File 1026-erlang-module-doc-fun_to_list-1.patch of Package erlang

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File 1026-erlang-module-doc-fun_to_list-1.patch of Package erlang

From 876b213b8f97cc5c5d101ddc5bbbd33ed7ab5ead Mon Sep 17 00:00:00 2001
From: Kjell Winblad <kjellwinblad@gmail.com>
Date: Thu, 3 Sep 2020 09:33:07 +0200
Subject: [PATCH 16/39] erlang module doc: fun_to_list/1

Describe what this function returns more precisely.
---
 erts/doc/src/erlang.xml       | 39 +++++++++++++++++++++++++++++++++--
 erts/preloaded/src/erlang.erl |  5 +++--
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 004ac3a1f6..35a9543023 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -2033,8 +2033,43 @@ true</pre>
 <name name="fun_to_list" arity="1"/>
 <fsummary>Text representation of a fun.</fsummary>
 <desc>
- Returns a string corresponding to the text
- representation of <c><anno>Fun</anno></c>.
+ <warning>
+ This function is not guaranteed to work as described here
+ when <c><anno>Fun</anno></c> was created while executing
+ uncompiled code (uncompiled escripts, the Erlang shell, and
+ other code executed by the <seealso
+ marker="stdlib:erl_eval"><c>erl_eval</c> module</seealso>).
+ </warning>
+ Returns <c><anno>String</anno></c> that represents the code
+ that created <c><anno>Fun</anno></c>.
+ <warning>
+ Generally, one can not use this function to check if two
+ funs are equal as this function does not take the fun's
+ environment into account. See <seealso
+ marker="#fun_info/1"><c>erlang:fun_info/1</c></seealso> for how
+ to get the environment of a fun.
+ </warning>
+ <note>
+ <c><anno>String</anno></c> has the following form, if
+ <c><anno>Fun</anno></c> was created by an expression of the
+ form <c>fun ModuleName:FuncName/Arity</c>:
+
+ <c>"fun ModuleName:FuncName/Arity"</c>,
+
+ and <c><anno>String</anno></c> has the following form, if
+ <c><anno>Fun</anno></c> was created by a <seealso
+ marker="system/reference_manual:expressions#fun-expressions">fun
+ expression</seealso>:
+
+ <c>"#Fun&lt;M.I.U>"</c>, where M, I and U correspond to
+ the values named <c>module</c>, <c>index</c> and <c>uniq</c>
+ in the result of <seealso
+ marker="#fun_info/1"><c>erlang:fun_info(Fun)</c></seealso>.
+
+ The output of <c>fun_to_list/1</c> can differ between
+ Erlang implementations and can change in future
+ versions.
+ </note>
 </desc>
 </func>
 
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 7b054b84b7..66695f784b 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -934,8 +934,9 @@ fun_info_mfa(_Fun) ->
 erlang:nif_error(undefined).
 
 %% fun_to_list/1
--spec erlang:fun_to_list(Fun) -> string() when
- Fun :: function().
+-spec erlang:fun_to_list(Fun) -> String when
+ Fun :: function(),
+ String :: string().
 fun_to_list(_Fun) ->
 erlang:nif_error(undefined).
 
-- 
2.26.2

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File 1026-erlang-module-doc-fun_to_list-1.patch of Package erlang

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