mconfig.py progress

1 files changed, 219 insertions, 0 deletions

diff --git a/mconfig.py b/mconfig.py
new file mode 100644
index 0000000..80e365b
--- /dev/null
+++ b/mconfig.py
@@ -0,0 +1,219 @@
+import re, argparse, sys, os
+from collections import OrderedDict, namedtuple
+import curses.ascii
+
+def indentify(s, indent='    '):
+    return s.replace('\n', '\n' + indent)
+
+def argv_to_shell(argv):
+    quoteds = []
+    for arg in argv:
+        if re.match('^[a-zA-Z0-9_\.@/+-]+$', arg):
+            quoteds.append(arg)
+        else:
+            quoted = ''
+            for c in arg:
+                if c == '\n':
+                    quoted += r'\n'
+                elif c in r'$`\"':
+                    quoted += '\\' + c
+                elif not curses.ascii.isprint(c):
+                    quoted += r'\x%02x' % ord(c)
+                else:
+                    quoted += c
+            quoteds.append('"' + quoted + '"')
+    return ' '.join(quoteds)
+
+class PendingOption(namedtuple('PendingOption', 'opt')):
+    def need(self):
+        self.opt.show = True
+    def __str__(self):
+        return 'PendingOption(%s)' % (self.opt.name,)
+
+class SettingsGroup(object):
+    def __init__(self, parent=None):
+        object.__setattr__(self, 'parent', parent)
+        object.__setattr__(self, 'vals', OrderedDict())
+    @staticmethod
+    def get_meat(self, attr, exctype):
+        try:
+            obj = object.__getattribute__(self, 'vals')[attr]
+        except KeyError:
+            if self.parent is not None:
+                return SettingsGroup.get_meat(object.__getattribute__(self, 'parent'), attr, exctype)
+            raise exctype(attr)
+        else:
+            if isinstance(obj, PendingOption):
+                raise Exception("setting %s is pending a command line option, probably because you didn't 'need' it")
+            return obj
+    def __getattribute__(self, attr):
+        try:
+            return object.__getattribute__(self, attr)
+        except AttributeError:
+            return SettingsGroup.get_meat(self, attr, AttributeError)
+    def __setattr__(self, attr, val):
+        try:
+            object.__getattribute__(self, attr)
+        except:
+            self[attr] = val
+        else:
+            object.__setattribute__(self, attr, val)
+    def __getitem__(self, attr):
+        return self.__getattribute__(attr)
+    def __setitem__(self, attr, val):
+        self.vals[attr] = val
+
+    def __iter__(self):
+        return self.vals.__iter__()
+    def items(self):
+        return self.vals.items()
+
+    def __str__(self):
+        s = 'SettingsGroup {\n'
+        for attr, val in self.vals.items():
+            s += '    %s: %s\n' % (attr, indentify(str(val)))
+        s += '}'
+        return s
+
+    def relative_lookup(name):
+        if name.startswith('..'):
+            return self.parent.relative_lookup(name)
+        else:
+            bits = name.split('.', 1)
+            if len(bits) == 1:
+                return (self, bits[0])
+            else:
+                return self[bits[0]].relative_lookup(bits[1])
+    def need(self, name):
+        if name not in self.vals:
+            raise KeyError('need setting that has not been set')
+        obj = self.vals[name]
+        if hasattr(obj, 'need'):
+            obj.need()
+
+    def add_setting_option(self, name, optname, optdesc, default, **kwargs):
+        def f(value):
+            self[name] = value
+        opt = Option(optname, optdesc, default, f, **kwargs)
+        self[name] = PendingOption(opt)
+
+class OptSection(object):
+    def __init__(self, desc):
+        self.desc = desc
+        self.opts = []
+        all_opt_sections.append(self)
+    def move_to_end(self):
+        all_opt_sections.remove(self)
+        all_opt_sections.append(self)
+
+class Option(object):
+    def __init__(self, name, help, default, on_set, bool=False, show=False, section=None, **kwargs):
+        self.name = name
+        self.help = help
+        self.default = Expansion(default) if isinstance(default, str) else default
+        self.on_set = on_set
+        self.show = show
+        self.bool = bool
+        self.section = section if section is not None else default_opt_section
+        self.section.opts.append(self)
