TODO

Known Bugs
----------
- doc strings aren't extracted correctly if there are empty comment lines after
  the ';-' one (need to strip those)

Conversion
----------
- have option of producing "bad" output for unconvertible IDL constructs (JH)
  (partially implemented by TG, but as behaviour, not optional)
- implement assignment and increment as expressions
  (not sure this can be done in Python)
- figure out a way to preserve line breaks (and comments) with '$'

Mappings
--------
- think of something to do with WHERE and other functions that use output
  parameters/keywords




IDL vs. Python issues to deal with
----------------------------------
- This is valid in IDL but not Python/numarray (you can index scalars in IDL):

    a = 3
    b = a[0]

- This is really annoying:

    IDL> print,-(3/2) eq (-3)/2
       1

    >>> -(3/2) == (-3)/2
    False
    >>> -(3/2), (-3)/2
    (-1, -2)

- What the *&$! is up with this?
  (TG: This is binary floating-point inability to represent 0.1 exactly)

    IDL> for z = 1.0, 5.0, 1.0 do print, z
          1.00000
          2.00000
          3.00000
          4.00000
          5.00000
    IDL> for z = 0.1, 0.5, 0.1 do print, z
         0.100000
         0.200000
         0.300000
         0.400000
    IDL>