mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
87 lines
2.5 KiB
87 lines
2.5 KiB
3 years ago
|
# SEXP (S-expressions) Basic Transport Support
|
||
|
|
#
|
||
|
|
# See: http://people.csail.mit.edu/rivest/sexp.html
|
||
|
|
#
|
||
|
|
"""
|
||
|
|
sexp.py - a library for SEXP
|
||
|
|
|
||
|
|
Copyright (C) 2013 Free Software Initiative of Japan
|
||
|
|
Author: NIIBE Yutaka <gniibe@fsij.org>
|
||
|
|
|
||
|
|
This file is a part of Gnuk, a GnuPG USB Token implementation.
|
||
|
|
|
||
|
|
Gnuk is free software: you can redistribute it and/or modify it
|
||
|
|
under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation, either version 3 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
Gnuk is distributed in the hope that it will be useful, but WITHOUT
|
||
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
||
|
|
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
|
||
|
|
License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import re
|
||
|
|
|
||
|
|
WHITESPACE='[ \n\t\v\r\f]+'
|
||
|
|
re_ws = re.compile(WHITESPACE)
|
||
|
|
DIGITS='[0-9]+'
|
||
|
|
re_digit = re.compile(DIGITS)
|
||
|
|
|
||
|
|
def skip_whitespace(string, pos):
|
||
|
|
m = re_ws.match(string, pos)
|
||
|
|
if m:
|
||
|
|
return m.start()
|
||
|
|
else:
|
||
|
|
return pos
|
||
|
|
|
||
|
|
def sexp_match(string, ch, pos):
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
if string[pos] == ch:
|
||
|
|
return pos+1
|
||
|
|
else:
|
||
|
|
raise ValueError("expect '%s'" % ch)
|
||
|
|
|
||
|
|
def sexp_parse_simple_string(string, pos):
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
m = re_digit.match(string, pos)
|
||
|
|
if m:
|
||
|
|
length = int(string[m.start():m.end()],10)
|
||
|
|
pos = sexp_match(string, ':', m.end())
|
||
|
|
return (string[pos:pos+length], pos+length)
|
||
|
|
else:
|
||
|
|
raise ValueError('expect digit')
|
||
|
|
|
||
|
|
def sexp_parse_list(string,pos):
|
||
|
|
l = []
|
||
|
|
while True:
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
if string[pos] == ')':
|
||
|
|
return (l, pos)
|
||
|
|
else:
|
||
|
|
(sexp, pos) = sexp_parse(string,pos)
|
||
|
|
l.append(sexp)
|
||
|
|
|
||
|
|
def sexp_parse(string, pos=0):
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
if string[pos] == '(':
|
||
|
|
(l, pos) = sexp_parse_list(string,pos+1)
|
||
|
|
pos = sexp_match(string, ')', pos)
|
||
|
|
return (l, pos)
|
||
|
|
elif string[pos] == '[':
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
(dsp, pos) = sexp_parse_simple_string(string,pos+1)
|
||
|
|
pos = sexp_match(string, ']', pos)
|
||
|
|
pos = skip_whitespace(string,pos)
|
||
|
|
(ss, pos) = sexp_parse_simple_string(string, pos)
|
||
|
|
return ((dsp, ss), pos)
|
||
|
|
else:
|
||
|
|
return sexp_parse_simple_string(string, pos)
|
||
|
|
|
||
|
|
def sexp(string):
|
||
|
|
(sexp, pos) = sexp_parse(string)
|
||
|
|
return sexp
|