summaryrefslogtreecommitdiff
path: root/enumerator.c
diff options
context:
space:
mode:
authorzverok <zverok.offline@gmail.com>2019-10-24 19:35:36 +0300
committerNobuyoshi Nakada <nobu@ruby-lang.org>2019-10-26 14:58:08 +0900
commitbddb31bb37f878cf171f89ac54f7e43d7d59c444 (patch)
treea332274fe4ac60ae0f8a60331769cf78ca3d8805 /enumerator.c
parentcf9344131c3d0f5993c6d999c427a4c656df30a2 (diff)
downloadruby-bddb31bb37f878cf171f89ac54f7e43d7d59c444.tar.gz
Documentation improvements for Ruby core
* Top-level `return`; * Documentation for comments syntax; * `rescue` inside blocks; * Enhance `Object#to_enum` docs; * Make `chomp:` option more obvious for `String#each_line` and `#lines`; * Enhance `Proc#>>` and `#<<` docs; * Enhance `Processs` class docs.
Diffstat (limited to 'enumerator.c')
-rw-r--r--enumerator.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/enumerator.c b/enumerator.c
index 18d06bb3e9..eee3a34e6b 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -295,7 +295,8 @@ proc_entry_ptr(VALUE proc_entry)
* obj.enum_for(method = :each, *args){|*args| block} -> enum
*
* Creates a new Enumerator which will enumerate by calling +method+ on
- * +obj+, passing +args+ if any.
+ * +obj+, passing +args+ if any. What was _yielded_ by method becomes
+ * values of enumerator.
*
* If a block is given, it will be used to calculate the size of
* the enumerator without the need to iterate it (see Enumerator#size).
@@ -314,6 +315,11 @@ proc_entry_ptr(VALUE proc_entry)
* a = [1, 2, 3]
* some_method(a.to_enum)
*
+ * # String#split in block form is more memory-effective:
+ * very_large_string.to_enum(:split, "|") { |chunk| return chunk if chunk.include?('DATE') }
+ * # This could be rewritten more idiomatically with to_enum:
+ * very_large_string.to_enum(:split, "|").lazy.grep(/DATE/).first
+ *
* It is typical to call to_enum when defining methods for
* a generic Enumerable, in case no block is passed.
*