carld

(define (take-even lst)
  (letrec [(taker (lambda (lst-rem result)
                    ;(printf "~a ~a" lst-rem result)
                    (if (< (length lst-rem) 2)
                        result
                        (cons (car (cdr lst-rem)) (taker (cdr (cdr lst-rem)) result)))))]
                               
    (taker lst '())))

carld

; ISIN, e.g. US0378331005
(define Apple-ISIN "US0378331005")


; ISO6166 International Securities Identification Number (ISIN)
; ISO3166-2 plus National Securities Identifying Number (NSIN)
(match Apple-ISIN
  [(regexp #px"^([A-Z]{2})([0-9]{9})([0-9])$" (list _ country NSIN check))
   (list country NSIN check)])

carld

;;By Jhen Kung, [email protected]
;;app.rkt

#lang racket(require web-server/servlet
         web-server/servlet-env
         "router.rkt")

(serve/servlet mordor
               #:port 8080
               #:servlet-path "/"

carld

BEGIN {
  int visited[node_t];

  int visit(node_t n, edge_t e) {
    if (visited[n] == 0) {
      visited[n] = 1;

      for (e = fstin(n); e; e = nxtin(e)) {
        visit(e.tail, NULL);
      }

carld

/* LISP as a register machine. Any obj not in a reg or on the stack may be
 * collected at the end of eval (). */
#include <ctype.h>
#include <iso646.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef enum { no } truth;
enum type { nil_type, int_type, sym_type, cons_type, str_type };
typedef struct obj {

carld

#include<stdio.h>
int lookahead = -1;
void getchar_skipwhitespace() { while( (lookahead = getchar()) == ' ') ; }
int success() { getchar_skipwhitespace(); return 1; }
int failure() { return 0; }
int lparen() { return lookahead == '(' ? success() : failure(); }
int rparen() { return lookahead == ')' ? success() : failure(); }
int sym() { return lookahead >= 'a' && lookahead <= 'z' ? success() : failure(); }
int star( int (*a) (void) ) { return a() ? star(a) : 1; }
int main(int argc, char *argv[]) {

carld

run Proc.new { |env|
  ['200', {'Content-Type' => 'text/html'}, [env.to_s]]
}

carld

require 'rack'

app = Proc.new do |env|
  ['200', {'Content-Type' => 'text/html'}, [env.to_s]]
end

Rack::Handler::WEBrick.run app

carld

Run a ssh tunnel to a database via jump / bastion host

  ssh -v -L 9999:[database host]:5432 jumphost

  psql -h localhost -p 9999 -U [user] --password -d [database]

If you get:

carld

run = ->(a,v) { a.reduce(v){|x,y| break unless y.call(v); x } }                      
                                                                                     
run.call [                                                                           
  ->(v) { puts "Hello"; true },                                                      
  ->(v) { puts "World"; false },                                                     
  ->(v) { puts "!"; true }                                                           
], 1