filters/cmd-wrap: new filter (promoting command format)

Signed-off-by: Jan Pokorný <jpokorny@redhat.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/formats/command.py b/formats/command.py
new file mode 100644
index 0000000..04a49ad
--- /dev/null
+++ b/formats/command.py
@@ -0,0 +1,95 @@
+# -*- coding: UTF-8 -*-
+# Copyright 2015 Red Hat, Inc.
+# Part of clufter project
+# Licensed under GPLv2+ (a copy included | http://gnu.org/licenses/gpl-2.0.txt)
+"""Format representing merged/isolated (1/2 levels) of single command to exec"""
+__author__ = "Jan Pokorný <jpokorny @at@ Red Hat .dot. com>"
+
+try:
+    from collections import OrderedDict
+except ImportError:
+    from ordereddict import OrderedDict
+from logging import getLogger
+
+log = getLogger(__name__)
+
+from ..format import SimpleFormat
+from ..protocol import Protocol
+from ..utils import head_tail
+from ..utils_func import apply_intercalate
+
+
+class command(SimpleFormat):
+    native_protocol = SEPARATED = Protocol('separated')
+    BYTESTRING = SimpleFormat.BYTESTRING
+    DICT = Protocol('dict')
+    MERGED = Protocol('merged')
+
+    @SimpleFormat.producing(BYTESTRING, chained=True)
+    def get_bytestring(self, *protodecl):
+        """Return command as canonical single string"""
+        # chained fallback
+        return ' '.join(self.MERGED(protect_safe=True))
+
+    @SimpleFormat.producing(SEPARATED, protect=True)
+    def get_separated(self, *protodecl):
+        merged = self.MERGED()
+        merged.reverse()
+        ret, acc = [], []
+        while merged:
+            i = merged.pop()
+            if acc == ['--'] or i is None or i.startswith('-') and i != '-':
+                if acc:
+                    ret.append(tuple(acc))
+                acc = [] if i is None else [i]
+            elif self._dict.get('magic_split', False):
+                acc.extend(i.split('::'))  # magic "::"-split
+                merged.append(None)
+            else:
+                acc.append(i)
+        # expect that, by convention, option takes at most a single argument
+        ret.extend(filter(bool, (tuple(acc[:2]), tuple(acc[2:]))))
+        return ret
+
+    @SimpleFormat.producing(MERGED, protect=True)
+    def get_merged(self, *protodecl):
+        # try to look (indirectly) if we have "separated" at hand first
+        if self.BYTESTRING in self._representations:  # break the possible loop
+            from shlex import split
+            ret = split(self.BYTESTRING())
+            for i, lexeme in enumerate(ret[:]):
+                # heuristic(!) method to normalize: '-a=b' -> '-a', 'b'
+                if (lexeme.count('=') == 1 and
+                    ('"' not in lexeme or lexeme.count('"') % 2) and
+                    ("'" not in lexeme or lexeme.count("'") % 2)):
+                    ret[i:i + 1] = lexeme.split('=')
+        elif self.DICT in self._representations:  # break the possible loop (2)
+            d = self.DICT(protect_safe=True)
+            if not isinstance(d, OrderedDict):
+                log.warning("'{0}' format: not backed by OrderedDict".format(
+                    self.__class__.name
+                ))
+            ret = list(d.get('__cmd__', ()))
+            ret.extend((k, v) for k, vs in d.iteritems() for v in (vs or ((), ))
+                                  if k not in ('__cmd__', '__args__'))
+            ret.extend(d.get('__args__', ()))
+        else:
+            ret = self.SEPARATED(protect_safe=True)
+        return apply_intercalate(ret)
+
+    @SimpleFormat.producing(DICT, protect=True)
+    # not a perfectly bijective mapping, this is a bit lossy representation,
+    # on the other hand it canonicalizes the notation when turned to other forms
+    def get_dict(self, *protodecl):
+        separated = self.SEPARATED()
+        separated.reverse()
+        ret = OrderedDict()
+        arg_bucket = '__cmd__'
+        while separated:
+            head, tail = head_tail(separated.pop())
+            if head.startswith('-') and head != '-':
+                arg_bucket = '__args__'
+            else:
+                head, tail = arg_bucket, head
+            ret.setdefault(head, []).append(tail)
+        return ret