blang/README.md

```
/*  _     _                       _
   | |   / |                     / /
   | |__| ||__ _ _ __   __ _    / /
   | '_ | |/  ' | '_ \ / _' |  / /
   | \_|| | ||  | | | | /_| | /_/
    \___/_____/___| |__,_  / _
                     |____/  */
```
# blang!
the bang language

Public domain. 2022 DTB.

## Glossary

### chart

The listing of the program currently running.
This can be modified during runtime.

### command

A character that indicates what the bang language executor should do next.

### hand

The general-purpose register.

### catch

To set the hand to a value.

### throw

To set a value to the contents of the hand.

## Reference

All operations are one character long.
When an unknown operation is executed the resulting behavior is undefined
(and maliciously so; for example, execution can stop or garbage can be written to the chart).

### `'!'`

No-op. Does nothing.
`' '`, `'\n'`, `'\r'`, `'\t'`, and `'\v'` are all also no-ops
\- keep this in mind when styling code that contains `'?'`!

### `';'`

Denotes a comment.
A comment starts with a semicolon (or `'#'`, for compatibility with shebangs)
and ends with a bang (`'!'`) or line feed (`'\n'`).

### `'%'`

Throws at the current location in the program listing to which chart points.

### `'^'`

Catches the constant `0`.

### `'&'` and `'*'`

`'&'` (ampersand) palms the chart. `'*'` (splat) throws the chart.

The following program rewrites itself during runtime using ampersand and splat:

```
^{?>!&++*<!%&++*<<%&+*<
%&+*<>%&+*<^%<!}

^;	zero out hand
{?>;	set return point; if hand is non-zero, print hand
!&++*;	palm the chart; add 2 to palm; splat the new chart
<!%;	write '!' to the new chart position
&++*;	palm the chart; add 2 to palm; splat the new chart
<<%;	write '<' to the new chart position
&+*;	advance the chart one space
<
%;	write '\n' to the new chart position
&+*;	advance the chart one space
<>%;	write '>' to the new chart position
&+*;	advance the chart one space
<^%;	write '^' to the new chart position
<!;	palm '!'
};	return
```

Right before the final `'}'`, the chart is the following:

```
^{!><
>^*<!%&++*<<%&+*<
%&+*<>%&+*<^%<!}

^;	zero out hand
{!>;	print hand
<
>;	palm `'\n'`; print hand
^*;	splat zero to chart

The rest of the program isn't executed.
```

## Examples

### true(1)
```
; initialize hand to 0
^

; set the chart pointer to 0 - this destroys the chart
; and the program exits with the value of the hand
* 
```

### Hello world:
```
; the <.> construct uses '<' to literally 'palm' the next value
; (store into hand), does so, and uses '>' to 'toss' (output hand's value)
<H><e><l><l><o><,>< ><w><o><r><l><d><!><
>^*
```