concat

How to:

1. Compile concat using make
2. Use ./main <source> to use concat in interpet mode
3. [Optional] Give gen arg to generate qbe IR and clang to compile to native binary. ./main <source> gen
   • This is very WIP.

Operators:

• t: value on the top of the stack
• ut: value under the top
• sp: stack pointer
• bst: value on the top of the back stack

Syntax	Job	Stack manipulation	Consume n
//...	comment	-	0
0-9	push number stack	t = value	0
"..."	push string to storage and push idx to stack	t = strIdx	0
.	dup	t = ut	0
:	dup two values	ut = t - 1, t = t	0
,	drop	sp--	1
;	swap	t = ut; ut = t	0
<-	stash n elements in back stack	for n in stack: bst = t;	n
->	pop n elements from back stack	for n in backStack: t = bst	n
+	plus	t = t + ut	2
-	minus	t = t - ut	2
*	mult	t = t * ut	2
/	plus	t = t / ut	2
%	mod	t = t % ut	2
<	less than	t = t < ut	2
>	greater than	t = t > ut	2
=	equality	t = t == ut	2
sout	print	out(t); sp--	1
do	start loop	t != 0	0
loop	check loop condition	t == 1	1
end	end body	-	0
putc	print char	out(t); sp--	1
print	print string	out(t); sp--	1
println	print string with new line	out("\n"); sp--	1
if	if start	t != 0	1
else	execute body if not true	-	0
endif	end if body	-	0