HELP PRINTI                                     Robin Popplestone, Oct 93

    printi( STRING, LIST )

This  procedure  provides  a  way   of  printing  recursive  structures
with indentation.  It  will  print  the LIST  along
the  lines  of printf, except that  any %t occurring  in the STRING
will cause an  indenting counter, n_tab, to  be incremented  by 2.  Any
newline  characters printed  by printi will be followed by n_tab spaces.
Thus if you define printing functions for mutually recursive
data-structures (e.g. the abstract syntax of a computer language) using
printi,  with  %t  preceding any  %p  that  causes  recursive printing,
substructures will be neatly indented.

Notes:
    -printi- does NOT accept arguments in the alternative form
        printi( ITEM1, ITEM2, ..., ITEMn, STRING )
    as -printf- and -sprintf- do.


Example:

    : printi(
    :     'Data%t\n%p -- type\n%p -- name%t\n%p -- left \n%p -- right\n',
    :     [alpha beta gamma delta]
    : );

    Data
      alpha -- type
      beta -- name
        gamma -- left
        delta -- right