add documentation for side_effects & [#@]__PURE__ (#1925)

2017-05-11 23:29:55 -05:00
parent daaefc17b9
commit 547f41beba
1 changed files with 5 additions and 0 deletions
--- a/README.md
+++ b/README.md
@@ -409,6 +409,11 @@ to set `true`; it's effectively a shortcut for `foo=true`).
 - `keep_infinity` -- default `false`. Pass `true` to prevent `Infinity` from
  being compressed into `1/0`, which may cause performance issues on Chrome.

+- `side_effects` -- default `false`. Pass `true` to potentially drop functions
+marked as "pure".  (A function is marked as "pure" via the comment annotation
+`/* @__PURE__ */` or `/* #__PURE__ */`)
+
+
 ### The `unsafe` option

 It enables some transformations that *might* break code logic in certain