Something?Oops!

Something?Oops! is a simple esolang by User:A.

Syntax

The syntax is as follows:

Statement: "<identifier> <identifier>?Oops<variable>"
Identifier: A nonnegative integer or a variable
Variable: "!" or "?" or "." or ","

Commands

A statement of the form A B?OopsC stores A + B in C.

As opposed to traditional programming languages, the various effects, including value storage, input/output, and control flow, does not depend upon the choice among the available instructions, but upon utilized variables and whether they are applied in a reading or writing context.

Four variables exist, each of which distinguished by their identity and side effects:

Variable	Effect
?	Is a special variable in that reading from it produces input from the user rather than ?'s value, thus making ? effectively read-only as a variable. The user input is expected to be communicated in the form of a nonnegative integer number.
.	Produces output, and though it can be used as a normal variable, anything written to it is also output to the screen.
,	Is also special: it's the instruction counter. When reading, it returns the current instruction index. When writing, a jump (goto) to the specified instruction is exercised. The enumeration starts at one (1).
!	In fact, only ! is a “normal” variable at all.

Example

Truth-machine

? 2?Oops,
0 5?Oops,
0 1?Oops.
0 3?Oops,
0 0?Oops.

Counter

This short program prints the numbers 1, 2, and 3 by employment of the instruction counter.

0 ,?Oops.
0 ,?Oops.
0 ,?Oops.

Interpreter

• Common Lisp implementation of the Something?Oops! programming language.