Hi, I'm proud to provide you with a Befunge-93 interpreter written in Parrot! I'd like to thanks you all of the parrot team, for giving us such a marvelous toy to play with.
Note to Leon Brocard: There's a lot more to do in order to provide a Befunge-98 compliant interpreter, so don't worry! There's still a lot of fun waiting... :o) Jerome -- [EMAIL PROTECTED]
diff -urbN parrot.orig/languages/Befunge-93/Makefile parrot/languages/Befunge-93/Makefile --- parrot.orig/languages/Befunge-93/Makefile Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/Makefile Fri Aug 16 20:47:51 2002 @@ -0,0 +1,17 @@ +ASSEMBLE=perl ../../assemble.pl +PARROT=../../parrot + +test: build + $(PARROT) befunge.pbc test.bef + +build: befunge.pasm flow.pasm io.pasm load.pasm maths.pasm stack.pasm + $(ASSEMBLE) befunge.pasm > befunge.pbc + +clean: + rm -f core *.pbc *~ + +dist: clean + rm -f befunge.tgz + ( cd .. ; tar cvf befunge.tar Befunge-93 ) + gzip ../befunge.tar + mv ../befunge.tar.gz befunge.tgz diff -urbN parrot.orig/languages/Befunge-93/README parrot/languages/Befunge-93/README --- parrot.orig/languages/Befunge-93/README Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/README Fri Aug 16 20:52:11 2002 @@ -0,0 +1,82 @@ +DESCRIPTION +----------- +This is a Befunge interpreter written in Parrot assembler, version 0.01 + +This interpreter should be Befunge-93 compliant. This means the +playfield is limited to 80x25 and can hold *only bytes*. This means +that you can't fetch/store numbers greater than 255 or less than 0 in +the torus. + +You should compile the files with: + + $ make build + $ make test + +Then you can run your Befunge program with: + + $ ../../parrot befunge.pbc [-v] foo.bef + +The -v flag makes the befunge interpreter more verbose. + + +NOTES +----- +The files are the following: + befunge.pasm the main loop + load.pasm function to load the code from source file + flow.pasm handles the flow-control instructions + io.pasm handles the io related instructions + maths.pasm handles all the maths instructions + stack.pasm handles the stack operations as well as stack + instructions + Makefile a tiny, little Makefile to help (me) during + developement + test.bef a befunge script that test almost all the instructions + + +BUGS +---- +* The befunge program *should* be properly newline terminated because + of Parrot's I/O... +* The "input char" and "input int" instructions are a bit broken since + Parrot does not handle I/O very well... + + +TODO +---- +* more error checking +* better rand()/chr() methods +* more tests (with Perl and Test::Harness) +* debugging options +* use an array of arrays instead of an array of strings +* implement Befunge 98 + + +AUTHOR +------ +Jerome Quelin, <[EMAIL PROTECTED]> + + +ACKNOWLEDGEMENTS +---------------- +I would like to thank: +* Chris Pressey, creator of Befunge, who gave a whole new dimension to + both coding and obfuscating. +* Leon Brocard and Rafael Garcia-Suarez, for giving me this crazy + idea. +* Leon Brocard (again), because he told me he will help me with the + Befunge-98 version :o) +* Dan Sugalski and all the parrot folks for providing such a nice toy + to play with. + + +COPYRIGHT +--------- +This program