RETRO FORTH

# Syntax

RETRO code consists of a series of whitespace delimited tokens. Each of these can have an optional prefix telling RETRO how to treat the token. If the token lacks a valid prefix, it will be treated as a word name.

So:

[prefix][token]

Prefixes are single character modifiers. They are similar to colors in ColorForth, but are handled via words in the `prefix:` namespace.

The major prefixes are:

@ Fetch from variable
! Store into variable
& Pointer to named item
# Numbers
$ ASCII characters
' Strings
( Comments
: Define a word

Example:

~~~
(This_is_a_comment)
~~~

Define some words:

~~~
:hello  (-)
  'Hello_World! puts nl ;

:n:square  (n-m)
  dup * ;
~~~

And then use them:

~~~
hello
#33 n:square
~~~

Numbers must be prefixed with a # for RETRO to recognize them:

~~~
#2 putn sp
#3 putn sp
#4 putn sp
nl
~~~

A few more things...

~~~
$a (this_is_the_ASCII_'a')
~~~

Strings:

~~~
'Use_underscores_in_place_of_spaces_in_strings
puts nl
~~~

Strings also allow for formatted output:

~~~
#3 #1 #2 '%n_+_%n_=_%n\n s:format puts
~~~

Variables:

~~~
'Foo var
#100 !Foo
@Foo putn
~~~

Note that RETRO will only run code in a fenced block (starting and ending with ~~~). This allows for code and documentation to be intermixed easily.

The full glossary can be browsed:

http://forthworks.com:9999 or gopher://forthworks.com:9999