A go at creating a prefs2prefs framework. There's a main file, prefs2prefs.py, and two subsidiary files,

prefs2prefs_lfuns.py and prefs2prefs_prefs.py. I've organized it this way because, in many ways, these are
 the same task. It's very line-by-line, unlike lyx2lyx and layout2layout, where things can be more "global". 
So we read the file, line by line, and give a bunch of converter functions a chance to see if they want to 
modify that line.

The converter functions are all in the subsidiary files. (Only the lfun one has anything in it now.) They 
take a line as argument and return a list: (Bool, NewLine), where the Bool says if we've modified anything 
and the NewLine is the new line, if so.

The format of the existing files is format 0, and we'll introduce new format numbers as we proceed, 
just as with layout2layout. So the conversion from format 0 to format 1 will be huge; others will 
generally be simple.



git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@35426 a592a061-630c-0410-9148-cb99ea01b6c8

lib/scripts/prefs2prefs.py

@@ -0,0 +1,191 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# file prefs2prefs.py
+# This file is part of LyX, the document processor.
+# Licence details can be found in the file COPYING.
+
+# author Richard Heck
+
+# Full author contact details are available in file CREDITS
+
+# This is the main file for the user preferences conversion system.
+# There are two subsidiary files:
+# 	prefs2prefs_lfuns.py
+# 	prefs2prefs_prefs.py
+# The former is used to convert bind and ui files; the latter, to convert
+# the preferences file.
+#
+# I've organized it this way because, in many ways, converting bind and ui 
+# files  lfuns) and converting the preferences file are the same task. It's 
+# very line-by-line, unlike lyx2lyx and layout2layout, where changes can be 
+# more "global". So we read the file, line by line, and give a bunch of 
+# converter functions a chance to see if they want to modify that line.
+
+# The converter functions are all in the subsidiary files. They take a line 
+# as  argument and return a list: (Bool, NewLine), where the Bool says if 
+# we've modified anything and the NewLine is the new line, if so, which will
+# be used to replace the old line.
+
+# The format of the existing files is format 0, as of 2.0.alpha6. We'll 
+# introduce new format numbers as we proceed, just as with layout2layout.
+# These will be different for the bind and ui files and for the preferences
+# file. 
+
+import os, re, string, sys
+from getopt import getopt
+
+###########################################################
+# Utility functions, borrowed from layout2layout.py
+
+def trim_bom(line):
+	" Remove byte order mark."
+	if line[0:3] == "\357\273\277":
+		return line[3:]
+	else:
+		return 	line
+
+
+def read(source):
+	" Read input file and strip lineendings."
+	lines = source.read().splitlines()
+	lines[0] = trim_bom(lines[0])
+	return lines
+
+
+def write(output, lines):
+	" Write output file with native lineendings."
+	output.write(os.linesep.join(lines) + os.linesep)
+
+
+# for use by find_format_lines
+re_comment = re.compile(r'^#')
+re_empty   = re.compile(r'^\s*$')
+
+def find_format_line(lines):
+	'''
+	Returns (bool, int), where int is number of the line the `Format' 
+	specification is on, or else the number of the first non-blank, 
+	non-comment line. The bool tells whether we found a format line.
+	'''
+	for i in range(len(lines)):
+		l = lines[i]
+		if re_comment.search(l) or re_empty.search(l):
+			continue
+		m = re_format.search(l)
+		if m:
+			return (True, i)
+		# we're done when we have hit a non-comment, non-empty line
+		break
+	return (False, i)
+
+
+# for use by get_format
+re_format  = re.compile(r'^Format\s+(\d+)\s*$')
+
+def get_format(lines):
+	" Gets format of current file and replaces the format line with a new one "
+	(found, format_line) = find_format_line(lines)
+	if not found:
+		return 0
+	line = lines[format_line]
+	m = re_format.search(line)
+	if not m:
+		sys.stderr.write("Couldn't match format line!\n" + line + "\n")
+		sys.exit(1)
+	return int(m.group(1))
+
+
+def update_format(lines):
+	" Writes new format line "
+	(found, format_line) = find_format_line(lines)
+	if not found:
+		lines.insert(format_line, "Format 1")
+		return
+
+	line = lines[format_line]
+	m = re_format.search(l)
+	if not m:
+		sys.stderr.write("Couldn't match format line!\n" + line + "\n")
+		sys.exit(1)
+	format = int(m.group(1))
+	lines[i] = "Format " + str(format + 1)
+
+
+#
+###########################################################
+
+def usage():
+	print "%s [-l] [-p] infile outfile" % sys.argv[0]
+	print "or: %s [-l] [-p] <infile >outfile" % sys.argv[0]
+	print "  -l: convert LFUNs (bind and ui files)"
+	print "  -p: convert preferences"
+	print "Note that one of -l and -p is required."
+
+
+def main(argv):
+	try:
+		(options, args) = getopt(sys.argv[1:], "lp")
+	except:
+		usage()
+		print "\nUnrecognized option"
+		sys.exit(1)
+
+	opened_files = False
+	# Open files
+	if len(args) == 0:
+		source = sys.stdin
+		output = sys.stdout
+	elif len(args) == 2:
+		source = open(args[1], 'rb')
+		output = open(args[2], 'wb')
+		opened_files = True
+	else:
+		usage()
+		print "\nEither zero or two arguments must be given."
+		sys.exit(1)
+
+	conversions = False
+
+	for (opt, param) in options:
+		if opt == "-l":
+			from prefs2prefs_lfuns import conversions, current_format
+		elif opt == "-p":
+			from prefs2prefs_prefs import conversions, current_format
+	
+	if not conversions:
+		usage()
+		print "\nNeither -l nor -p given"
+		sys.exit(1)
+
+	lines = read(source)
+	format = get_format(lines)
+
+	while format < current_format:
+		for c in conversions[format]:
+			for i in range(len(lines)):
+				(update, newline) = c(lines[i])
+				if update:
+					lines[i] = newline
+
+		update_format(lines)
+
+		# sanity check
+		old_format = format
+		format = get_format(lines)
+		if int(old_format) + 1 != int(format):
+			sys.stderr.write("Failed to convert to new format!\n")
+			sys.exit(1)
+
+	write(output, lines)
+
+	# Close files
+	if opened_files:
+		source.close()
+		output.close()
+
+	return 0
+
+
+if __name__ == "__main__":
+    main(sys.argv)

