ABSTRACT
========
This is a test for a parser for a configuration file for 
abstract syntax trees (AST). It's written with bison and
flex.

HOW TO INSTALL AND RUN
======================
    mkdir build
    cd build
    ../configure --prefix=$(pwd)
    make install
    cd ../test
    ../build/bin/iotest
    
FILES
=====

* test:

- conf.txt: A sample configuration

* In src:

- test.cc: a small test program that reads in the configuration file
conf.txt and outputs the constructed AST again.

* In src/parser:

- scanner.ll, scanner.h: Contains the lexer, which reads in
a file and returns tokens and their values. Nicely packed 
into a class called Scanner.

- parser.yy: Contains the parser, who parses the tokens
from the Scanner class and interprets it according to a 
grammer.

- driver.h, driver.cc: Glues together the lexer and the parser.
Basically the Interface for the whole parser.

* in src/ast:

- ast.h, ast.cc: The actual AST with list, object and simple items.

- node.h, node.cc: The Node class provides an interface for the AST
and the NodeIterator provides an iterator. The Node doesn't delete 
the AST to which it is pointed to, while the class Root does,
when it goes out of scope.

- node_operator.h, node_operator.cc: The actual implementation details
for Node and NodeIterator


GRAMMER
=======

This is the grammer of the configuration file in EBNF:
    
    root   = object
    object = '{' {field} '}'
    field  = key '=' value
    key    = WORD
    value  = item | list | object
    list   = '[' {value} ']'
    item   = DOUBLE | INT | STRING

where the terminals are defined in terms of REGEX's

    INT     [0-9]*
    DOUBLE  [0-9]*\.[0-9]*
    WORD    [[:alnum:]]*
    STRING  ["][^"\n]*["]
    COMMENT //[^\n]*\n