W/ hints of Lisp, to taste.
There are just two kinds of function: unary and binary. To receive more
arguments one must take a list. Unary functions are applied with no whitespace,
binary functions are applied with whitespace. Macros are denoted by a $ and
simply consume expressions until a matching closing brace or a ;. Functions,
are an optional string of alphanumeric characters (or _) followed by a string
of punctuation characters, but other expressions (such as variables not ending
in punctuation) can be used as functions by appending a : (no whitespace).
Example:
print:"Hello, world!";
$def do_thing: a b
+ a b;
$def % fn a (
print:fn;
fn:a
);
% (-) do_thing: 1 2
Prints
Hello, world!
($fn a b {{builtin}})
and outputs -3
Features implemented:
- Opt-in memoisation: currently implemented in the runtime, but memoised functions can already be created without the runtime support - it's just super unergonomic without macros. See below.
- Pattern-matching: includes wildcards (
_) and deconstructing the rest of a list ([a b c ..rest]) just like [insert favourite ML dialect]. Also includes the ability to use predicates such as($fn do_thing:int?i + i 1). This is basically just so I can get parametric polymorphism without having to read a book on Hindley-Milner type systems. This currently can't be implemented in script-space macros - even if I implemented macros - like it is in lisp because it's used by the runtime for... - Function resolution based on patterns: so I really like being able to define
the same function with different guards or patterns in Haskell and dispatching
to different implementations based on value at runtime, but I quite like being
able to interpret my code line-by-line, so to allow that I implemented this
glorious hack where when looking for a function I will continuously step back
to earlier and earlier definitions until I reach one with a matching pattern.
This currently doesn't work when passing functions as arguments unless you do
some dirty hack like
map: ($fn a do_thing:a) [1 2 3]. I'll hopefully fix that in the future.
Features not yet implemented:
- Macros
- IO (you can print but that's it)
For more examples of code, check out test.pfx.