is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + +SEE ALSO +-------- +* http://www.parrotcode.org +* http://www.catseye.mb.ca/esoteric/befunge/ + diff -urbN parrot.orig/languages/Befunge-93/README~ parrot/languages/Befunge-93/README~ --- parrot.orig/languages/Befunge-93/README~ Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/README~ Fri Aug 16 20:47:01 2002 @@ -0,0 +1,80 @@ +DESCRIPTION +----------- +This is a Befunge interpreter written in Parrot assembler, version 0.01 + +This interpreter should be Befunge-93 compliant. This means the +playfield is limited to 80x25 and can hold *only bytes*. This means +that you can't fetch/store numbers greater than 255 or less than 0 in +the torus. + +You should compile the files with: + + $ make build + $ make test + +Then you can run your Befunge program with: + + $ ../../parrot befunge.pbc [-v] foo.bef + +The -v flag makes the befunge interpreter more verbose. + + +NOTES +----- +The files are the following: + befunge.pasm the main loop + load.pasm function to load the code from source file + flow.pasm handles the flow-control instructions + io.pasm handles the io related instructions + maths.pasm handles all the maths instructions + stack.pasm handles the stack operations as well as stack + instructions + Makefile a tiny, little Makefile to help (me) during + developement + test.bef a befunge script that test almost all the instructions + + +BUGS +---- +The "input char" and "input int" instructions are a bit broken since +Parrot does not handle I/O very well... + + +TODO +---- +* more error checking +* better rand()/chr() methods +* more tests (with Perl and Test::Harness) +* debugging options +* use an array of arrays instead of an array of strings +* implement Befunge 98 + + +AUTHOR +------ +Jerome Quelin, <[EMAIL PROTECTED]> + + +ACKNOWLEDGEMENTS +---------------- +I would like to thank: +* Chris Pressey, creator of Befunge, who gave a whole new dimension to + both coding and obfuscating. +* Leon Brocard and Rafael Garcia-Suarez, for giving me this crazy + idea. +* Leon Brocard (again), because he told me he will help me with the + Befunge-98 version :o) +* Dan Sugalski and all the parrot folks for providing such a nice toy + to play with. + + +COPYRIGHT +--------- +This program is free software; you can redistribute it and/or modify +it under the same terms as Perl itself. + +SEE ALSO +-------- +* http://www.parrotcode.org +* http://www.catseye.mb.ca/esoteric/befunge/ + diff -urbN parrot.orig/languages/Befunge-93/befunge.pasm parrot/languages/Befunge-93/befunge.pasm --- parrot.orig/languages/Befunge-93/befunge.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/befunge.pasm Fri Aug 16 20:19:42 2002 @@ -0,0 +1,181 @@ + branch MAIN + +.include "flow.pasm" +.include "io.pasm" +.include "load.pasm" +.include "maths.pasm" +.include "stack.pasm" + +MAIN: + set I0, 0 + set I4, 0 # verbose mode +ARGV_NEXT: + inc I0 + set S10, P0[I0] + substr S11, S10, 0, 1 + ne S11, "-", ARGV_DONE + eq S10, "-v", ARGV_VERBOSE + branch ARGV_NEXT +ARGV_VERBOSE: + inc I4 + branch ARGV_NEXT +ARGV_DONE: + set S10, P0[I0] + save S10 + bsr LOAD + restore P1 # the playfield + new P2, .PerlArray # the stack + set I0, 