[ruby/irb] Add doc about "echo on assignment"

https://github.com/ruby/irb/commit/5af637b3c1

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index 6dc5d7f0fd..09fd840bd3 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -274,6 +274,18 @@ module IRB
     #     IRB.CurrentContext.echo_on_assignment = true
     #     a = "omg" * 10
     #     #=> omgomgomgomgomgomgomgomgomgomg
+    #
+    # To set the behaviour of showing on assignment in irb:
+    #
+    #     IRB.conf[:ECHO_ON_ASSIGNMENT] = :truncate or true or false
+    #
+    # or
+    #
+    #     irb_context.echo_on_assignment = :truncate or true or false
+    #
+    # or
+    #
+    #     IRB.CurrentContext.echo_on_assignment = :truncate or true or false
     attr_accessor :echo_on_assignment
     # Whether a newline is put before multiline output.
     #