is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
- perl
- http://www.catseye.mb.ca/esoteric/befunge/
- http://dufflebunk.iwarp.com/JSFunge/spec98.html
Information
|
This site is currently in testing, it is not yet operating using the full database. Until it is officially launched you may wish to visit Help-Site Computer Manuals. After launch, this site (HelpSpy) will replace Help-Site. Information about the spider which is currently trawling the Internet looking for links to add to this directory can be found here. |
| 
