chmike

func dumpByteSlice(b []byte) {
	var a [16]byte
	n := (len(b) + 15) &^ 15
	for i := 0; i < n; i++ {
		if i%16 == 0 {
			fmt.Printf("%4d", i)
		}
		if i%8 == 0 {
			fmt.Print(" ")
		}

chmike

// NewRateLimiter returns a rate limiter function returning false 
// when the event must be rejected, and true when it must be accepted. 
// The rate is expressed in Hz (events/seconds). It simply ensures that
// the time interval between two accept satisfies the rate criteria. It
// is equivalent to the token bucket algorithm with a bucket size of one.
func NewRateLimiter(rate float64) func() bool {
	var stamp time.Time // time stamp of last accepted event
	return func() bool {
		now := time.Now()
		if now.Sub(stamp).Seconds() *rate < 1. {

chmike

// Please use the package https://github.com/chmike/domain as is it maintained up to date with tests. 

// checkDomain returns an error if the domain name is not valid.
// See https://tools.ietf.org/html/rfc1034#section-3.5 and
// https://tools.ietf.org/html/rfc1123#section-2.
func checkDomain(name string) error {
	switch {
	case len(name) == 0:
		return nil // an empty domain name will result in a cookie without a domain restriction
	case len(name) > 255:

chmike

package main

import (
	"image/color"
	"log"
	"os"
	"strings"

	"gioui.org/app"
	"gioui.org/f32"

chmike

package main

import (
	"fmt"
	"image"
	"image/color"
	"os"

	"gioui.org/app"
	"gioui.org/font/gofont"

chmike

Problems with Go's shorthand declaration :=

The shadow variable trap

The problem

It is best illustrated with the following Go code snippet.

var x int

chmike

// getlinefd reads a full line from fd into *lineptr. Initialize *lineptr to NULL and *n to 0.
// getlinefd will store the line into *lineptr which is is a buffer that will grow as needed.
// The buffer size is stored in *n. The line ends '\0' and with a '\n'when present.
// getlinefd returns the number of characters read, or -1 in case of error or if the end of file is reached.
ssize_t getlinefd(char **lineptr, size_t *n, int fd) {
    static char buf[10];
    static size_t len = 0;
    const size_t blen = sizeof(buf);

    if (lineptr == NULL || n == NULL) {

chmike

res, err := http.GET(...)
if res != nil {
    defer func() {
        _, err = io.Copy(ioutil.Discard, res.Body)
        res.Body.Close()
    }()
}
if err != nil {
    // . . . 
}

chmike

var (
	cnNameOid = asn1.ObjectIdentifier{2, 5, 4, 3}
	emailOid  = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 1}
	userIDOid = asn1.ObjectIdentifier{0, 9, 2342, 19200300, 100, 1, 1}
	dcNameOid = asn1.ObjectIdentifier{0, 9, 2342, 19200300, 100, 1, 25}
)

// RDNSToString returns the Relative Distinguish Name as a string.
func RDNSToString(rdns *pkix.RDNSequence) string {
	var buf strings.Builder

chmike

#include <sys/time.h>

// Return the current time as a double float in second units
double getTimeAsDouble()
{
    struct timeval t;
    ::gettimeofday( &t, NULL );
    return double(t.tv_sec) + double(t.tv_usec)/1000000.0; 
}