There are many variants of S-Expression <https://en.wikipedia.org/wiki/S-expression>_.
This module here only deals with the prefix notation, where the first element
of an expression is expected to be an operator, which is referred to as the
<key> in this module. The module provides a parser SexpParser that
converts a python list-based expression into a python object model. Each
expression in the list-based S-Expression representation is defined as a
recursive list representation in the form of ::
[ <line number>, <key>, <value>... ]where there may be none or multiple <values> of either an atom (i.e. plain
string) or another list-based S-Expression. SexpParser assumes the <key>
here is a plain string. The <line number> not being part of the
conventional S-Expression is only here for debugging purpose
function parseSexp() can be used to convert plain text form S-Expression into
the list-based representation
The class Sexp is the top class for objects representing a parsed
expression.
If you only need a non-semantic-checking parser, you can use SexpParser as
it is. For the usage of the object model produced by SexpParser, see the
project here <http://github.com/realthunder/kicad_parser>_.
To construct a semantic checking parser, see the sample code here <test.py>_.
More details can be found in the code document here <sexp_parser.py>_