Listok is a dialect of LISP

Useful as an embedded scripting language or as stand-alone app. It's a Scala-based and need in scala-library.jar to run.

features

• lisp-1
• lexical scoping
• tail-call optimization
• regex and pattern matching
• concurrency via threads and mailslots
• lazy sequences
• java interop

types

• nil, t
• int, float, bignum, ratio
• char, symbol, keyword, pair, byte, blob
• string, list, vector, hashmap, lazyseq
• hashtable
• stream
• regex
• thread, mailslot, process, connection
• function

special forms

• def, defconstant, defun, defstruct, setf,
• let, let*
• if, cond, do, and, or
• spawn, match
• collect
• assert

macro

• defmacro, macroexpand, gensym

built-in macros

• progn, dotimes, doseq, dowhile, loop, when, unless

built-in function

common

• eq, not, eval, apply, load, exit, error,

• break, trace, untrace

• curry, current-time, current-directory, json-parse

• display, format

• gensym, macroexpand

• to-str, to-char, to-int, to-float, to-number, to-list, to-vector

• atom, listp, null, sequencep, keywordp, numberp, symbolp, functionp

• stringp, vectorp, charp, streamp, regexp, bytep, blobp

• hashtablep, hashmapp threadp, mailslotp, structp, lazyseqp, pairp

number

• +, -, \/, *, <, <=, >, >=, =, \/=,
• incr, decr, rem, oddp, evenp, zerop, plusp, minusp
• min, max, abs, gcd, expt

sequences

• list, vector, string, range, pair

• length, head, first, last, tail rest

• cons, append, reverse, elt, set-elt, subseq,

• find, find-if, position, position-if, count, count-if,

• remove, remove-if, sort, take, drop,

• foreach, reduce, fold, map, flatmap, filter, partition,

• hashmap, hm-get, hm-add, hm-del

• hash-table, gethash, sethash, remhash, clrhash, maphash

• lazyseq, lazyseq-from, lazyseq-range, lazyseq-force

streams

• open, open-tcp-connection, open-http-connection, close
• read, read-byte, read-blob, read-char, read-text, read-line,
• print, write, write-byte, write-blob, write-char, write-string, write-line,
• terpri, newline,
• make-string-input-stream, make-string-output-stream,
• make-blob-input-stream, make-blob-output-stream,
• get-output-stream-string, get-output-stream-blob
• url-encode
• get-output-stream, get-input-stream
• open-stream-p, input-stream-p, output-stream-p

regex

• regex, regex-matches, regex-find, regex-find-all,
• regex-scan, regex-split, regex-replace

concurrent

• join, thread-wait-init, sleep
• mailslot, receive, send
• process, process-exit-value, process-wait,
• process-output-stream, process-input-stream, process-error-stream

sample code

pattern mathing and regex

(match s
  ((#/(\w+):(\d+)/ name id) 
    (display "name=%s id=%s\n" name id)))

thread and mailslot

(let ((x 1))
  (spawn worker ((x) (m (mailslot)))
      (send m (+ 1 x))))
(first (receive)) ; 2

tco

(defun evenp (n)
  (declare :tco)
  (if (eq n 0)
    t
    (oddp (- n 1))))

(defun oddp (n)
  (declare :tco)
  (if (eq n 0)
    nil
    (evenp (- n 1))))

(evenp 10002)

lazyseq

(defun sieve (s)
  (lazyseq (head s)
    (lambda (n)
      (sieve
        (filter
          (lambda (x) (/= 0 (rem x n)))
          (tail s))))))

(def primes (sieve (lazyseq-from 2)))  
(to-list (take primes 10))

collect

(def s (open (string (current-directory) "/src/test/resources/test.file" )))
(assert s)
(print (collect (dowhile (<< (read-line s)))))
(close s)

interop

(interop "java.io.File" 'make-file :constructor)
(interop "java.io.File.getAbsolutePath" 'file/path)
(file/path (make-file "."))

limitation

• in argument lists no &key or &options but only &rest parameter
• in macro definition use backquote instead of quote

planned in nearest future

• unwind-protect form and with-open macro

Build instructions

Listok uses sbt to build.
Get sbt at http://code.google.com/p/simple-build-tool/

To build:

cd listok
sbt update test package

To run REPL:

cd examples
./listok

To run examples:

cd examples
./queens.lok all
./gtranslate.lok en ru hello
./digest.lok digest.lok sha
./test.lok 256
./traffic.lok 100