# turingAutomaton #

a toy programming language for creating turing machines

## description ##

`turingAutomaton` is a programming language created to test the Racket ecosystem. it features custom syntax and is able to run single tape turing machines.

## installation ##

```
git clone https://git.lain.church/tA/turingAutomaton
cd turingAutomaton
raco pkg install
```

## syntax ##

all files must begin with a

```
#lang turingAutomaton
```

followed by a definition of;

```
@ beginningState
% blankSymbol
! acceptingState
```

(currently the accepting state is unimplemented)

`states` are defined using the following syntax;

```
: stateName
currentSymbol ~ newSymbol > newState
currentSymbol ~ newSymbol < newState
```

where `<` and `>` denote moving the tape left and right, respectively

comments are allowed:

```
; either on their own line
@ first ; or at the end of a line
```

## sample program ##

this machine will double a number passed to it

```
#lang turingAutomaton

; this is a comment!

@ first
% e
! F

: first
a ~ b > second
c ~ c > fourth

: second
a ~ a > second
c ~ c > second
e ~ c < third

: third
a ~ a < third
b ~ b > first
c ~ c < third

: fourth
c ~ c > fourth
e ~ e < fifth

: fifth
b ~ a < fifth
c ~ a < fifth
e ~ e > F
```

## caveats ##

currently very unfinished.

all input is a single tape defined with `aaaaa` for now.

there is no error checking until I learn how to do that.

might get slow for very large tapes as the tape uses linked lists to operate.

## thanks ##

mutce ckire to:
   * the racket team for creating an awesome language
   * Matthew Butterick for his book [Beautiful Racket](https://beautifulracket.com/) and the libraries within

## author ##

`fi'e la ti'ei`