Better Debugging == bedbug
by Tim Kay
timkay@not.com
Working with numbers, debug output often looks cluttered due to too many decimal places. Bedbug enhances JavaScript template literals ("backtick" strings) to improve readability.
Instead of this output:
console.log(`The answer is a=${9.12345678} 1/3=${1/3} Math.PI=${Math.PI}`);
> The answer is a=9.12345678 1/3=0.3333333333333333 Math.PI=3.141592653589793
add the letter f, and you get this output:
console.log(f`The answer is a=${9.12345678} 1/3=${1/3} Math.PI=${Math.PI}`);
> The answer is a=9.123 1/3=0.333 Math.PI=3.142
You can also abbreviate. Instead of x=${x}, simply use =x:
console.log(f`The answer is a=${9.12345678} =1/3 =fred =Math.PI`);
> The answer is a=9.123 1/3=0.333 fred=4.197 Math.PI=3.142
Bedbug provides "tag" functions that modify how template literals work. Import the f tag like this:
import {f} from '//bedbug.timkay.com/bedbug.js';
console.log(f`The answer is a=${9.12345678} =Math.PI`);
> The answer is a=9.123 Math.PI=3.142
Using the builtin f tag, the =x syntax only works with global variables. To access local variables using the =x syntax, you need to add to the top of each scope:
const f = bedbug.g(x=>eval(x));
This version of f works with =x syntax for both global and local variables.
Unfortunately, you need to include it in every scope where local variables need to be displayed. This way, no need to import f, so import this way instead:
import bedbug from '//bedbug.timkay.com/bedbug.js';
To set display precision:
bedbug.precision(1e-4);
Examples:
let c = 3.1415;
let abc = 8.1234;
let u;
let n = null;
let a = [1, 2, 'tim', 0, u, n];
let o = {'tim': Math.PI, 'bob': 'mary', [Math.PI]: 'PI'};
let s = 'Hello, world!!';
f`c=${c} b=${b} =s =abc =b` ➔ c=3.142 b=99.123 s=Hello, world!! abc=8.123 b=99.123
f`=u =n =a` ➔ u=undefined n=null a=[1, 2, tim, 0, undefined, null]
f`=o =f` ➔ o={3.141592653589793: PI, bob: mary, tim: 3.142} f=(s, ...v) => fe(e, s, v)
f`pi found here... =Math.PI` ➔ pi found here... Math.PI=3.142
f`=o` ➔ o={3.141592653589793: PI, bob: mary, tim: 3.142}