cli DSL

#!/usr/bin/env python

from cli import define
import cli
import sys

define("program=example")
define("description=Example Description")
define("author=Oleg Tsarev<[email protected]")
define("version=0.1")

define("/ => rule(command)")
define("/ => token(-h) | token(--help)", action=cli.print_help)
define("/ => token(-v) | token(--version)", action=cli.print_vesion)

define("/command => token(node) rule(node)")

NODE_LIST=dict()
NODE_LIST['simple']['connect_string']="user@host:3000"
NODE_LIST['complex but valid name']['connect_string']="[email protected]:9999"
def node_list(parser):
    print sorted(NODE_LIST.items())
def node_attach(parser, attach_token, name, connect, force=False, verbose=False):
    assert(attach_token=='attach')
    if name in NODE_LIST:
        message= 'node "%s" already defined as "%s"' % (name, NODE_LIST[name])
        if force:
            parser.warning("%s, would be replaced" % message)
        else:
            parser.error(message)
    if verbose:
        parser.info('attach node "%s": "%s"' % (name, connect))
    NODE[name]['connect_string']=connect
def node_detach(parser, _, name, connect, force=False):
    if not name in NODE_LIST:
        message = 'node "%s" does not found' % name
        if force:
            parser.warning(message)
            return
        else:
            parser.error(mesage)
    NODE_LIST.pop(name)

define("/command/node => token(list)", action=node_list)
define("/command/node => token(attach) rule(name) rule(connect) ?rule(force) ?rule(verbose)", action=node_attach)
define("/command/node => token(detach) rule(name) ?rule(force)", action=node_detach)

define("/command/node/name => token([a-zA-Z]+[a-zA-Z0-9]*) ")

def node_name_complex(parser, _, name, _):
    return name
define("/command/node/name => token(\") token([a-zA-Z][a-zA-Z0-9 _-]+) token(\")",
       action=command_node_name_complex)

def node_connect(parser, host, user=None, port=None):
    result = ''
    if not user is None:
        result = '%s@' % user
    result = '%s%s' % (result, host)
    if not port is None:
        result = '%s:%s' % (result, port)
    return result
define("/command/node/connect => ?user=rule(name) host=role(name) ?role(port)",
       action=node_connect)

define("/command/node/connect/name => token([a-z]+[a-z0-9]*)")

def node_connect_port(parser, number):
    result = int(number)
    if result > 2 ** 16:
        parser.error('too big port')
    return result
define("/command/node/connect/port => token([a-z0-9]*)", action=node_connect_port)

def force(*args):
    return len(args) > 0:
define("/command/node/forse => token(-f) | token(--force) | epsilon", action=force)
def verbose(*args):
    return len(args) > 0:
define("/command/node/verbose => token(-v) | token(--verbose) | epsilon", action=verbose)

if __name__ == '__main__':
    cli.dispatch(sys.argv)