* Daniele Tricoli <er...@mornie.org>, 2011-05-25, 02:33:
I'm working on #555363 to get rid of embedded copy of python-ply from
python-pyke.
python-pyke ships some tables with _tabversion="3.2" so it can right
use python-ply 3.3-1 and also (when it will be packaged) ply 3.4 which
use the same table version without rebuilding cached tables.
If you can provide a virtual package, e.g. python-ply-X.Y, where X.Y is
the required table version, other packages could simply depend on the
virtual package, without having to anticipate when the compatibility
will break.
Here's a patch implementing this. I use two virtual packages, because
version number embedded in lextab and parsetab can differ (and some
users might don't care about lextab at all, since it's not stored on
disk by default).
The only missing bit, which would be nice to have, is a script to
automatically generate correct dependencies on these virtual packages
for packages that ship pre-generatare parser/lexer tables.
--
Jakub Wilk
diff --git a/debian/control b/debian/control
--- a/debian/control
+++ b/debian/control
@@ -17,6 +17,7 @@
Package: python-ply
Architecture: all
Depends: ${python:Depends}, ${misc:Depends}
+Provides: ${python-ply:Provides}
Suggests: python-ply-doc, python-pkg-resources
Description: Lex and Yacc implementation for Python
PLY is yet another implementation of lex and yacc for
diff --git a/debian/rules b/debian/rules
--- a/debian/rules
+++ b/debian/rules
@@ -11,3 +11,6 @@
DEB_DESTDIR := debian/python-ply
DEB_PYTHON_INSTALL_ARGS_ALL += --single-version-externally-managed
+
+binary-post-install/python-ply::
+ echo "python-ply:Provides=$$(python debian/virtual-packages.py)" >> debian/python-ply.substvars
diff --git a/debian/virtual-packages.py b/debian/virtual-packages.py
new file mode 100644
--- /dev/null
+++ b/debian/virtual-packages.py
@@ -0,0 +1,43 @@
+#!/usr/bin/python
+
+import os
+import shutil
+import tempfile
+
+import ply.lex
+import ply.yacc
+
+tokens = ['token']
+
+t_token = 'x'
+
+def t_error(t):
+ pass
+
+def p_dummy(p):
+ 'dummy : token'
+ pass
+
+def p_error(p):
+ pass
+
+def read_tabversion(filename):
+ file = open(filename)
+ data = {}
+ try:
+ exec file in data
+ finally:
+ file.close()
+ return data['_tabversion']
+
+tmpdir = tempfile.mkdtemp()
+try:
+ ply.lex.lex(outputdir=tmpdir, optimize=True)
+ ply.yacc.yacc(outputdir=tmpdir, optimize=True, debug=False)
+ lex_tabversion = read_tabversion(os.path.join(tmpdir, 'lextab.py'))
+ yacc_tabversion = read_tabversion(os.path.join(tmpdir, 'parsetab.py'))
+ print 'python-ply-lex-%s, python-ply-yacc-%s' % (lex_tabversion, yacc_tabversion)
+finally:
+ shutil.rmtree(tmpdir)
+
+# vim:ts=4 sw=4 et
