Brainfuck implementation in `sed`

gistfile1.txt

#!/bin/sed -rf
# Sedfuck - brainfuck interpreter in sed.
# Written by Jonas Höglund (FireFly, firefly.nu).

h
s/^(.|[^.])*$/0/

	# Setup some memory.
s/0/0000000000/g
#s/0/0000000000/g
#s/0/0000000000/g
s/0/\x0/g

x

s/[{}]//g	# Strip braces.
	# Transform [] to {} (use {} for looping).
y/\[\]/{}/
s/[^-+<>{},\.]//g	# Strip non-instructions.
s/$/q/	# Add q to end of program ('quit' instruction).

:parse
#l;x;l;x

/^\+/ {
	x
	/^\xff/ {	# To not collide with the later s/^0/1/!
		s/^\xff/\x0/
		x
		b next
	}
	
	s/^\xfe/\xff/
	s/^\xfd/\xfe/
	s/^\xfc/\xfd/
	s/^\xfb/\xfc/
	s/^\xfa/\xfb/
	s/^\xf9/\xfa/
	s/^\xf8/\xf9/
	s/^\xf7/\xf8/
	s/^\xf6/\xf7/
	s/^\xf5/\xf6/
	s/^\xf4/\xf5/
	s/^\xf3/\xf4/
	s/^\xf2/\xf3/
	s/^\xf1/\xf2/
	s/^\xf0/\xf1/
	s/^\xef/\xf0/
	s/^\xee/\xef/
	s/^\xed/\xee/
	s/^\xec/\xed/
	s/^\xeb/\xec/
	s/^\xea/\xeb/
	s/^\xe9/\xea/
	s/^\xe8/\xe9/
	s/^\xe7/\xe8/
	s/^\xe6/\xe7/
	s/^\xe5/\xe6/
	s/^\xe4/\xe5/
	s/^\xe3/\xe4/
	s/^\xe2/\xe3/
	s/^\xe1/\xe2/
	s/^\xe0/\xe1/
	s/^\xdf/\xe0/
	s/^\xde/\xdf/
	s/^\xdd/\xde/
	s/^\xdc/\xdd/
	s/^\xdb/\xdc/
	s/^\xda/\xdb/
	s/^\xd9/\xda/
	s/^\xd8/\xd9/
	s/^\xd7/\xd8/
	s/^\xd6/\xd7/
	s/^\xd5/\xd6/
	s/^\xd4/\xd5/
	s/^\xd3/\xd4/
	s/^\xd2/\xd3/
	s/^\xd1/\xd2/
	s/^\xd0/\xd1/
	s/^\xcf/\xd0/
	s/^\xce/\xcf/
	s/^\xcd/\xce/
	s/^\xcc/\xcd/
	s/^\xcb/\xcc/
	s/^\xca/\xcb/
	s/^\xc9/\xca/
	s/^\xc8/\xc9/
	s/^\xc7/\xc8/
	s/^\xc6/\xc7/
	s/^\xc5/\xc6/
	s/^\xc4/\xc5/
	s/^\xc3/\xc4/
	s/^\xc2/\xc3/
	s/^\xc1/\xc2/
	s/^\xc0/\xc1/
	s/^\xbf/\xc0/
	s/^\xbe/\xbf/
	s/^\xbd/\xbe/
	s/^\xbc/\xbd/
	s/^\xbb/\xbc/
	s/^\xba/\xbb/
	s/^\xb9/\xba/
	s/^\xb8/\xb9/
	s/^\xb7/\xb8/
	s/^\xb6/\xb7/
	s/^\xb5/\xb6/
	s/^\xb4/\xb5/
	s/^\xb3/\xb4/
	s/^\xb2/\xb3/
	s/^\xb1/\xb2/
	s/^\xb0/\xb1/
	s/^\xaf/\xb0/
	s/^\xae/\xaf/
	s/^\xad/\xae/
	s/^\xac/\xad/
	s/^\xab/\xac/
	s/^\xaa/\xab/
	s/^\xa9/\xaa/
	s/^\xa8/\xa9/
	s/^\xa7/\xa8/
	s/^\xa6/\xa7/
	s/^\xa5/\xa6/
	s/^\xa4/\xa5/
	s/^\xa3/\xa4/
