St*ck - brainf*ck with stack

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March 19th, 2010, 04:14 PM

delnan

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Other Language - St*ck - brainf*ck with stack

Being a big fan of esoterical languages, I recently ran into a precious piece of insanity called Stacked Brain****. I even started writing an interpreter for it in D. There are more bf-inspired languages with stack (Brainstack and Stackf*ck), but the first rather misses the idea of minimalism by having both cells and a stack (inc. commands for both), and the latter still has a memory cell and simply pushed/pops this cell.
Suddenly, the thought the this idea could be taken further emerged... a single stack - no (accessable) other memory - and only 8 commands of vanishingly small power to operate on it.
St*ck was fathered, and now I'd appreciate some comments on what I figured out so far, so the child may be born without malformations.
One note on turing completeness: I don't have any idea, but as the semantics are rather close to bf, just with a stack instead of a tape, it may be turing-complete.
----------

St*ck has a single Stack. If this stack is limited, what the limit is, and what size each item has, is up to the implementation. As with traditional brain****, formatting and non-command characters are ignored. So far, the commands are as following:

Code:

Command | Meaning
    ^   | push previously popped value, or 0
    v   | pop (remember for subsequent push)
    +   | increment top item
    -   | decrement top item
    .   | output top item as ASCII char (peek, i.e. do not pop)
    ,   | push input
    [   | jump past matching ] if top item == 0 (peek)
    ]   | jump back to matching [ if top item != 0 (peek)

As said, any feedback is welcome.

March 21st, 2010, 01:33 AM

Lux Perpetua

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Quote:

Originally Posted by delnan

As said, any feedback is welcome.

You might get a better response if you show some example programs. (And of course, you'll get a better feel for the language in the process of creating them.)

March 21st, 2010, 05:07 AM

delnan

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Well then, I'll stick to the traditional hello, World. As st*ck's "tape" is unlimited only on one side, but limited to one on the other, the clever "approximate all character values in one big loop" doesn't work. But loops are still useful.

Code:

// approximate "!" (dec 33 = 3x10 plus 3) by loop
+++ // set top item (loop counter) to 3
[
  v
  ++++++++++ // add 10 to top item
  ^ - // push loop counter and dec it
]
v +++ ^ // finish counting to !: 30 plus 3 = 33 = !
// now loop counter is 0 and ! is on the stack
^ // push new loop counter (old loop counter becomes next char)
// same principle for remaining chars: dlroW *space* *comma* olleH

// d = 100 = 10x10
++++++++++
[
  v
  ++++++++++
  ^
]
^

// l = 108 = 10x11 minus 2
++++++++++
[
  v
  +++++++++++
  ^
]
v -- ^^

// r = 114 = 11x10 plus 4
+++++++++++
[
  v
  ++++++++++
  ^
]
v +++ ^^

// o = 111 = 11x10 plus 1
+++++++++++
[
  v
  ++++++++++
  ^
]
v + ^^

// W = 87 = 9x10 minus 3
+++++++++
[
  v
  ++++++++++
  ^
]
v --- ^^

// space = 32 = 5x6 plus 2
+++++
[
  v
  ++++++
  ^
]
v ++ ^^

// comma = 44 = 4x11
++++
[
  v
  +++++++++++
  ^
]
^

// o again
+++++++++++
[
  v
  ++++++++++
  ^
]
v + ^^

// l = 108 = 11x10 minus 2
+++++++++++
[
  v
  ++++++++
  ^
]
v -- ^^

// l again
// as only the last item popped is preserved
/ /we cannot alter more than two items
// (character and loop counter) within one loop
// however, we can output the same item twice
// since the dot does not pop but peek

// e = 101 = 10x10 plus 1
++++++++++
[
  v
  ++++++++++
  ^
]
v + ^^

// H = 72 = 7x10 plus 2
+++++++
[
  v
  ++++++++++
  ^
]
v ++ ^^

// now, the stack contains "Hello *comma* *space* World!" (in reverse order)
. // output latest char: "H"
v // pop manually, as dot does only peek
// etc cetera:
.v // "e"
.  // "l" no pop because "Hello" has to l
.v // second "l"
.v // "o"
.v // comma
.v // space
.v // "W"
.v // "o"
.v // "r"
.v // "l"
.v // "!"

Untested, of course, since there is no implementation.
And I wouldn't be to surprised if there is a more efficient way...

Other Language - Stck - brainfck with stack

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