Written in JavaScript, sign-lang is a Brainfuck inspired programming language, designed to be another fancy way to say "Hello, world."

• Installation
• Code Execution
  • With CLI
  • JavaScript
• Language Concept
• Language Syntax
  • Signs
    • Sign Groups
    • Barriers
  • Output
  • Labels
  • Duplicator
  • Jumps
    • Conditional Jumps
  • Reserved Variable

npm install sign-lang

You can execute the source file using the CLI tool:

npx sign-lang <path/to/file.sign> [-i <input>]

Or, you can also use the JavaScript API:

import SignLang from "sign-lang";

const src = ">> [in]";
const input = "E";

const intepreter = new SignLang().setInput(input).intepret(src);

console.log(intepreter);

You can also log the value each time the intepreter output the value:

new SignLang({
  onexecute(value) {
    console.log(value);
  }
}).setInput(input)
  .intepret(src);

Inside of the sign-lang code, you will find lines of Instruction, which can be separated into two parts: the Instructor and the Expression. The intepreter will use Instruction Pointer to mark the line that will be processed. Once it's processed, the Expression will be parsed into a value first though Signs inside it. Then, the intepreter will check the Instructor to see what to do with the processed Expression value.

| an example of sign-lang code that prints numbers from 1 to 10

#str       |
#end       ----------
#str       {str}-
>>         {str}
v(str|end) --
>          == ------
^(str!end) ----

| outputs "1,2,3,4,5,6,7,8,9,10"

Signs are the only way to define a value. When they are tailed (connected) to each other, a Sign Group is formed along with the Expression value being added by the sign's value.

There are four Signs available in sign-lang:

• . = 0.1
• _ = 0.5
• - = 1
• = = 25

>> ---. | 3.1  (1 + 1 + 1 + 0.1)
>> ===_ | 75.5 (25 + 25 + 25 + 0.5)

Signs Groups are separated with a space ( ). When there are more than one Sign Groups in an Expression, they will attack each other, subtracting the Expression value.

>> == ----- | 45 ((25 + 25) + (1 + 1 + 1 + 1 + 1))
>> - -      | 0  (1 - 1)

A pipe character (|) is used as a Barrier. When an intepreter encounters it, it will immediately move to the next Instruction and ignore all types of Sign behind it.

>> =--|--      | 27 (25 + 1 + 1)
>> = --- | --  | 22 (25 - (1 + 1 + 1))
>> |           | 0

sign-lang uses Greater Sign (>) to output the value.

• If there's only one (>), it will convert the Expression value into as ASCII character before printing.
• If there are two (>>), it will simply print that value as a number.

>  === ---  | H
>> === ---  | 72

Labels or Variables can be used to store an Expression value after finishing processing by using the tag (#) followed by the label name.

NOTE: Labels can't contain spaces ( ), as it will mix with a normal space that is used to separate Instructor and Expression.

#var === --- | var now contains 72

And if you want to call the Label, you can use braces ({, }) with the variable name inside. You can also mutate the Label value any time.

| .
| .
| .
>>   {var}    | 72
>>   {var} -- | 70

#var {var}--- | var now contains 75 instead of 72
>>   {var}    | 75

Duplicator uses asterisk sign (*) for a multiplication towards a Label. It will take the value of the Label name after it and multiply it with the Expression value.

#a =-   | a is 26
*a ---- | (26 * 4)
>> {a}  | prints 104

Jumps, similar to goto statement in other languages, is used to move the Instruction Pointer by the Expression value from its current line:

• ^ will move the Instruction Pointer to the upper line.
• v will move the Instruction Pointer to the under line.

DANGER: Be careful when using these; you may experience an infinite loop from them.

#a ==== ---
#n =--(----)--
> {a}
v ---   | line 1 skipped (skip by 3 lines starting from this line)
> {n}   | line 2 skipped
> {n}-  | line 3 skipped
> {n}   | Instruction Pointer will move to this line and execute it

| outputs "an"

Or, you can simply count the line up or down.

#a ==== ---
#n =--(----)--
> {a}
v ---   | start counting
> {n}   | count 1
> {n}-  | count 2
> {n}   | count 3 (Instruction Pointer will move to this line and execute it)

| outputs "an"

When Jumps syntaxes are tailed by a parenthesis of two variables separated by | or ! ((a|b) or (a!b)), they will turn into a Conditional Jump:

• If variables are splitted with |, the jump will occur if those variables are equal to each other.
• If variables are splitted with !, the jump will occur if those variables are not equal to each other.

#str       |
#end       ----------
#str       {str}-
>>         {str}
v(str|end) --         | will jump if 'str' is equal with 'end'
>          == ------
^(str!end) ----       | will jump if 'str' is "not" equal with 'end'

| outputs "1,2,3,4,5,6,7,8,9,10"

You can access to the input and other special variable provided by the language by writing their name with brackets ([, ])

• [in] is used to access each character of the input by the call time. If the call time is out of input's length then NUL character will be printed.
• [nl] is for new-line character (\n)
• [sp] is for space character ( )

| If input is "abc"
> [in]
> == ------
> [nl]
> [in]
> == ------
> [nl]
> [in]
> == ------
> [nl]
> [in]

| (prints ▼)
| a,
| b,
| c,
| ,
|