With Statement :With obj

Formal Definition

:With is a control structure that may be used to simplify a series of references to an object or namespace. :With changes into the specified namespace for the duration of the control structure, and is terminated by :End[With]. obj is either the name of or a reference to a namespace. For example, you could update several properties of a Grid object F.G as follows:

       :With F.G
            Values←4 3⍴0
            RowTitles←'North' 'South' 'East' 'West'
            ColTitles←'Cakes' 'Buns' 'Biscuits'
       :EndWith

:With is analogous to ⎕CS in  the following senses:

  • The namespace argument to :With is interpreted relative to the current space.
  • With the exception of those with name class  9, local names in the containing defined function continue to be visible in the new space.
  • Global references from within the :With control structure are to names in the new space.
  • Exiting the defined function from within a :With control structure causes the space to revert to the one from which the function was called.

On leaving the :With control structure, execution reverts to the original namespace. Notice however that the interpreter does not detect branches (→) out of the control structure. :With control structures can be nested in the normal fashion: 

[1]   :With 'x'           ⍝ Change to #.x
[2]       :With 'y'       ⍝ Change to #.x.y
[3]           :With ⎕SE   ⍝ Change to ⎕SE
[4]               ...     ⍝ ... in ⎕SE
[5]           :EndWith    ⍝ Back to #.x.y
[6]       :EndWith        ⍝ Back to #.x
[7]   :EndWith            ⍝ Back to #