When working in TextMate, if you have a one or more lines of Ruby code that you would like to have the interpreter run, without the need for passing the entire file to the interpreter, this tip may be just what the doctor ordered.
For example, when debugging, often times it would be really handy to run a simple script at a specified location in your code to look at a value, call a method on an Object The key point here is that you can have as little as one line of Ruby processed by the interpreter and the return value will be inserted inline.
This easiest way to get the gist of this is to watch the screencast below:
If you want to insert the results of one or more lines of script, directly into your code, using # => markers is the way to go.
The music in the video is J.J. Cale and the song: Call Me the Breeze.
A longer clip of J.J. Cale jamming: