Create a parse tree from an array of terms representing an expression.

Parse the expression:

  my @e = qw(
  v_sub a_is
    v_array as v1 d_== v2
      a_then v3 d_plus v4
      a_else v5 d_== v6
        a_then v7 d_minus v8
        a_else
          v9 d_times b v10 d_+ v11 e_* v12 B)

to get:

     is
 sub          as
        array             then
                    ==                    else
                 v1    v2         plus                  then
                               v3      v4         ==                     else
                                               v5    v6         minus            times
                                                             v7       v8      v9                   bB
                                                                                           +
                                                                                       v10       *
                                                                                             v11   v12
END

For full documentation see: CPAN