+        assert set(kwargs).issubset({'nargs', 'type', 'choices', 'required', 'metavar'})
+        self.argparse_kw = kwargs.copy()
+        all_options.append(self)
+        if name in all_options_by_name:
+            raise KeyError('trying to create Option with duplicate name %r; old is:\n%r' % (name, all_options_by_name[name]))
+        all_options_by_name[name] = self
+    def __repr__(self):
+        return 'Option(name=%r, help=%r, value=%r, default=%r)' % (self.name, self.help, self.value, self.default)
+    def set(self, value):
+        self.value = value
+        if self.on_set is not None:
+            self.on_set(value)
+
+class Expansion(object):
+    def __init__(self, fmt):
+        self.fmt = fmt
+        self.deps = re.findall('\((.*?)\)', fmt)
+    def __repr__(self):
+        return 'Expansion(%r)' % (self.fmt,)
+
+class InstallationDirsGroup(SettingsGroup):
+    def __init__(self):
+        section = OptSection('Fine tuning of the installation directories:')
+        SettingsGroup.__init__(self)
+        for name, optname, optdesc, default in [
+            ('prefix', 'prefix', '', '/usr/local'),
+            ('exec_prefix', 'exec-prefix', '', '(prefix)'),
+            ('bin', 'bindir', '', '(exec_prefix)/bin'),
+            ('sbin', 'sbindir', '', '(exec_prefix)/sbin'),
+            ('libexec', 'libexecdir', '', '(exec_prefix)/libexec'),
+            ('etc', 'sysconfdir', '', '(prefix)/etc'),
+            ('var', 'localstatedir', '', '(prefix)/var'),
+            ('lib', 'libdir', '', '(prefix)/lib'),
+            ('include', 'includedir', '', '(prefix)/include'),
+            ('datarootdir', 'datarootdir', '', '(prefix)/share'),
+            ('share', 'datadir', '', '(datarootdir)'),
+            ('locale', 'localedir', '', '(datarootdir)/locale'),
+            ('man', 'mandir', '', '(datarootdir)/man'),
+            ('doc', 'docdir', '', '(datarootdir)/doc/(..package_unix_name)'),
+            ('html', 'htmldir', '', '(doc)'),
+            ('pdf', 'pdfdir', '', '(doc)'),
+        ]:
+            self.add_setting_option(name, optname, optdesc, default, section=section)
+        for ignored in ['sharedstatedir', 'oldincludedir', 'infodir', 'dvidir', 'psdir']:
+            Option(ignored, 'Ignored autotools compatibility setting', '', None, section=section)
+
+def _make_argparse(include_all):
+    parser = argparse.ArgumentParser(add_help=False, usage='configure [OPTION]... [VAR=VALUE]...')
+    parser.add_argument('--help', action='store_true', help='Show this help', dest='__help')
+    parser.add_argument('--help-all', action='help', help='Show this help, including unused options')
+    for sect in all_opt_sections:
+        if not include_all and not any(opt.show for opt in sect.opts):
+            continue
+        ag = parser.add_argument_group(description=sect.desc)
+        for opt in sect.opts:
+            if not include_all and not opt.show: continue
+            ag.add_argument('--' + opt.name,
+                            action='store_true' if opt.bool else 'store',
+                            dest=opt.name,
+                            help=opt.help,
+                            **opt.argparse_kw)
+    return parser
+
+def parse_args():
+    default_opt_section.move_to_end()
+    parser = _make_argparse(include_all=True)
+    args, argv = parser.parse_known_args()
+    if args.__help:
+        parser = _make_argparse(include_all=False)
+        parser.print_help()
+        sys.exit(0)
+    def do_env_arg(arg):
+        m = re.match('([^ ]+)=(.*)', arg)
+        if m:
+            os.environ[m.group(1)] = m.group(2)
+            return False
+        return True
+    argv = list(filter(do_env_arg, argv))
+    if argv:
+        parser = _make_argparse(include_all=False)
+        parser.error('unrecognized arguments: %s' % (argv_to_shell(argv),))
+
+    for opt in all_options:
+        opt.set(getattr(args, opt.name))
+
+
+all_options = []
+all_options_by_name = {}
+all_opt_sections = []
+default_opt_section = OptSection('Uncategorized options:')
+
+settings_root = SettingsGroup()
+settings_root.idirs = InstallationDirsGroup()
+
+# --
+settings_root.package_unix_name = 'substitute'
+settings_root.idirs.need('pdf')
+
+parse_args()
+print settings_root
+