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/**
* This is the common logic for both the Node.js and web browser
* implementations of `debug()`.
*
* Expose `debug()` as the module.
*/
exports = module.exports = debug;
exports.coerce = coerce;
exports.disable = disable;
exports.enable = enable;
exports.enabled = enabled;
exports.humanize = require('ms');
/**
* The currently active debug mode names, and names to skip.
*/
exports.names = [];
exports.skips = [];
/**
* Map of special "%n" handling functions, for the debug "format" argument.
*
* Valid key names are a single, lowercased letter, i.e. "n".
*/
exports.formatters = {};
/**
* Previously assigned color.
*/
var prevColor = 0;
/**
* Previous log timestamp.
*/
var prevTime;
/**
* Select a color.
*
* @return {Number}
* @api private
*/
function selectColor() {
return exports.colors[prevColor++ % exports.colors.length];
}
/**
* Create a debugger with the given `namespace`.
*
* @param {String} namespace
* @return {Function}
* @api public
*/
function debug(namespace) {
// define the `disabled` version
function disabled() {
}
disabled.enabled = false;
// define the `enabled` version
function enabled() {
var self = enabled;
// set `diff` timestamp
var curr = +new Date();
var ms = curr - (prevTime || curr);
self.diff = ms;
self.prev = prevTime;
self.curr = curr;
prevTime = curr;
// add the `color` if not set
if (null == self.useColors) self.useColors = exports.useColors();
if (null == self.color && self.useColors) self.color = selectColor();
var args = Array.prototype.slice.call(arguments);
args[0] = exports.coerce(args[0]);
if ('string' !== typeof args[0]) {
// anything else let's inspect with %o
args = ['%o'].concat(args);
}
// apply any `formatters` transformations
var index = 0;
args[0] = args[0].replace(/%([a-z%])/g, function(match, format) {
// if we encounter an escaped % then don't increase the array index
if (match === '%%') return match;
index++;
var formatter = exports.formatters[format];
if ('function' === typeof formatter) {
var val = args[index];
match = formatter.call(self, val);
// now we need to remove `args[index]` since it's inlined in the `format`
args.splice(index, 1);
index--;
}
return match;
});
if ('function' === typeof exports.formatArgs) {
args = exports.formatArgs.apply(self, args);
}
var logFn = enabled.log || exports.log || console.log.bind(console);
logFn.apply(self, args);
}
enabled.enabled = true;
var fn = exports.enabled(namespace) ? enabled : disabled;
fn.namespace = namespace;
return fn;
}
/**
* Enables a debug mode by namespaces. This can include modes
* separated by a colon and wildcards.
*
* @param {String} namespaces
* @api public
*/
function enable(namespaces) {
exports.save(namespaces);
var split = (namespaces || '').split(/[\s,]+/);
var len = split.length;
for (var i = 0; i < len; i++) {
if (!split[i]) continue; // ignore empty strings
namespaces = split[i].replace(/\*/g, '.*?');
if (namespaces[0] === '-') {
exports.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
} else {
exports.names.push(new RegExp('^' + namespaces + '$'));
}
}
}
/**
* Disable debug output.
*
* @api public
*/
function disable() {
exports.enable('');
}
/**
* Returns true if the given mode name is enabled, false otherwise.
*
* @param {String} name
* @return {Boolean}
* @api public
*/
function enabled(name) {
var i, len;
for (i = 0, len = exports.skips.length; i < len; i++) {
if (exports.skips[i].test(name)) {
return false;
}
}
for (i = 0, len = exports.names.length; i < len; i++) {
if (exports.names[i].test(name)) {
return true;
}
}
return false;
}
/**
* Coerce `val`.
*
* @param {Mixed} val
* @return {Mixed}
* @api private
*/
function coerce(val) {
if (val instanceof Error) return val.stack || val.message;
return val;
}