Crazy J/Hello, world!

Crazy J examples

Hello, world!

Lambda calculus code

TODO

Tricks for minimize

TODO

Brainfuck mimic syntax

TODO

Making a polyglot program

There's a simple approach to make our program a Crazy J+Brainfuck polyglot:

   [-.[, CRAZY J PROGRAM ][,,]]+[ BRAINFUCK PROGRAM >]
   \__________________________/ \____________________/
            section 1                  section 2

How does it work? If the code is executed by Brainfuck interpreter, the first section of code is skipped because mem[0] is zero. Then the current cell is incremented and the second section is executed. We have to make sure that it wouldn't loop forever, so we move the pointer to knowingly zero cell ([-] could be used as well).

If the code is executed by Crazy J interpreter, the function inside the first section gets two extra arguments: + and the whole second section parsed as Crazy J code (which probably makes no sense). Two extra arguments can't be just dropped (we have no cancellative combinators), but since the input doesn't matter, extra arguments can be combined with the input. The boilerplate code from the diagram above does exactly that.

Rail (data structure) should be avoided in brainfuck section or used in modified form like this: [>+->] (because [>>] is not a valid code fragment in Crazy J).

The final result

[-.[-.+<,->[-.][,-][-.+<,->.[,-][-.+<,-->++<->+[-[--][,-]]]<.->[-.[-.+<,->.[,-]][-[-.],[-.[<.-->+[,-].]<,,][-.]<.-]][,.].][-[-.[-[-[-.]][.+][-,][-.+<,>+<,->[--++][-,-]][<.-->,[-.[<.-->+[,-].]<,,][-.][-[.+<,-]+[-[--++]+]-[-[-[-.+<,-]++]+[<--->[,-]]]]]]][<.-->.[,[,[<.-->,[-.[<.-->+[,-].]<,,>][-.][-.+<,->.[,-]<.->[-.<-->[.+][-,]][-[--[-.]+]+,<-->++-+].]<.-,>[-[-.[-[-.+<,-->++]+[<--->[,-]]]][<.-->,[<.-->[<.--->[.+][-,]]-[<.-->,[-.[<.-->+[,-].]<,,][-.]<.-]<,][-.]][-.+<,->.[,-]]+]<,>[-[-[-.+<,-]++]+[-[--][,-]]]][<.-->,[-.[<.-->+[,-].]<,,][-.]]][-.[-.+<,->.[,-]]<->[-.+<,-->++<->+[-[--][,-]]<.-][<.-->,[-.[<.-->+[,-].]<,,][-.]][-.][-[-.<-][.+][-,]][<.-->[-.[-.[-.<-.->.<->+-][,,]]][-.,[-.<-,]][<.-->,[<.-,,,][-.]]]++[-.[<.-->+[,-].][-.[-.+<,>+<,->[--++][-,-]<.->++.]<,]][-.+<,->.[,-]<.->[<.-->,[-.[<.-->+[,-].]<,,][-.]<.][-[-.+<,-->++]+[<--->[,-]]]+][-.+<,->.[,-]<.->[<.--->[.+][-,]][--[-.]+<->+,<-->++-+][<.-->,[-.[<.-->+[,-].]<,,][-.]<,]][-[.[<.-->,[-.[<.-->+[,-].]<,,][-.]]],[-.+<,->.[,-][-.+<,-->++<->+[-[--][,-]]]]+[-.+<,->.[,-]]][-.+<,->.[,-][-[-.+<,-->++]+[-[--][,-]]]<.->[-.[-.+<,->.[,-]][<.-->,[-.[<.-->+[,-].]<,,][-.]<.-]][,.].]]][-.+<,-->++<->+[-[--][,-]]<.->[-.[-.+<,->.[,-]][-.[<.-->,[-.[<.-->+[,-].]<,,][-.]]<->+<,]][-.].]][,-][-.[-.]]][<.-->,[-.[<.-->+[,-].]<,,][-.]<.->[-.+<,->.[,-]][-.+<,->.[,-]<.->,[-[-.+<,-->++]+[<--->[,-]]]+].][<.-->,[-.[<.-->+[,-].]<,,][-.][-.[-.+<,->.[,-]]<->[-.+<,-<->++<->+[-[--][,-]]<.-][<.--->[.+][-,]],.]]<,][,,]]+[+++++[>++++++[->++>+++>+++>+<<<<]>>-<<<-]>>.[--------<+++++>]>-.>..+++.<<<-.>>>>----.<++++++++.--------.+++.------.<-.<<<+++++[>--<<++>-]>-.<<.>]