Chicken Scheme and malformed definitions

Question

Chicken Scheme 4.8.0.5

Greetings all,

Here's a snippet of a malformed definition of a list of lists. I say malformed because the variable name lies outside the leftmost parenthesis and there is no explicit define statement ie. (define techDisplays ((AG1 fillerIgnore....nil nil))

snippet.il

techDisplays(
;( LayerName            Purpose                  Packet                         Vis Sel C2C Drg Val )
;( ---------            -------                  ------                         --- --- --- --- --- )
( AG1                  fillerIgnore             AG1_fillerIgnore                t   t  nil  t  nil )
( AG2                  drawing                  AG2_drawing                     t   t  nil  t   t  )
( AG2                  fillerIgnore             AG2_fillerIgnore                t   t  nil  t  nil )
( AG2                  frame                    AG2_frame                       t   t  nil  t   t  )
( AG2                  frameOnly                AG2_frameOnly                   t   t  nil  t   t  )
( AG2                  frameOnlyHole            AG2_frameOnlyHole               t   t  nil  t   t  )
( y0               flight     y0_flight                 t   t   t   t   nil )
( y1               flight     y1_flight                 t   t   t   t   nil )
( y2               flight     y2_flight                 t   t   t   t   nil )
( y3               flight     y3_flight                 t   t   t   t   nil )
( y4               flight     y4_flight                 t   t   t   t   nil )
( y5               flight     y5_flight                 t   t   t   t   nil )
( y6               flight     y6_flight                 t   t   t   t   nil )
( y7               flight     y7_flight                 t   t   t   t   nil )
( y8               flight     y8_flight                 t   t   t   t   nil )
( y9               flight     y9_flight                 t   t   t   t   nil )
( border           boundary   border_boundary           t   nil t   t   nil )
( snap             grid       snap_grid                 t   nil t   nil nil )
) ;techDisplays

Problem: I need to get Scheme to recognise this as a valid top-level definition Further problem: Solution must be scalable as there's 100s more where this one came from that I must read in as well Constraint: I would very very much like NOT to have to write some parsing routine as it'd very likely turn out wrong what with all the parenthesis-counting , matching, and layering.

Any ideas, hints, constructive critisisms are all welcome.

TIA,

Still-learning Steve

Answer 1

Consider this,

; this is structured as your input with just a space after the first name
#;1> (define inp 
             '(techdisps (foo bar baz) 
                         (foo1 bar1 baz1) 
                         (foo2 bar2 baz2))) 
#;2> inp
(techdisps (foo bar baz) (foo1 bar1 baz1) (foo2 bar2 baz2))
#;3> (define techdisps cdr)
;get all the displays from you input
#;4> (techdisps inp)
((foo bar baz) (foo1 bar1 baz1) (foo2 bar2 baz2))
;this should be just a tech display, let's see how it parses.
#;5> (car (techdisps inp))
(foo bar baz)
#;6> (define foo car)
#;7> (define bar cadr)
#;8> (define baz caddr)
;this will give us all the bazes
#;9> (map baz (techdisps inp))
(baz baz1 baz2)

If you think this won't scale (although 100s more won't be something that a modern scheme interpreter in a decent box will have trouble crunching) we can suggest alternatives. Hope this helps.

Cheers.