command: implement "shapes" match for filter/format chain

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

2 files changed, 47 insertions, 3 deletions

diff --git a/command.py b/command.py
index fc890ba..16e45c6 100644
--- a/command.py
+++ b/command.py
@@ -10,8 +10,12 @@ from optparse import make_option, SUPPRESS_HELP
 
 from .error import ClufterError, \
                    EC
+from .filter import Filter
 from .plugin_registry import PluginRegistry
-from .utils import func_defaults_varnames, \
+from .utils import apply_aggregation_preserving_depth, \
+                   apply_intercalate, \
+                   apply_strict_zip_preserving_depth, \
+                   func_defaults_varnames, \
                    head_tail, \
                    hybridproperty
 
@@ -113,9 +117,32 @@ class Command(object):
         ##print apply_aggregation_preserving_passing_depth(
         ##    lambda x, d: ('\n' + d * ' ') + (' ').join(x)
         ##)(format_chain)
+        # validate format_chain vs chain
+        # 1. "shapes" match
+        check_input, check_output = head_tail(
+            *apply_strict_zip_preserving_depth(self.filter_chain, format_chain)
+        )
+        checked_input = apply_aggregation_preserving_depth(
+            lambda i:
+                head_tail(*i[1])[0] not in i[0].in_format._protocols
+                    and head_tail(*i[1])[0] or None
+                if len(i) == 2 and isinstance(i[0], Filter)
+                else i if any(i) else None
+        )(check_input)
+        checked_output = apply_aggregation_preserving_depth(
+            lambda i:
+                head_tail(*i[1])[0] not in i[0].out_format._protocols
+                    and head_tail(*i[1])[0] or None
+                if len(i) == 2 and isinstance(i[0], Filter)
+                else i if any(i) else None
+        )(check_output)
+        for passno, checked in enumerate((checked_input, checked_output)):
+            for order, cmd in filter(lambda (i, x): x,
+                                     enumerate(apply_intercalate((checked,)))):
+                raise CommandError(self, "filter resolution at #{0} of {1}:"
+                                   " `{2}' protocol not recognized", order + 1,
+                                   ('input', 'output')[passno], cmd)
         # TODO
-        # - validate format_chain vs chain
-        #   1. "shapes" match
         #   2. I/O formats path(s) through the graph exist(s)
         #   3. some per-filter validations?
         #   - could some initial steps be done earlier?
diff --git a/utils.py b/utils.py
index 785bdad..c457bc1 100644
--- a/utils.py
+++ b/utils.py
@@ -45,6 +45,23 @@ apply_intercalate = apply_aggregation_preserving_depth(
                i, [])
 )
 
+zipped_outlier = type('zipped_outlier', (tuple, ), {})
+# NOTE: automatically shortens the longer counterpart in the pair
+#       to the length of the bigger one
+apply_loose_zip_preserving_depth = \
+    lambda a, b: \
+        (type(a) if type(a) == type(b) else type(a))(
+            [apply_loose_zip_preserving_depth(*p) for p in zip(a, b)]
+        ) if isinstance(a, (tuple, list)) == isinstance(b, (tuple, list)) \
+          == True else zipped_outlier([a, b])
+# as previous, but with length checking of some sort
+apply_strict_zip_preserving_depth = \
+    lambda a, b: \
+        (type(a) if type(a) == type(b) else type(a))(
+            [apply_strict_zip_preserving_depth(*p) for p in zip(a, b)]
+        ) if isinstance(a, (tuple, list)) == isinstance(b, (tuple, list)) \
+          == True and len(a) == len(b) else zipped_outlier([a, b])
+
 
 def which(name, *where):
     """Mimic `which' UNIX utility"""