	s/^\xa2/\xa3/
	s/^\xa1/\xa2/
	s/^\xa0/\xa1/
	s/^\x9f/\xa0/
	s/^\x9e/\x9f/
	s/^\x9d/\x9e/
	s/^\x9c/\x9d/
	s/^\x9b/\x9c/
	s/^\x9a/\x9b/
	s/^\x99/\x9a/
	s/^\x98/\x99/
	s/^\x97/\x98/
	s/^\x96/\x97/
	s/^\x95/\x96/
	s/^\x94/\x95/
	s/^\x93/\x94/
	s/^\x92/\x93/
	s/^\x91/\x92/
	s/^\x90/\x91/
	s/^\x8f/\x90/
	s/^\x8e/\x8f/
	s/^\x8d/\x8e/
	s/^\x8c/\x8d/
	s/^\x8b/\x8c/
	s/^\x8a/\x8b/
	s/^\x89/\x8a/
	s/^\x88/\x89/
	s/^\x87/\x88/
	s/^\x86/\x87/
	s/^\x85/\x86/
	s/^\x84/\x85/
	s/^\x83/\x84/
	s/^\x82/\x83/
	s/^\x81/\x82/
	s/^\x80/\x81/
	s/^\x7f/\x80/
	s/^\~/\x7f/
	s/^\}/~/
	s/^\|/}/
	s/^\{/|/
	s/^z/{/
	s/^y/z/
	s/^x/y/
	s/^w/x/
	s/^v/w/
	s/^u/v/
	s/^t/u/
	s/^s/t/
	s/^r/s/
	s/^q/r/
	s/^p/q/
	s/^o/p/
	s/^n/o/
	s/^m/n/
	s/^l/m/
	s/^k/l/
	s/^j/k/
	s/^i/j/
	s/^h/i/
	s/^g/h/
	s/^f/g/
	s/^e/f/
	s/^d/e/
	s/^c/d/
	s/^b/c/
	s/^a/b/
	s/^`/a/
	s/^_/`/
	s/^\^/_/
	s/^\]/\^/
	s/^\\/\]/
	s/^\[/\\/
	s/^Z/\[/
	s/^Y/Z/
	s/^X/Y/
	s/^W/X/
	s/^V/W/
	s/^U/V/
	s/^T/U/
	s/^S/T/
	s/^R/S/
	s/^Q/R/
	s/^P/Q/
	s/^O/P/
	s/^N/O/
	s/^M/N/
	s/^L/M/
	s/^K/L/
	s/^J/K/
	s/^I/J/
	s/^H/I/
	s/^G/H/
	s/^F/G/
	s/^E/F/
	s/^D/E/
	s/^C/D/
	s/^B/C/
	s/^A/B/
	s/^@/A/
	s/^\?/@/
	s/^>/\?/
	s/^=/>/
	s/^</=/
	s/^;/</
	s/^:/;/
	s/^9/:/
	s/^8/9/
	s/^7/8/
	s/^6/7/
	s/^5/6/
	s/^4/5/
	s/^3/4/
	s/^2/3/
	s/^1/2/
	s/^0/1/
	s/^\//0/
	s/^\./\//
	s/^\-/\./
	s/^,/\-/
	s/^\+/,/
	s/^\*/\+/
	s/^\)/\*/
	s/^\(/\)/
	s/^'/\(/
	s/^\&/'/
	s/^%/\&/
	s/^\$/%/
	s/^#/\$/
	s/^"/#/
	s/^!/"/
	s/^ /!/
	s/^\x1f/ /
	s/^\x1e/\x1f/
	s/^\x1d/\x1e/
	s/^\x1c/\x1d/
	s/^\x1b/\x1c/
	s/^\x1a/\x1b/
	s/^\x19/\x1a/
	s/^\x18/\x19/
	s/^\x17/\x18/
	s/^\x16/\x17/
	s/^\x15/\x16/
	s/^\x14/\x15/
	s/^\x13/\x14/
	s/^\x12/\x13/
	s/^\x11/\x12/
	s/^\x10/\x11/
	s/^\xf/\x10/
	s/^\xe/\xf/
	s/^\xd/\xe/
	s/^\xc/\xd/
	s/^\xb/\xc/
	s/^\xa/\xb/
	s/^\x9/\xa/
	s/^\x8/\x9/
	s/^\x7/\x8/
	s/^\x6/\x7/
	s/^\x5/\x6/
	s/^\x4/\x5/
	s/^\x3/\x4/
	s/^\x2/\x3/
	s/^\x1/\x2/
	s/^\x0/\x1/
	x
}
/^-/ {
	x
	/^\x0/ {	# See '+' above.
		s/^\x0/\xff/
		x
		b next
	}
	
