Takes a function that gets called each time a field's value is retrieved. The following example returns the square of the field's value:

    (gui '(+Val +NumField) '((N) (* N N)) 10)
See also +Set, +Fmt, Formatting.
Links a form field to a variable.

    "Occupation" (gui 'job '(+Var +TextField) '*PrsJob 20)
This example links a text field to the variable *PrsJob. See also +E/R.
Like +Lock, view is a prefix class that disables a GUI component. However, +View can take a functional argument:

    (gui '(+Sgn +View +FixField) '(sum> (: home obj)) 2 12) ) )
This example is a snippet from the demo app included with the PicoLisp distribution, in ord.l. The code produces a disabled text field that displays the total order sum of the current order object. See also +Lock, +Upd, +Init.