With the forth run of Misc live, you might wonder how to you can quickly write a parser for a cudf document. If you are writing your solver in C / C++ , I advice to either grab the legacy ocaml parser and use the C bindings or reuse a parser written by other competitors (all frontends have a FOSS-compatible licence).
If you want to write a dirty and quick frontend in python, maybe the following 10 lines of python might help you:
from itertools import groupby
cnf_fields = ['conflict','depends','provides','recommends']
def cnf(k,s) :
if k in cnf_fields :
l = s.split(',')
ll = map(lambda s : s.split('|'), l)
return ll
else :
return s
records = []
for empty, record in groupby(open("universe.cudf"), key=str.isspace):
if not empty:
l = map(lambda s : s.split(': '), record)
# we ignore the preamble here ...
if 'preamble' not in l[0] :
pairs = ([k, cnf(k,v.strip())] for k,v in l)
records.append(dict(pairs))
for i in records :
print i
we use the function groupby from itertools to create a list of stanzas and then we just trasfrom each of them in a dictionary that should be pretty easy to manipulate. We ignore the preamble, but adding support for it should be straigthforward… I got the idea from this forum post.
the result :
#python cudf.py
{'recommends': [['perl-modules '], [' libio-socket-inet6-perl']], 'package': '2ping', 'replaces': '', 'number': '1.0-1', 'sourceversion': '1.0-1', 'source': '2ping', 'depends': [['perl']], 'version': '4806', 'architecture': 'all', 'conflicts': '2ping'}0.5-3', 'source': '2vcard', 'version': '1523', 'architecture': 'all', 'conflicts': '2vcard', 'recommends': [['true!']]}'package': '3270-common', 'number': '3.3.10ga4-2', 'sourceversion': '3.3.10ga4-2', 'source': 'ibm-3270', 'depends': [['libc6 >= 9784 '], [' libssl0.9.8 >= 2840']], 'version': '11009', 'architecture': 'amd64', 'conflicts': '3270-common', 'recommends': [['true!']]}chess', 'depends': [['libc6 >= 9578 '], [' libx11-6 '], [' libxext6 '], [' libxmu6 '], [' libxpm4 '], [' libxt6 '], [' xaw3dg >= 6582']], 'version': '2409', 'architecture': 'amd64', 'conflicts': '3dchess', 'recommends': [['true!']]} [' libxpm4 '], [' libxt6 '], [' xaw3dg >= 6582']], 'version': '2410', 'architecture': 'amd64', 'conflicts': '3dchess', 'recommends': [['true!']]}6 >= 8923 '], [' libfreetype6 >= 8856 '], [' libftgl2 >= 8661 '], [' libgcc1 >= 14906 '], [' libgl1-mesa-glx ', ' libgl1--virtual ', ' libgl1 '], [' libglu1-mesa ', ' libglu1--virtual ', ' libglu1 '], [' libgomp1 >= 11829 '], [' libmgl5 '], [' libpng12-0 >= 5996 '], [' libstdc++6 >= 11843 '], [' libwxbase2.8-0 >= 9714 '], [' libwxgtk2.8-0 >= 9714 '], [' libxml2 >= 9624 '], [' zlib1g >= 14223']], 'version': '116', 'architecture': 'amd64', 'conflicts': '3depict', 'recommends': [['true!']]} '], [' libstdc++6 >= 11664 '], [' libwxbase2.8-0 >= 9714 '], [' libwxgtk2.8-0 >= 9714 '], [' libxml2 >= 9624 '], [' zlib1g >= 14223']], 'version': '138', 'architecture': 'amd64', 'conflicts': '3depict', 'recommends': [['true!']]}': '14987', 'architecture': 'amd64', 'conflicts': '9base', 'recommends': [['true!']]}.8-5', 'sourceversion': '1.8-5', 'source': '9menu', 'depends': [['libc6 >= 8923 '], [' libx11-6']], 'version': '7010', 'architecture': 'amd64', 'conflicts': '9menu', 'recommends': [['true!']]}sion': '1.2-9', 'source': '9wm', 'depends': [['libc6 >= 9578 '], [' libx11-6 '], [' libxext6']], 'version': '5712', 'architecture': 'amd64', 'provides': [['x-window-manager--virtual']], 'conflicts': '9wm', 'recommends': [['true!']]}
{'replaces': '', 'package': 'abook', 'number': '0.5.6-7+b1', 'sourceversion': '0.5.6-7', 'source': 'abook', 'depends': [['libc6 >= 9022 '], [' libncursesw5 >= 12348 '], [' libreadline5 >= 12239 '], [' debconf >= 1510 ', ' debconf-2.0--virtual ', ' debconf-2.0']], 'version': '1712', 'architecture': 'amd64', 'conflicts': 'abook', 'recommends': [['true!']]}
...
update
Maybe a small example of the input file would help :)
package: m4
version: 3
depends: libc6 >= 8
package: openssl
version: 11
depends: libc6 >= 18, libssl0.9.8 >= 8, zlib1g >= 1
conflicts: ssleay < 1