	s/^\x1/\x0/
	s/^\x2/\x1/
	s/^\x3/\x2/
	s/^\x4/\x3/
	s/^\x5/\x4/
	s/^\x6/\x5/
	s/^\x7/\x6/
	s/^\x8/\x7/
	s/^\x9/\x8/
	s/^\xa/\x9/
	s/^\xb/\xa/
	s/^\xc/\xb/
	s/^\xd/\xc/
	s/^\xe/\xd/
	s/^\xf/\xe/
	s/^\x10/\xf/
	s/^\x11/\x10/
	s/^\x12/\x11/
	s/^\x13/\x12/
	s/^\x14/\x13/
	s/^\x15/\x14/
	s/^\x16/\x15/
	s/^\x17/\x16/
	s/^\x18/\x17/
	s/^\x19/\x18/
	s/^\x1a/\x19/
	s/^\x1b/\x1a/
	s/^\x1c/\x1b/
	s/^\x1d/\x1c/
	s/^\x1e/\x1d/
	s/^\x1f/\x1e/
	s/^ /\x1f/
	s/^!/ /
	s/^"/!/
	s/^#/"/
	s/^\$/#/
	s/^%/\$/
	s/^\&/%/
	s/^'/\&/
	s/^\(/'/
	s/^\)/\(/
	s/^\*/\)/
	s/^\+/\*/
	s/^,/\+/
	s/^\-/,/
	s/^\./\-/
	s/^\//\./
	s/^0/\//
	s/^1/0/
	s/^2/1/
	s/^3/2/
	s/^4/3/
	s/^5/4/
	s/^6/5/
	s/^7/6/
	s/^8/7/
	s/^9/8/
	s/^:/9/
	s/^;/:/
	s/^</;/
	s/^=/</
	s/^>/=/
	s/^\?/>/
	s/^@/\?/
	s/^A/@/
	s/^B/A/
	s/^C/B/
	s/^D/C/
	s/^E/D/
	s/^F/E/
	s/^G/F/
	s/^H/G/
	s/^I/H/
	s/^J/I/
	s/^K/J/
	s/^L/K/
	s/^M/L/
	s/^N/M/
	s/^O/N/
	s/^P/O/
	s/^Q/P/
	s/^R/Q/
	s/^S/R/
	s/^T/S/
	s/^U/T/
	s/^V/U/
	s/^W/V/
	s/^X/W/
	s/^Y/X/
	s/^Z/Y/
	s/^\[/Z/
	s/^\\/\[/
	s/^\]/\\/
	s/^\^/\]/
	s/^_/\^/
	s/^`/_/
	s/^a/`/
	s/^b/a/
	s/^c/b/
	s/^d/c/
	s/^e/d/
	s/^f/e/
	s/^g/f/
	s/^h/g/
	s/^i/h/
	s/^j/i/
	s/^k/j/
	s/^l/k/
	s/^m/l/
	s/^n/m/
	s/^o/n/
	s/^p/o/
	s/^q/p/
	s/^r/q/
	s/^s/r/
	s/^t/s/
	s/^u/t/
	s/^v/u/
	s/^w/v/
	s/^x/w/
	s/^y/x/
	s/^z/y/
	s/^\{/z/
	s/^\|/{/
	s/^\}/|/
	s/^\~/}/
	s/^\x7f/~/
	s/^\x80/\x7f/
	s/^\x81/\x80/
	s/^\x82/\x81/
	s/^\x83/\x82/
	s/^\x84/\x83/
	s/^\x85/\x84/
	s/^\x86/\x85/
	s/^\x87/\x86/
	s/^\x88/\x87/
	s/^\x89/\x88/
	s/^\x8a/\x89/
	s/^\x8b/\x8a/
	s/^\x8c/\x8b/
	s/^\x8d/\x8c/
	s/^\x8e/\x8d/
	s/^\x8f/\x8e/
	s/^\x90/\x8f/
	s/^\x91/\x90/
	s/^\x92/\x91/
	s/^\x93/\x92/
	s/^\x94/\x93/
	s/^\x95/\x94/
	s/^\x96/\x95/
	s/^\x97/\x96/
	s/^\x98/\x97/
	s/^\x99/\x98/
	s/^\x9a/\x99/
	s/^\x9b/\x9a/
	s/^\x9c/\x9b/
	s/^\x9d/\x9c/
	s/^\x9e/\x9d/
	s/^\x9f/\x9e/
	s/^\xa0/\x9f/
	s/^\xa1/\xa0/
	s/^\xa2/\xa1/
	s/^\xa3/\xa2/
	s/^\xa4/\xa3/
	s/^\xa5/\xa4/
	s/^\xa6/\xa5/
	s/^\xa7/\xa6/
	s/^\xa8/\xa7/
	s/^\xa9/\xa8/
	s/^\xaa/\xa9/
	s/^\xab/\xaa/
	s/^\xac/\xab/
	s/^\xad/\xac/
	s/^\xae/\xad/
	s/^\xaf/\xae/
	s/^\xb0/\xaf/
	s/^\xb1/\xb0/
	s/^\xb2/\xb1/
	s/^\xb3/\xb2/
	s/^\xb4/\xb3/
	s/^\xb5/\xb4/
	s/^\xb6/\xb5/
	s/^\xb7/\xb6/
	s/^\xb8/\xb7/
	s/^\xb9/\xb8/
	s/^\xba/\xb9/
	s/^\xbb/\xba/
	s/^\xbc/\xbb/
	s/^\xbd/\xbc/
	s/^\xbe/\xbd/
	s/^\xbf/\xbe/
	s/^\xc0/\xbf/
	s/^\xc1/\xc0/
	s/^\xc2/\xc1/
	s/^\xc3/\xc2/
	s/^\xc4/\xc3/
	s/^\xc5/\xc4/
	s/^\xc6/\xc5/
	s/^\xc7/\xc6/
	s/^\xc8/\xc7/
	s/^\xc9/\xc8/
	s/^\xca/\xc9/
	s/^\xcb/\xca/
	s/^\xcc/\xcb/
	s/^\xcd/\xcc/
	s/^\xce/\xcd/
	s/^\xcf/\xce/
	s/^\xd0/\xcf/
	s/^\xd1/\xd0/
	s/^\xd2/\xd1/
	s/^\xd3/\xd2/
	s/^\xd4/\xd3/
	s/^\xd5/\xd4/
	s/^\xd6/\xd5/
	s/^\xd7/\xd6/
	s/^\xd8/\xd7/
	s/^\xd9/\xd8/
	s/^\xda/\xd9/
	s/^\xdb/\xda/
	s/^\xdc/\xdb/
	s/^\xdd/\xdc/
	s/^\xde/\xdd/
	s/^\xdf/\xde/
	s/^\xe0/\xdf/
	s/^\xe1/\xe0/
	s/^\xe2/\xe1/
	s/^\xe3/\xe2/
	s/^\xe4/\xe3/
	s/^\xe5/\xe4/
	s/^\xe6/\xe5/
	s/^\xe7/\xe6/
	s/^\xe8/\xe7/
	s/^\xe9/\xe8/
	s/^\xea/\xe9/
	s/^\xeb/\xea/
	s/^\xec/\xeb/
	s/^\xed/\xec/
	s/^\xee/\xed/
	s/^\xef/\xee/
	s/^\xf0/\xef/
	s/^\xf1/\xf0/
	s/^\xf2/\xf1/
	s/^\xf3/\xf2/
	s/^\xf4/\xf3/
	s/^\xf5/\xf4/
	s/^\xf6/\xf5/
	s/^\xf7/\xf6/
	s/^\xf8/\xf7/
	s/^\xf9/\xf8/
	s/^\xfa/\xf9/
	s/^\xfb/\xfa/
	s/^\xfc/\xfb/
	s/^\xfd/\xfc/
	s/^\xfe/\xfd/
	s/^\xff/\xfe/
	