lib/scripts/prefs2prefs_lfuns.py

@@ -0,0 +1,63 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# file prefs2prefs-lfuns.py
+# This file is part of LyX, the document processor.
+# Licence details can be found in the file COPYING.
+
+# author Richard Heck
+
+# Full author contact details are available in file CREDITS
+
+# This file houses conversion information for the bind and ui files,
+# i.e., for files where we are converting lfuns.
+
+# The converter functions take a line as argument and return a list: 
+# 	(Bool, NewLine), 
+# where the Bool says if  we've modified anything and the NewLine is 
+# the new line, if so, which will be used to replace the old line.
+
+
+import sys, re
+
+current_format = 1
+
+###########################################################
+#
+# Actual converter functions
+#
+# These accept a line as argument and should return a list:
+#  (bool, newline)
+# where the bool indicates whether we changed anything. In 
+# that case, one normally returns: (False, []).
+
+
+def simple_renaming(line, old, new):
+	if line.find(old) == -1:
+		return (False, [])
+	line = line.replace(old, new)
+	return (True, line)
+
+
+def next_inset_modify(line):
+	return simple_renaming(line, "next-inset-modify", "inset-modify")
+
+
+def next_inset_toggle(line):
+	return simple_renaming(line, "next-inset-toggle", "inset-toggle")
+
+
+#
+#
+###########################################################
+
+
+# Conversion chain
+
+conversions = [
+	[ # this will be a long list of conversions for format 0
+		next_inset_toggle,
+		next_inset_modify
+	] # end conversions for format 0
+]
+

lib/scripts/prefs2prefs_prefs.py

@@ -0,0 +1,30 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# file prefs2prefs-lfuns.py
+# This file is part of LyX, the document processor.
+# Licence details can be found in the file COPYING.
+
+# author Richard Heck
+
+# Full author contact details are available in file CREDITS
+
+# This file houses conversion information for the preferences file.
+
+# The converter functions take a line as argument and return a list: 
+# 	(Bool, NewLine), 
+# where the Bool says if  we've modified anything and the NewLine is 
+# the new line, if so, which will be used to replace the old line.
+
+
+current_format = 1
+
+###########################################################
+#
+# Conversion chain
+
+conversions = [
+	[ # this will be a long list of conversions for format 0
+		
+	] # end conversions for format 0
+]