0 # x coord of the PC + set I1, 0 # y coord of the PC + set I2, 1 # direction of the PC + set I5, 0 # flag (1=string-mode,2=bridge,3=end) + time N0 # random seed + mod N0, N0, .RANDMAX + set S0, " " # current instruction + set S1, P1[0] # current line + set S2, "" # user input + set S3, "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff" + +TICK: + substr S0, S1, I0, 1 + eq I4, 0, TICK_NOVERBOSE + bsr VERBOSE +TICK_NOVERBOSE: + eq S0, "\"", FLOW_TOGGLE_STRING_MODE + eq I5, 1, IO_PUSH_CHAR + eq I5, 2, MAIN_TRAMPOLINE + eq I5, 3, MAIN_END + + # Sole number. + lt S0, "0", NOT_NUM + le S0, "9", MATHS_PUSH_NUMBER +NOT_NUM: + + # Direction changing. + eq S0, "^", FLOW_GO_NORTH + eq S0, ">", FLOW_GO_EAST + eq S0, "v", FLOW_GO_SOUTH + eq S0, "<", FLOW_GO_WEST + eq S0, "?", FLOW_GO_AWAY + + # Flow control. + eq S0, "`", FLOW_COMPARE + eq S0, "_", FLOW_EW_IF + eq S0, "|", FLOW_NS_IF + eq S0, "#", FLOW_BRIDGE + eq S0, "@", FLOW_END + + # Math functions. + eq S0, "+", MATHS_ADD + eq S0, "-", MATHS_SUB + eq S0, "*", MATHS_MUL + eq S0, "/", MATHS_DIV + eq S0, "%", MATHS_MOD + eq S0, "!", MATHS_NOT + + # Stack operations. + eq S0, ":", STACK_DUP + eq S0, "$", STACK_POP + eq S0, "\\", STACK_SWAP + + # I/O operations. + eq S0, "&", IO_INPUT_INT + eq S0, "~", IO_INPUT_CHAR + eq S0, ".", IO_OUTPUT_INT + eq S0, ",", IO_OUTPUT_CHAR + eq S0, "g", IO_GET_VALUE + eq S0, "p", IO_PUT_VALUE + + # Unknow instruction. + branch MOVE_PC + +MAIN_TRAMPOLINE: + set I5, 0 # no more trampoline +MOVE_PC: + eq I2, 1, MOVE_EAST + eq I2, 2, MOVE_SOUTH + eq I2, 3, MOVE_WEST + # fallback MOVE_NORTH +MOVE_NORTH: + dec I1 + mod I1, I1, 25 + set S1, P1[I1] + branch TICK +MOVE_EAST: + inc I0 + mod I0, I0, 80 + branch TICK +MOVE_SOUTH: + inc I1 + mod I1, I1, 25 + set S1, P1[I1] + branch TICK +MOVE_WEST: + dec I0 + mod I0, I0, 80 + branch TICK + +MAIN_END: + end + +VERBOSE: + # Coordinates. + print "(" + print I0 + print "," + print I1 + print ")" + # Current char. + print " - '" + print S0 + print "' (ord=" + ord I10, S0 + print I10 + print ")" + # Direction. + print " dir=" + print I2 + # Flags: + set S10, " \"" + eq I5, 1, VERBOSE_PRINT_FLAG + set S10, " #" + eq I5, 2, VERBOSE_PRINT_FLAG + set S10, " @" + eq I5, 3, VERBOSE_PRINT_FLAG + set S10, " " +VERBOSE_PRINT_FLAG: + print S10 + # Stack. + print " stack=" + set I11, P2 + set I10, 0 + ge I10, I11, VERBOSE_STACK_END +VERBOSE_STACK_LOOP: + set I12, P2[I10] + print I12 + inc I10 + ge I10, I11, VERBOSE_STACK_END + print "," + branch VERBOSE_STACK_LOOP +VERBOSE_STACK_END: + print "\n" + ret + +DUMP_PLAYFIELD: + pushi + pushs + repeat S10, "-", 82 + concat S10, "\n" + print S10 + set I10, 0 +DUMP_NEXT_LINE: + set S11, P1[I10] + print "|" + print S11 + print "|\n" + inc I10 + lt I10, 25, DUMP_NEXT_LINE + print S10 + pops + popi + ret \ No newline at end of file diff -urbN parrot.orig/languages/Befunge-93/flow.pasm parrot/languages/Befunge-93/flow.pasm --- parrot.orig/languages/Befunge-93/flow.