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Experimental fork of, primarily for keyword args and generic functions
Arc Scheme Perl
Latest commit e347973 @akkartik stop pretending that this is production-ready
blurb on github used to be: My curated set of patches atop
now it's: Experimental fork of, primarily for keyword args and generic functions


An experimental and incompatible fork of the Arc programming language (

*Important*: If you are running a HN-like site, using this fork will mess up
your data. Talk to me first, and be sure to make a backup.

- Features so far
'$' for escaping to scheme for making scheme extensible from arc
Dynamic scope:

Extensible coerce (rntz;
Macros can be defined in any order.

All functions are generic and can be extended for new conditions
using 'defextend'.
  (Previous discussions:,,

pervasive keyword args. If a function f has params (a b c), (f :c 3 1 2) <=> (f 1 2 3), etc.
BUT this assumes no keyword syms in data:
  arc> (iso :x :x)  # won't work because x is a param of iso

new arglist syntax:
  arc> (def foo (a ? b 34) (list a b))
  arc> (foo 3)
  (3 34)

optional params and keyword args can't be combined with destructuring.

transparent persistence using 'persisted', which can be extended for new
datatypes by supporting the generics 'serialize' and 'unserialize'.

  parse IP from X-Forwarded-For
  access static subdirectories
  more mime-types, more html attributes, more useful logging
  correctly sends crlf-terminated lines

  readline handles empty lines:,
  downcase/upcase on nil return nil:
  each over tables returns nil

Case can work on lists and other compounds

- Incompatibilities and gotchas
0. temload and temstore are subtly different. If you've been using news.arc
on your own site, make a backup before switching.
1. nil == (); type.nil == nil.
2. Optional args have a new syntax. (a (o b) (o c 3)) => (a ? b nil c 3)
3. some and keep don't testify.
4. Always handle null values when defining a generic
5. srv no longer calls setuid. Run it behind apache or nginx, never as root.
6. thread and new-thread require docstrings, like in autosave-thread in state.arc.
7. case no longer autoquotes:
8. List operations treat non-lists as degenerate dotted lists by default.
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