Thorsten Froehlich <tho### [at] trfde> wrote:
> That may or may not be desirable. Usually it actually is not, as it has a
> serious negative effect on performance.

  Serious negative performance? Like eg. parsing goes 1% slower?

  Switch-case blocks are not that much faster compared to dynamic binding.
Besides I clearly remember you saying in the past that the parsing of the
input file itself is not by far the slowest operation done at the parsing
stage (but allocating and initializing objects).

> Not to mention that is is not
> actually possible if the parser is part of a public interface, where you of
> course always have header and source file that need to be modified.

  Why would the public interface of the parser have any info on the
implementation details of the input file?

  A well-implemented parser *abstracts* away these implementation details.
The user of the parser is not interested in knowing whether a sphere is
created with the keyword "sphere", "Sphere" or "ball". The user of the
parser is only interested in getting the objects (in an abstract way).
Putting implementation details in the public interface is only going
to cause problems: Code around the entire application may start being
dependant on those implementation details, making it harder to modify.

  I see no reason why adding a new token could not be done by simply
adding the name of a new class in one .cpp file (besides implementing
that new class, of course).

-- 
                                                          - Warp

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