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/flow.pasm Fri Aug 16 20:25:30 2002 @@ -0,0 +1,106 @@ +# Go north. +# Befunge stack unchanged. +# delta <- (0,-1) +FLOW_GO_NORTH: + set I2, 0 + branch MOVE_PC + +# Go east. +# Befunge stack unchanged. +# delta <- (1,0) +FLOW_GO_EAST: + set I2, 1 + branch MOVE_PC + +# Go south. +# Befunge stack unchanged. +# delta <- (0,1) +FLOW_GO_SOUTH: + set I2, 2 + branch MOVE_PC + +# Go west. +# Befunge stack unchanged. +# delta <- (-1,0) +FLOW_GO_WEST: + set I2, 3 + branch MOVE_PC + +FLOW_GO_AWAY: + save 4 + bsr MATHS_RAND + pushi + restore I10 + set I2, I10 + save I2 + popi + restore I2 + branch MOVE_PC + +# East/West if. +# Befunge stack: +# before: ... b +# after: ... +# delta <- if (b) (-1,0) else (1,0) +FLOW_EW_IF: + bsr POP + restore I10 + eq I10, 0, FLOW_GO_EAST + branch FLOW_GO_WEST + +# North/South if. +# Befunge stack: +# before: ... b +# after: ... +# delta <- if (b) (0,-1) else (0,1) +FLOW_NS_IF: + bsr POP + restore I10 + eq I10, 0, FLOW_GO_SOUTH + branch FLOW_GO_NORTH + + +# Greater than. +# Befunge stack: +# before: ... a b +# after: ... a>b +# Result is either 1 or 0. +FLOW_COMPARE: + pushi + bsr POP + restore I10 + bsr POP + restore I11 + set I12, 1 + gt I11, I10, FLOW_COMPARE_TRUE + set I12, 0 +FLOW_COMPARE_TRUE: + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Toggle string mode. +# Befunge stack unchanged. +FLOW_TOGGLE_STRING_MODE: + eq I5, 1, FLOW_TOGGLE_STRING_MODE_OFF + set I5, 1 + branch MOVE_PC +FLOW_TOGGLE_STRING_MODE_OFF: + set I5, 0 + branch MOVE_PC + +# Trampoline. +# Befunge stack unchanged. +# Skip next instruction (pos < pos + delta) +FLOW_BRIDGE: + set I5, 2 + branch MOVE_PC + +# Stop. +# Befunge stack unchanged. +# End program. +FLOW_END: + set I5, 3 + branch MOVE_PC + \ No newline at end of file diff -urbN parrot.orig/languages/Befunge-93/io.pasm parrot/languages/Befunge-93/io.pasm --- parrot.orig/languages/Befunge-93/io.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/io.pasm Fri Aug 16 19:33:38 2002 @@ -0,0 +1,167 @@ +# Implement the chr() function. +# Generic method. +# Parrot stack: +# before: ... i +# after: ... c +# c = chr(i) +IO_CHR: + pushi + pushs + restore I10 + substr S10, S3, I10, 1 + save S10 + pops + popi + ret + +# String mode. +# Befunge stack: +# before: ... +# after: ... c +# i = ord(current char) +IO_PUSH_CHAR: + pushi + ord I10, S0 + save I10 + bsr PUSH + popi + branch MOVE_PC + +# Input integer. +# Befunge stack: +# before: ... +# after: ... i +# i = readint() +IO_INPUT_INT: + save S2 + pushi + pushs + restore S2 + length I10, S2 + gt I10, 0, IO_INPUT_INT_PARSE_INPUT + read S2, 1 + length I10, S2 +IO_INPUT_INT_PARSE_INPUT: + set I11, 0 + set S10, "" +IO_INPUT_INT_NEXT_CHAR: + substr S11, S2, I11, 1 + lt S11, "0", IO_INPUT_INT_NAN + gt S11, "9", IO_INPUT_INT_NAN + concat S10, S10, S11 + inc I11 + lt I11, I10, IO_INPUT_INT_NEXT_CHAR + set I10, 0 + set I11, 0 +IO_INPUT_INT_NAN: + substr S2, S2, I11, I10 + save I10 + bsr PUSH + pops + popi + branch MOVE_PC + +# Input character. +# Befunge stack: +# before: ... +# after: ... c +# c = getchar() +IO_INPUT_CHAR: + save S2 + pushi + pushs + restore S2 + length I10, S2 + gt I10, 0, IO_INPUT_CHAR_SUBSTR + read S2, 1 +IO_INPUT_CHAR_SUBSTR: + substr S10, S2, 0, 1 + length I10, S2 + substr S2, S2, 1, I10 + ord I10, S10 + save I10 + bsr PUSH + save S2 + pops + restore S2 + popi + branch MOVE_PC + +# Output integer. +# Befunge stack: +# before: ... i +# after: ... +# writeint(i) +IO_OUTPUT_INT: + pushi + bsr POP + restore I10 + print I10 + popi + branch MOVE_PC + +# Output character. +# Befunge stack: +# before: ... i +# after: ... +# writechar( chr(i) ) +IO_OUTPUT_CHAR: + pushs + bsr POP + bsr IO_CHR + restore S10 + print S10 + pops + branch MOVE_PC + +# Get a value from playfield. +# Befunge stack: +# before: ... x y +# after: ... i +# i = value_at(x,y) +IO_GET_VALUE: + pushi + pushs + bsr POP + restore I11 + bsr POP + restore I10 + set S10, P1[I11] + ord I12, S10, I10 + save I12 + bsr PUSH + pops + popi + branch MOVE_PC + +# Put a value in the playfield. +# Befunge stack: +# before: ... i x y +# after: ... +# value_at(x,y) = i +IO_PUT_VALUE: + pushi + pushs + bsr POP + restore I11 + set S10, P1[I11] # original line + bsr POP + restore I10 # offset + bsr POP + bsr IO_CHR + restore S11 # char to store + length I12, S10 + set S13, "" # First part + set S12, "" # Second part + substr S13, S10, 0, I10 + inc I10 + substr S12, S10, I10, I12 + set S14, "" + concat S14, S13 + concat S14, S11 + concat S14, S12 + set P1[I11], S14 + pops + popi + set S1, P1[I1] # Restore line, in case we changed the current line... + branch MOVE_PC diff -urbN parrot.orig/languages/Befunge-93/load.pasm parrot/languages/Befunge-93/load.pasm --- parrot.orig/languages/Befunge-93/load.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/load.pasm Fri Aug 16 17:32:15 2002 @@ -0,0 +1,65 @@ +# Load a file given as parameter. +# Parrot stack: +# before: ... filename +# after: ... PerlArray +# The perlarray is filled with the content of the file, 80x25. +LOAD: + pushi + pushs + pushp + restore S0 # Fetch the filename + open P0, S0, "<" + set S1, "" # Accumulator + new P1, .PerlArray # The playing field + +# Read the file. +LOAD_READ: + read S2, P0, 256 + length I0, S2 + le I0, 0, LOAD_EOF + concat S1, S2 + branch LOAD_READ + +# Split the buffer around its newlines. +LOAD_EOF: + close P0 + length I0, S1 # I0 =length of the buffer + set I1, 0 # I1 =ranges from 0 to I0 + set I2, 0 # I2 =beginning of current line + set I3, 0 # I3 =current line in the array + +LOAD_PARSE_BUFFER: + lt I0, I1, LOAD_END_BUFFER + substr S2, S1, I1, 1 + ne S2, "\n", LOAD_NONL + sub I4, I1, I2 + substr S3, S1, I2, I4 + add I2, I4 + inc I2 # Trailing newline + set P1[I3], S3 + inc I3 + +LOAD_NONL: + inc I1 + branch LOAD_PARSE_BUFFER + +# Fill/truncate playfield to 25 rows and 80 columns. +LOAD_END_BUFFER: + set P1, 25 + set I0, 0 + repeat S4, " ", 80 + +LOAD_TRUNCATE: + set S3, P1[I0] + concat S3, S4 + substr S3, S3, 0, 80 + set P1[I0], S3 + inc I0 + lt I0, 25, LOAD_TRUNCATE + +# Return the playfield + save P1 + popp + pops + popi + ret diff -urbN parrot.orig/languages/Befunge-93/maths.pasm parrot/languages/Befunge-93/maths.pasm --- parrot.orig/languages/Befunge-93/maths.