Usage of top-level calls

[Andarist]

Top level calls are hard to treeshake because tree-shakers/minifiers are often "afraid" of removing them because of potential side-effects of those calls.

Culprits:

d3-array/src/bisect.js

Line 4 in 36edab3

var ascendingBisect = bisector(ascending);

d3-array/src/ticks.js

Lines 1 to 3 in 36edab3

	var e10 = Math.sqrt(50),
	e5 = Math.sqrt(10),
	e2 = Math.sqrt(2);

Possible solution:
Add #__PURE__ annotations before those calls to reassure UglifyJS that those calls can be dropped if their results stay unused - either manually or with help of https://github.com/Andarist/babel-plugin-annotate-pure-calls

Intent to implement:
yes - would only have to know if you want to tackle this one

[mbostock]

I’ll tackle this when Rollup adds support for pure annotations rollup/rollup#1293.

[conartist6]

I just opened rollup/rollup#2429 against Rollup adding that functionality. Feel free to weigh in.