InfoQ is proud to present a comprehensive discussion of Ruby's various eval methods. This exclusive article is full of rich code examples, written by Domain-Specific Languages master Jay Fields, who after coining the term
Business Natural Langages last year, has gone ahead to widespread recognition for his pioneering work in enterprise usage of Ruby and Rails.
In the article, Jay teaches you the capabilities and differences between
class_eval,
instance_eval and plain
eval. His explanation provides insight into how the evaluation methods of Ruby provide very good options for creating concise, readable code.
Read
Evaluation Options in Ruby
Community comments
error
by haoxiang zhang,
Re: error
by haoxiang zhang,
error
by haoxiang zhang,
Your message is awaiting moderation. Thank you for participating in the discussion.
Select[:column1, :column2].from[:table1, :table2].where do
equal table1.id, table2.table1_id
end
it is should be use {} instend of do ... end
because of do...end will be send to Select method , not where.
Re: error
by haoxiang zhang,
Your message is awaiting moderation. Thank you for participating in the discussion.
sorry, it is my fault.