README

Panda is a new Smalltalk implementation, written from scratch in C99.

Implemented features:
* All Smalltalk-80 syntax supported.
* Fast bytecode interpreter (optionally uses gcc's computed goto)
* Mark-Compact garbage collector
* A small class library, with language core, data structures, and streams
* Basic support for reading code from command line

Next on the TODO:
* Image support
* Interactive command line client and better script file support

Building
========

$ ./configure && make

Panda isn't installable right now. The `panda' executable runs in the
directory in which it was built ("src/"), and expects the kernel library files
to be in "../st".

Usage
=====
 
The main executable `panda', reads Smalltalk statements from stdin, interprets
them and outputs the result of the last statement. Variables can be declared
in the usual Smalltalk way.

Examples
========

Here are some short examples. Make sure to browse through the class library in "st/" 
to see all the implemented classes.

1. Sort a constant array of SmallIntegers

   $ echo "#(3 7 5 7 12 1) sort" | ./panda

2. Bignum arithmetic

   $ echo "1000000000000000000000000 + 1" | ./panda

3. Data Structures: Put a pair #key -> 'foo' into a dictionary and attempt retrieval  

   echo "|map| 
         map := Dictionary new. 
         map at: #key put: 'foo'.
         map at: #key." | ./panda

4. Fun with blocks: Use block to select elements of array which are greater than 5

   $ echo "#(3 7 5 7 12 1) select: [ :x | x > 5 ]" | ./panda


5. Errors: Panda prints a useful traceback if there is an runtime error

   $ echo "#(3 7 5 7 12 1) reverse" | ./panda
    An error occurred during program execution
    message: reverse

    Traceback:
    Array(Object)>>error:
    Array(Object)>>doesNotUnderstand:
    UndefinedObject>>doIt[]
    UndefinedObject>>doIt
    System>>startupSystem