Method: Kernel#demo

Defined in:
lib/core/facets/kernel/demo.rb

#demo(out = $stdout, &block) ⇒ Object

For debugging and showing examples. Currently this takes an argument of a string in a block…

demo {%{ a = [1,2,3] }}
demo {%{ a.slice(1,2) }}
demo {%{ a.map { |x| x**3 } }}

produces …

a = [1,2,3]             #=>  [1, 2, 3]
a.slice(1,2)            #=>  [2, 3]
a.map { |x| x**3 }      #=>  [1, 8, 27]

NOTE: This method is not a common core extension and is not loaded automatically when using require 'facets'.

Uncommon:

  • require ‘facets/kernel/demo’



25
26
27
 
# File 'lib/core/facets/kernel/demo.rb', line 25

def demo(out=$stdout,&block)
  out << sprintf("%-25s#=>  %s\n", expr = block.call, eval(expr, block.binding).inspect)
end