phil2bf

This is a compiler I wrote that compiles a language I created into Brainfuck.

Download the source : compile.c.

The parser is very simple. The source file is parsed into tokens, separated by spaces.

FizzBuzz example :

char three zero three
char five zero five

char num1 set num1 '0
char num2 set num2 '0

char count set count 40
while count
	dec count
	
	char out
	
	inc num2
	equal out num2 ':
	ifz out
		set num2 '0
		inc num1
	end
	
	char fizzbuzz zero fizzbuzz
	
	inc three
	equal out three 3
	ifz out
		zero three
		print Fizz
		inc fizzbuzz
	end
	
	inc five
	equal out five 5
	ifz out
		zero five
		print Buzz
		inc fizzbuzz
	end
	
	ifnotz fizzbuzz
		char zero
		equal zero num1 '0
		ifnotz zero
			put num1
		end
		put num2
	end
	
	print \n
end

Which is compiled into the following Brainfuck code :

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

Commands

Commands may be split into multiple lines or can be written all in the same line. That is, the following are equivalent :

char hello zero hello inc hello

char hello
zero hello
inc hello

char
hello
zero
hello
inc
hello

My compiler implements many commands that make it easier to create Brainfuck programs :

char coucou

Creates a variable named coucou.

set coucou 123

Assigns the coucou variable to 123.

set coucou 'A

Assigns the coucou variable to 65.

copy coucou hello

Copies hello into coucou.

move coucou hello

Moves hello into coucou.

zero coucou

Resets the coucou variable to zero.

inc coucou

Increments the coucou variable.

incby coucou 5

Increments the coucou variable by 5.

dec coucou

Decrements the coucou variable.

decby coucou 5

Decrements the coucou variable by 5.

equal out coucou hello

Tests if coucou and hello are equal and stores the result into out.

equal out coucou 5

Tests if coucou equals 5 and stores the result into out.

equal out coucou 'A

Tests if coucou equals 65 and stores the result into out.

greater out coucou hello

Tests if coucou is greater than hello and stores the result into out.

greater out coucou 5

Tests if coucou is greater than 5 and stores the result into out.

greater out coucou 'A

Tests if coucou is greater than 65 and stores the result into out.

flip coucou

Flips the coucou variable : nonzero becomes zero and zero becomes one.

get coucou

Inputs a char and stores it into coucou.

put coucou

Outputs the char stored into coucou.

print Hello,\ World!\n

Prints Hello, World!.

Loops

All loops follow the same syntax :

while coucou ... end

This loops while coucou is nonzero.

... may be any tokens.

This prints A five times :

char count
set count 5
while count
	dec count
	print A
end
print \n

It may also be written into a single line :

char count set count 5 while count dec count print A end print \n

Ifs

Ifs are loops that run only once.

There are four kinds of ifs :

• if coucou ... end
• ifnot coucou ... end
• ifz coucou ... end
• ifnotz coucou ... end

The ifs ending with z clear their condition after they are run.

Use them to save memory.

The two other ifs make a copy of their condition and leave the original untouched.

if tests if the condition is nonzero and ifnot tests if the condition is zero.

Blocks

Loops have their own set of variables.

If you want to create variables not accessible from outside your code, use blocks :

block
	char x
	set x 'X
end
char y
put y
print \n

This will print X because the two variables share the same position in memory.

Arrays

To create an array, use the array command.

array str 4

This creates variables str, str+1, str+2 and str+3.

To navigate arrays, use the left and right commands.

right and left shift every variable.

This prints A :

array str 2
set str+1 'A
right 1
put str

This also prints A :

char a
char b
set b 'A
right 1
put a

Because a now points to b.

To start using normal variables again (and print), make sure you are back at the start of your array.

Strings

To more easily work with strings, use the read and write commands.

This reads a string and prints it back when you press Enter :

array str 10
read str '\n
write str

The second argument to read specifies when to stop reading. Here, it stops at a newline. It must be a decimal number or a character preceded by an apostrophe.

Internally, strings start and end with null bytes. So array size 10 means a maximum of 8 bytes.

Example

This code does a ROT13 :

char loop
set loop 1
while loop
	char input
	get input
	equal loop input 10
	flip loop
	if loop
		# A-Z to a-z
		char beforeZ
		greater beforeZ 91 input
		if beforeZ
			incby input 32
		end
		
		incby input 13
		
		# after z
		char afterz
		greater afterz input 122
		if afterz
			decby input 26
		end
		
		# a-z to A-Z
		if beforeZ
			decby input 32
		end
		
		put input
	end
end
print \n

This reads your name and prints it back with "Hello" before it :

print Your\ name\ :\ #
array name 10
read name '\n
print Hello,\ #
ifnot name+1
	print World
end
write name
print !\n