A small class to convert a map of Booleans to Integer and vice versa with help of defined schema. The constructor of Bitmask expects names which created instance use for conversion. Use the module to solve the bitmask conversion problem robustly.
npm install wBitmaskBy using bitwise operations we can easily get needed bit(s) and set to or compare with value of our variable. For example, by using shift operators and bitwise AND we can get boolean value of our flag masked in a number and set it to our property in a map.
More about bitwise operations.
terminal
npm install wBitmask
`$3
git clone https://github.com/Wandalen/wBitmask
cd wBitmask
will .npm.install
node sample/trivial/Sample.s
Make sure you have utility
installed. To install willbe: npm i -g willbe@stable. Willbe is required to build of the module.$3
`
npm add 'wBitmask@stable'
is not required to use the module in your project as submodule.Usage
`javascriptlet _ = wTools;
/define array of possible names and bit values, that can vary/
var defaultFieldsArray =
[
{ hidden : false },
{ system : false },
{ terminal : true },
{ directory : false },
{ link : true },
];
/create new instance of wBitmask by passing options object with array( defaultFieldsArray ) to the constructor/
var bitmask = wBitmask
({
defaultFieldsArray : defaultFieldsArray
});
console.log( 'bitmask' )
console.log( bitmask.toStr() );
/*
bitmask
{
hidden : false,
system : false,
terminal : true,
directory : false,
link : true
}
*/
/define our boolean map/
var originalMap =
{
hidden : 1,
terminal : 0,
directory : 1,
}
console.log( 'originalMap :\n' + _.entity.exportString( originalMap ) );
/*originalMap :
{ hidden : 1, terminal : 0, directory : 1 }*/
/Convert boolean map into 32-bit number bitmask/
var word = bitmask.mapToWord( originalMap );
console.log( 'word : ' + word );
/word : 25/
/Convert 32-bit number bitmask into boolean map /
var restoredMap = bitmask.wordToMap( word );
console.log( 'restoredMap :\n' + _.entity.exportString( restoredMap ) );
/*restoredMap :
{
hidden : true,
system : false,
terminal : false,
directory : true,
link : true
}*/
``