Staq

From Esolang
Jump to: navigation, search
Staq.jpg

Staq is an esoteric programming language by User:Madk in which operations are done using a stack. It is characterized by its fairly unique take on program flow, which allows intertwined loops and instruction overrides among other oddities. The language has robust access to two separate double-ended stacks, and can be shown to be Turing-complete when using just one.

Commands

& place a new zero value on the top of the stack
x throw out the top stack value
X throw out the second stack value
i increment the top stack value
d decrement the top stack value
q square the top stack value
, bit shift the top stack value left
. bit shift the top stack value right
< rotate top stack value bits left
~ binary not operation on top stack value
@ swap the top and second stack values
$ move the top stack value to the bottom
s move the bottom stack value to the top
+ add the top and second stack values and place the result in a new value on top of the stack
- subtract the second from the top stack value
* multiply the top and second stack values
/ divide the top by the second stack value
% modulo the top by the second stack value
> boolean is the top value greater than the second, new value is put on top of the stack
= boolean is the top value equal to the second, new value is put on top of the stack
[ jump to corresponding ] if the top stack value is 0 (or if it does not exist)
] jump back to corresponding [ if the top stack value is greater than 0
( jump to corresponding ) if the top stack value is greater then 0
) jump back to corresponding ( if the top stack value is 0 (or if it does not exist)
? execute the following command if the top stack value is greater than 0
! execute the following command if the top stack value is 0
: output the topmost stack value to the console as a number
; output the topmost stack value to the console as a character
' put an inputted number on top of the stack
` put an inputted character on top of the stack
n put the total number of values currently in the stack into a new value on top of the stack
" print the following characters to the console, until another " is encountered
| swap the active and passive stacks
t copy the topmost value of the active stack and place it on top of the passive stack

You can also define functions by using the {} characters. For example,

{u &+X}

would cause all following instances of the character "u" to be replaced with the code "&+X" when interpreting. Note: {} can be nested. To ignore a character's assigned function and instead perform the default, precede the character in question with a '_'

_u


  • Default commands can be overridden.
  • Including a character itself inside its definition will result in recursion.
  • If a character is assigned blank data (for example, {*}) it would return to its default purpose. (In this case, * would become the normal multiplication operation rather than whatever inanity you've had assigned to it.)
  • Overriding { is generally a bad idea, though it is not illegal.
  • Defining a character inside its own definition may or may not result in weirdness.

Do something like this to make a comment:

&[ this is a comment ]x

Examples

Hello, world!

"Hello, world!"

Cat

`;

99 Bottles

{\&iiiqi;x}&iiiqiqdd
[i:" bottles of beer on the wall, ":" bottles of beer."\"Take one down, pass it around. "d:" bottles of beer on the wall."\d]
"1 bottle of beer on the wall, 1 bottle of beer."\"Take it down, pass it around. No more bottles of beer on the wall."\

Collatz sequence

{\&iiiqi;x}&&ii"Input a number to determine its Collatz sequence: "'
[d[si$i:\%($/Xs?)[$@i@*iX@d@s!]xd]i:\!]
"Total numbers in sequence: "si:

Fibonacci sequence

{\&iiiqi;x}"Calculating the first 24 numbers of the Fibonacci sequence."\
&i&i:\&iiqiqdd[d$:\+$Xss]

Deadfish implementation with Hello, world! example

&iiqqq&{o:&iiiqi;@X}{T-!@_x}{i_iT}{D_d}{d?DT}{sqT}{ks}{xi}{co}{>id}
iisiiiisiiiiiiiioiiiiiiiiiiiiiiiiiiiiiiiiiiiiioiiiiiiiooiiio
dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddo
dddddddddddddddddddddsddoddddddddoiiioddddddoddddddddo

Temperature conversion

&("Convert C -> F (input 0) or F -> C (input 1)? "'
(&iiqi&iiiq"How many degrees Centigrade? "'*XX/&iiqiiqdddd+"Result: ":" degrees Fahrenheit"xxxxx?)
[&iiiq&iiqi"How many degrees Fahrenheit? "'*XX/&iiqiiqdddd-"Result: ":" degrees Centigrade"xxxxx!]
&iiiqi;;xx)

Computational class

Explanation

Staq can be proven to be Turing-complete through a skewed form of reduction; a brainfuck program with finite length but unbounded values (which is enough for Turing completeness) can be reproduced in Staq by placing

{>|n?xtx|}{<n?xtx}{+i}{-d}{,`}{.;}&|&

at the beginning of the program. This allows an arbitrary memory tape size when moving to the right, but won't move left of the origin.

For a bounded tape that wraps, the code

&iiqqq[d&@]x{>s}{<$}{+i}{-d}{,`}{.;}

has a tape size of 256 which adjustable by altering the &iiqqq portion to generate a different number.

Hello, world! brainfuck example

{>|n?xtx|}{<n?xtx}{+i}{-d}{,`}{.;}&|&
>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.>>>++++++++[<++++>-]<.>>>++++++++++[<+++++++++>-]<---.<<<<.+++.------.--------.>>+.

External resources

Download Staq interpreter