thaw-interpreter/README.md

Programming language interpreters, including LISP, Scheme, and Prolog.

# thaw-interpreter
Programming language interpreters, including LISP, Scheme, and Prolog.

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Much of the code in this library was based on or inspired by the book 'Programming Languages: An Interpreter-Based Approach', by Samuel N. Kamin, 1990, Addison Wesley, ISBN 0-201-06824-9.

## Building and Installing the App

Build and install the app via:

```console
$ npm run all
$ npm link
```

## Launching the App

Start an interpreter via the command:

```console
$ intrp [language-name]
```

... where [language-name] is one of:

- minimal
- chapter1
- lisp
- apl
- scheme
- sasl
- clu
- smalltalk
- prolog

## Session Example

```console
$ intrp scheme

This is the command line interface for thaw-interpreter

Starting the read-evaluate-print loop:

> (+ 2 3)
5

> exit
Exiting...

$
```

## The Script Runner

The interpreter provides a limited facility for running scripts. Currently, it is capable of reducing Lambda calculus expressions.

Example: Addition of two Church numerals using pure Lambda calculus:

```console
$ ./run-script.js lcaug examples/scripts/lambda-calculus-augmented-syntax/test1.lca 

Expression as string: (+ 2 3) 

Parsed expression: λf.λx.((λf.λx.(f (f (f x))) f) ((λf.λx.(f (f x)) f) x))

Reduced expression: Integer 5
```

## License
[MIT](https://choosealicense.com/licenses/mit/)

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