[ruby/irb] Add OMIT_ON_ASSIGNMENT

Omit the results evaluated at assignment if they are too long.

The behavior of ECHO_ON_ASSIGNMENT being on by default is hard to understand,
so I change it to off by default. Instead, we turn OMIT_ON_ASSIGNMENT on by
default. The result is displayed on assignment, but it will always be short
and within one line of the screen.

https://github.com/ruby/irb/commit/c5ea79d5ce

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/irb/input-method.rb b/lib/irb/input-method.rb
index 7cb211354b..6e87488753 100644
--- a/lib/irb/input-method.rb
+++ b/lib/irb/input-method.rb
@@ -12,6 +12,7 @@
 require_relative 'src_encoding'
 require_relative 'magic-file'
 require_relative 'completion'
+require 'io/console'
 require 'reline'
 
 module IRB
@@ -36,6 +37,14 @@ module IRB
     end
     public :gets
 
+    def winsize
+      if instance_variable_defined?(:@stdout)
+        @stdout.winsize
+      else
+        [24, 80]
+      end
+    end
+
     # Whether this input method is still readable when there is no more data to
     # read.
     #