# @tention!

From Esolang

Created by User:Hiant, Fading Entity in November of 2010, **@tention!**, better known as **@!**, is based around the idea of a language where all data structures are queues. Below are the commands, their internal representations (as queues!) and a brief description. Note: the " operator is the identity function, and only exists internally.

Commands: (ABC): Description: AB= (AB=) Assignment Operator (sets A to B) This produces a new copy of B called A. AB_ (AB_) Alias Operator (A now represents B) A, (A,") Undefines A, freeing up memory space. (f(x)) (\"") Lambda Statements (One var only, x) AB> (AB>) Dequeues from A into B AB< (AB<) Enqueues B to Queue A A~ (A~") Dequeues from A, then Enqueues to A +, -, *, / (AB+) Common math statements, work only on integers (Reverse Polish) @ (@"") The empty Queue, for constructing new Queues $ ($"") Output Queue (Enqueue results in output) & (&"") Input Queue (All input is enqueued) % (%"") Execution Queue. Represents the Queue of all unexecuted commands. A{} (A{}) Repeats Commands in {} A times. If A is zero, {} is not executed. ; (;"") Line separator A! (A!") Returns Length of A A` (A`") Peeks into, but does not Dequeue from, A A' (A'") Character Literal. A is interpreted as its ASCII value. A? (A?") Returns 1 if A is not 0 or @, otherwise 0. A[] (A[]) Repeats [] while A is 'true'. AB# (AB#) Equality (A equals B) returns 1 or 0 AB^ (AB^) Applies Function B to A (A is interpreted as x in f(x) in B) : (:":) Enclose comments.

## Contents

## Language Overview

Some peculiarities exist in @!.

- ALL variables are global, aka no variable scope.
- Lambda statements may have only one variable, x. As such, no variable may be named x.
- All variables are single characters. Case-specific.
- Integer literals are allowed only as single digits.

## Example Programs

### Turing Completeness Proof

- Creating the Array (size 256):

D@=; T2=; Q(x{TTT*=})=; 8Q^; T{D0<}; Q,; T,;

- Accessor Function:

A(D!x-{D~}`)=;

- Incrementing Function (Pointer):

X0=; I(XX1+=)=;

- Decrementing Function (Pointer):

E(XX1-=)=;

- Altering Functions (Array):

B(XA^XA^1+=)=; C(XA^XA^1-=)=;

By these definitions, reduction is as follows:

Brainfuck @! > @I^; < @E^; + @B^; - @C^; [] XA^[]; . $XA^<; , &XA^>;

Without spaces or comments:

D@=;T2=;Q(x{TTT*=})=;8Q^;T{D0<};Q,;T,;A(D!x-{D~}`)=;X0=;I(XX1+=)=;E(XX1-=)=;B(XA^XA^1+=)=;C(XA^XA^1-=)=;

### Hello_World!

Classic program.

A@=;AH'<;Ae'<;Al'<;Al'<;Ao'<;A_'<;AW'<;Ao'<;Ar'<;Al'<;Ad'<;A!'<;A!{A$>};

### Quine

A popular problem.

(Written by User:CodingBat)

S@=;S$'<;SS'<;S''<;S<'<;S;'<;S$'<;S@'<;S''<;S<'<;S;'<;S$'<;S''<;S<'<;S;'<;S$'<;S;'<;S''<;S<'<;S;'<;SS'<;S!'<;S{'<;S$'<;SS'<;S''<;S<'<;S;'<;S$'<;SS'<;S`'<;S<'<;S;'<;S$'<;S''<;S''<;S<'<;S;'<;S$'<;S<'<;S''<;S<'<;S;'<;S$'<;S;'<;S''<;S<'<;S;'<;SS'<;S~'<;S;'<;S}'<;S;'<;SS'<;S!'<;S{'<;S$'<;SS'<;S`'<;S<'<;S;'<;S}'<;S;'<;$S'<;$@'<;$'<;$;'<;S!{$S'<;$S`<;$''<;$<'<;$;'<;S~;};S!{$S`<;};

### Examples With %

Here is an interesting example using %. The instruction queue will be show for clarity.

:% = <({TY'=;},{%~;},{TN'=;},{T$>;})<: TY'=; :% = <({%~;},{TN'=;},{T$>;})<: %~; :% = <({T$>;},{TN'=;})<: TN'=; :% = <({TN'=;})<: T$>;

A puzzle for the reader: What is the value of T at the end of this program?

A(x[%~])=; 3A^; TY'=; 2A^; TN'=; 5A^; %T>;