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/maths.pasm Fri Aug 16 20:24:40 2002 @@ -0,0 +1,129 @@ +# Create a pseudo-random number. +# Parrot's stack: +# before: ... max +# after: ... rand +# 0 <= rand < max +.constant RANDMAX 65536.0 +MATHS_RAND: + pushi + restore I10 + mul N0, N0, 5.0 + add N0, N0, 1.0 + mod N0, N0, .RANDMAX + save N0 + pushn + restore N0 + set N10, I10 + mul N10, N0, N10 + div N10, N10, .RANDMAX + set I10, N10 + popn + save I10 + popi + ret + +# Push number on Befunge's stack. +# Befunge Stack: +# before: ... +# after: ... <number> +MATHS_PUSH_NUMBER: + pushi + set I10, S0 + save I10 + bsr PUSH + popi + branch MOVE_PC + +# Addition. +# Befunge Stack: +# before: ... a b +# after: ... a+b +MATHS_ADD: + pushi + bsr POP + restore I11 + bsr POP + restore I10 + add I12, I10, I11 + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Substraction. +# Befunge Stack: +# before: ... a b +# after: ... a-b +MATHS_SUB: + pushi + bsr POP + restore I11 + bsr POP + restore I10 + sub I12, I10, I11 + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Multiplication. +# Befunge Stack: +# before: ... a b +# after: ... a*b +MATHS_MUL: + pushi + bsr POP + restore I11 + bsr POP + restore I10 + mul I12, I10, I11 + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Division. +# Befunge Stack: +# before: ... a b +# after: ... a/b +MATHS_DIV: + pushi + bsr POP + restore I11 + bsr POP + restore I10 + div I12, I10, I11 + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Remainder. +# Befunge Stack: +# before: ... a b +# after: ... a mod b +MATHS_MOD: + pushi + bsr POP + restore I11 + bsr POP + restore I10 + mod I12, I10, I11 + save I12 + bsr PUSH + popi + branch MOVE_PC + +# Logical not. +# Befunge Stack: +# before: ... a +# after: ... not(a) +MATHS_NOT: + pushi + bsr POP + restore I10 + not I10, I10 + save I10 + bsr PUSH + popi + branch MOVE_PC \ No newline at end of file diff -urbN parrot.orig/languages/Befunge-93/stack.pasm parrot/languages/Befunge-93/stack.pasm --- parrot.orig/languages/Befunge-93/stack.pasm Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/stack.pasm Fri Aug 16 17:42:35 2002 @@ -0,0 +1,74 @@ +# Push an integer in Befunge's stack. +# The integer is popped from Parrot's stack. +# Generic method. +PUSH: + pushi + restore I6 + set I7, P2 + set P2[I7], I6 + popi + ret + +# Pop an integer from Befunge's stack. +# the integer is pushed on Parrot's stack. +# Generic method. +POP: + pushi + set I7, P2 + eq I7, 0, POP_EMPTY + dec I7 + set I6, P2[I7] + save I6 + set P2, I7 + popi + ret + +POP_EMPTY: + set I10, 0 + save I10 + popi + ret + +# Duplicate. +# Befunge stack: +# before: ... v +# after: ... v +STACK_DUP: + pushi + bsr POP + restore I10 + save I10 + bsr PUSH + save I10 + bsr PUSH + popi + branch MOVE_PC + +# Pop. +# Befunge stack: +# before: ... v +# after: ... +# Element is just discarded. +STACK_POP: + pushi + bsr POP + restore I10 + popi + branch MOVE_PC + +# Swap. +# Befunge stack: +# before: ... a b +# after: ... b a +STACK_SWAP: + pushi + bsr POP + restore I10 + bsr POP + restore I11 + save I10 + bsr PUSH + save I11 + bsr PUSH + popi + branch MOVE_PC \ No newline at end of file diff -urbN parrot.orig/languages/Befunge-93/test.bef parrot/languages/Befunge-93/test.bef --- parrot.orig/languages/Befunge-93/test.bef Thu Jan 1 01:00:00 1970 +++ parrot/languages/Befunge-93/test.bef Fri Aug 16 20:25:52 2002 @@ -0,0 +1,10 @@ +< p 04 "v" + ^ > +I @ _v + !, + _ 2! | : + . \- %2/36 `21 $ < ^< "<- then everything is ok!" +37 + ! # + 3 > + < v , _ ^# -8 : g20 "f you can see a 4 here ->" 8 4 + > :8- ^
