# forth.jl
A hobby implementation of a FORTH-like system atop the Julia scientific
-computing language. It will never be useful for any purpose besides, perhaps,
-pedagogical - although I wouldn't advise trying to learn forth by using this
-code directly. A better approach is to combine reading something like Leo Brodie's
-book Starting Forth with implementing your own forth.
-
-To a large degree this project is simply a port of the literate programming
-project JonesForth from x86 assembly + forth to julia + forth, although the
-mapping is in a few places non-trivial due to the fact that julia is a high
-level language. A huge proportion (say 80%) of the library code in src/lib.4th
-is directly copied from JonesForth. I've added some additional core definitions
-and modified some of the others to be a little bit closer to the behaviour of
-ANS forth (or at least FORTH 83).
+computing language. It will almost certainly never be useful for any purpose
+besides that which it has already fulfilled: forcing me to think quite
+carefully about how forth works.
+
+This package owes a massive debt to the existence of the literate programming
+project [JonesForth] (https://rwmj.wordpress.com/2010/08/07/jonesforth-git-repository/),
+which was an amazing read. To a large degree my package is simply a port of
+that project from x86 assembly + forth to julia + forth, although the mapping
+is in a few places non-trivial due to the fact that julia is a high level
+language. A huge proportion (say 80%) of the library code in src/lib.4th is
+directly copied from JonesForth. (The fact that it was possible to reuse this
+code was satisfying in its own right!) I've added some additional core
+definitions and modified some of the others to be a little bit closer to the
+behaviour of ANS forth (or at least FORTH 83).
There's quite a lot to say about the implementation, especially due to its
high-level grounding, but that will have to wait for another time.
The first thing the interpreter will do is compile the core definitions in
the library file. Once this is complete you can start entering forth commands:
- : star 42 emit ;
- ok
- star
- * ok
-
-Notice that unlike other forths, forth.jl echos a newline after reading each
-line of standard input. This is an unfortunate side-effect of the way that
-I've implemented the primitive word KEY. Hopefully I'll be able to fix this
-in future.
+ : star 42 emit ; ok
+ star * ok
There's an example Mandelbrot Set drawing program included in the examples
-directory. To run it, you'll have to locate this directory on your system
-(its location depends on what OS you happen to be using). Once found, use
-the "INCLUDE" word to compile its definitions. For example, on my system
-I can run the example in this way:
+directory. To run it, you'll have to locate this directory on your system (its
+location depends on what OS you happen to be using and how julia is installed).
+Once found, use the INCLUDE word to compile its definitions. For example, on
+my system I can run the example in this way:
include /home/tim/.julia/v0.4/forth/examples/mandelbrot.4th
Enter 'mandel' to draw the Mandelbrot Set. ok
**
ok
+To exit, enter ^D on a blank line or use the `bye` word.
+
## License
This package is free software and is distributed under version 3.0 of the GNU