All Ruby programmers regularly encounter the mystical error “syntax error, unexpected $end, expecting keyword_end.” We know what it means: we left off an end somewhere in the code. As Ruby compiled our source, it keeps track of nesting, and when it reached the end of file ($end), it was expecting to see one more end keyword, and none was there.
So, we trundle back through the source, and after a while discover we’d deleted just one too many lines during that last edit.
Ruby 1.9 makes that easier. For example, here’s a source file:
class Example def meth1 if Time.now.hours > 12 puts “Afternoon” end def meth2 # … end end
Run it through Ruby 1.9, and you’ll get the same old error message:
dave[RUBY3/Book 8:26:48] ruby t.rb t.rb:10: syntax error, unexpected $end, expecting keyword_end
But add the -w flag, and things get more interesting.
dave[RUBY3/Book 8:26:51] ruby -w t.rb t.rb:5: warning: mismatched indentations at ‘end’ with ‘if’ at 3 t.rb:9: warning: mismatched indentations at ‘end’ with ‘def’ at 2 t.rb:10: syntax error, unexpected $end, expecting keyword_end
It’s the small things in life…