	x
}
/^</ {
	x
	s/((.|[^.])*)(.|[^.])$/\3\1/	# Rotate mem to the right. (MP--)
	x
}
/^>/ {
	x
	s/^(.|[^.])((.|[^.])*)$/\2\1/	# Rotate mem to the left. (MP++)
	x
}
/^\{/ {	# '['; start of loop.
	x
	/^\x0/ {	# If curr mem cell is zero:
		s/^/-:/	# Insert a counter to keep track of nested looping depth.
		
		:loopCountStart
		x
		s/^(.)(.*)$/\2\1/	# IP++
		/^\{/ {
			x
			s/^/-/	# Increase loop depth.
			x
		}
		/^}/ {
			x
			s/^-//	# Decrease loop depth.
			x
		}
		x
		
		/^-/ b loopCountStart
		s/^://	# Strip leading colon (temp to separate loopcount from mem).
	}
	x
}
/^}/ {	# ']'; end of loop.
	x
	/^\x0/ !{	# If curr mem cell is nonzero:
		s/^/-:/	# Insert a counter to keep track of nested looping depth.
		
		:loopCountEnd
		x
		s/^(.*)(.)$/\2\1/	# IP--
		/^\{/ {
			x
			s/^-//	# Decrease loop depth.
			x
		}
		/^}/ {
			x
			s/^/-/	# Increase loop depth.
			x
		}
		x
		
		/^-/ b loopCountEnd
		s/^://	# Strip leading colon (temp to separate loopcount from mem).
	}
	x
}
/^\./ {
	x;p;x
}
/^,/ { }	# I/O - unimplemented.
/^q/ {
	x
	s/(.|[^.])/&, /g	# Neater memory output.
	s/, $//		# Strip the trailing ', '.
	s/^(.|[^.])*$/{ & }/	# Contain output in bracers.
	
#	d	# Delete the standard output!
	q
}

:next
s/^(.)(.*)$/\2\1/	# Rotate commands to the left.
b parse