// http://www.bagley.org/~doug/shootout/index2.shtml / ackermann ack:{:[~x;y+1;~y;_f[x-1;1];_f[x-1;_f[x;y-1]]]} / array access / count lines/words/chars / echo client/server / exception mechanisms / fibonacci numbers fib:{x(1+\)/1 1} / hash (associative array access) / hashes II / heapsort / hello world / list operations / matrix multiplication / method calls / nested loops / object instantiation / producer/consumer threads / random number generator / regular expression matching / reverse a file / sieve of eratosthenes sieve:{(x#1){x[y*!-_-(#x)%y]:0;x}/y} primes:{n]:[n<4;,2;r,1_&sieve[n]r:_f[sieve]@-_-_sqrt n]} / spell checker / statistical moments / string concatenation / sum a column of integers / word frequency count