diff options
| -rw-r--r-- | activesupport/lib/active_support/core_ext/object/blank.rb | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/blank.rb b/activesupport/lib/active_support/core_ext/object/blank.rb index 1b94dee6cc..d6bad98376 100644 --- a/activesupport/lib/active_support/core_ext/object/blank.rb +++ b/activesupport/lib/active_support/core_ext/object/blank.rb @@ -110,8 +110,12 @@ class String # # @return [true, false] def blank? - # Regex check is slow, only check non-empty strings. - # A string not blank if it contains a single non-space string. + # In practice, the majority of blank strings are empty. The predicate is + # about 3.5x faster than the regexp check so we first test empty?, and then + # fallback. Penalty for the rest of strings is marginal. + # + # Double negation in the second operand is also a performance tweak, it is + # faster than the positive \A[[:space:]]*\z due to lack of backtracking. empty? || !(/[[:^space:]]/ === self) end end |