File 0557-erl_bifs-Add-a-note-to-the-comment-for-is_pure-3.patch of Package erlang
From 02de9d7de92298e807a0eef4816b36eab825e63a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org> Date: Wed, 20 Feb 2019 14:43:41 +0100 Subject: [PATCH 6/6] erl_bifs: Add a note to the comment for is_pure/3 --- lib/compiler/src/erl_bifs.erl | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/lib/compiler/src/erl_bifs.erl b/lib/compiler/src/erl_bifs.erl index d925decce6..94a5dfe012 100644 --- a/lib/compiler/src/erl_bifs.erl +++ b/lib/compiler/src/erl_bifs.erl @@ -32,6 +32,22 @@ %% Returns `true' if the function `Module:Name/Arity' does not %% affect the state, nor depend on the state, although its %% evaluation is not guaranteed to complete normally for all input. +%% +%% NOTE: There is no need to include every new pure BIF +%% here. Including it here means that the value of the function +%% will be evaluated at compile-time if the arguments are +%% constant. If that optimization is not useful/desired, there is +%% no need to include the new BIF here. +%% +%% Functions whose return value could conceivably change in a +%% future version of the runtime system must NOT be included here. +%% +%% Here are some example of functions that should not be +%% included: `term_to_binary/1', hashing functions, non-trivial +%% encode/decode functions. +%% +%% When unsure whether a new BIF should be included here, the +%% conservative safe choice is NOT to include it. -spec is_pure(atom(), atom(), arity()) -> boolean(). -- 2.16.4
